# Riving knife retrofit for unisaw



## runswithscissors (Nov 8, 2012)

*Riving Knife retrofit for Unisaw*

Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.

I find this analogy useful for picturing the functioning of a true riving knife. Compare it to your arm. Your shoulder represents the pivot point of the swing arm; your elbow represents the blade arbor; and your forearm represents the articulating arm, with the riving knife held in your fist. Now, hold your arm straight out and level with the floor. This represents the blade (and RK) at full height. Then, lower your arm slowly, always keeping your forearm level with the floor. Notice that to do this, you have to gradually bend your arm at the elbow. (If you are resistant to my suggestion to physically do this, at least imagine it.). If you can figure out how to do this on your saw, you can have a true riving knife.

I live close enough to the Bellingham Grizzly that it was convenient to go in and check out their saws. They have at least 3 different mechanisms for keeping the RK level with the blade. One avoids the swing arm altogether, and simply moves the arbor and RK straight up and down (I say "simply" because I couldn't see the mechanism that does this; it may be very complicated). Another swing arm mount uses 2 toothed plates separated by a cog that rotates between them. Though I cranked this mechanism up and down several times, I couldn't really see how it worked either. But it looked too complicated for me to attempt. The third used a swing arm, with "forearm" actuated by some sort of linkage, but again, I couldn't see enough of it to understand exactly how it works. I suspect my method most closely resembles it in principle. It would be fun to take these machines apart to better understand their mechanisms.

I decided that the best way to accomplish what I wanted was to make a joint at the "elbow" part that could slip over the blade's arbor flange. This would make it unnecessary to remove the arbor shaft. As the articulating arm (forearm) had to have a solid base, I had to figure out where and how this could be mounted. The arbor casting is somewhat triangular in shape, with the blade shaft forming one corner, swing arm pivot another, and worm driven gear for changing blade height the third. Within this triangle is a sort of web of cast iron (like a duck's foot web, not a spider web). It would have been ideal if this web had been flat and coplanar with the rest of the arbor and table. But it was neither. So I tried bolting a plate (1/4" steel) to this by using spacers (small-diameter bits of tubing or pipe tack-welded on), ranging from about 3/8" to slightly more than 1/2" in length). After welding these spacers on, I could drill 5/16 holes for mounting bolts, and then, using a depth gauge, determine how much to grind off the spacers. I used 3 bolts, figuring I would need that many to have a solid mounting. The bolts tap into the cast iron web.

I then cut the hole in this plate so it could slide over the arbor flange. A 2 1/2" hole saw was about right for this, requiring a little enlarging on the oscillating spindle sander, only a few minutes worth. The "forearm" needed the same hole. To achieve concentric pivoting at the elbow, I cut three 1/4" wide arced slots about 1/4" out from the 2 1/2" hole, and concentric to it, and then bored and tapped 1/4" holes into the "forearm." (The slots were in the mounting base). Wanting to have smooth studs (rather than threads) to run in the slots, I ran the threads down on the bolts to leave 1/4" of smooth shank, and enough thread to tighten while allowing free movement of the arm without wiggle. One bolt head had to be ground thinner to not clash with the arbor casting; one head had to be removed altogether for the same reason, leaving just a stud, but the remaining 2 were sufficient to hold everything in place. Those bolts (on final assembly), were put in with medium strength Locktite. When in the horizontal (full up) position, these concentric plates have a gap at the top about 1 1/4" wide. This is partly because it would be too high otherwise, and would interfere with the throat plate, and also because my Uni has flats on the shaft that accept a wrench for blade changing (a really nice feature that I've seen on very few saws). So I did not have to sacrifice this blade changing aid, for which I am grateful.

All the above was relatively straightforward (but made harder because I hadn't removed the table, and had to do everything reaching through the throat). Drilling holes for the mounting bolts was a real challenge, requiring a right angle drill and a drill bit I'd cut in half. I only had to attach and remove everything about 50 times to make small corrections and adjustments.

The tougher problem lay in figuring out how to actuate the forearm to make it rise and fall proportionally with the blade. I cut out poster board mockups of various schemes and pinned them to a piece of plywood, with pivots consisting of brass binder clasps. Everything I tried simply didn't work. Spent a lot of sleepless nights puzzling over this. Finally, one idea I hit upon actually showed promise. I finally tried this scheme, using a mockup made from angle iron and a piece of 1/4" hardboard, and to my amazement, it did work. But there were two problems with it: it took up too much space where the riving knife was to go; and it required a precisely dimensioned, precisely curved slot. I hesitated.

About that time, I ran into a blog by TTalma showing an arrangement similar to mine, and he revealed the necessary placement and configuration of the actuating arm I had been struggling with. Once I had this conundrum resolved, I tried it and it worked. And I'm very pleased with the results.

At least two others have worked out schemes similar to mine, and they are worth checking out if you plan to try your own. In some ways, theirs are superior to mine (except in functionality) as they are skillfully machined and nicely finished (see TTalma"s blog "Home made riving knife," and a SMC thread titled "Delta 34-350 12-14" riving knife retrofit"). Mine is crude, and plenty ugly, and shows signs of extensive trial and error-weldments, holes without meaning and even a slot with (now) no purpose. Several times, I had to cut something off and weld something else back on.

To follow my design, you would need a means to cut steel (I use a 4 1/2" angle grinder with 1/16" thick abrasive metal cutting disks); I also have an upright metal cutting bandsaw which I converted from a 14" wood cutting saw (Grizzly), with a jack shaft and stepped pulleys to reduce blade speed. I use a 1/4" bi-metal blade, which cuts slowly but surely, and can make fairly tight radiuses. I use this tool, on many projects. Others might use a plasma cutter or acetylene torch. And of course you'd need the usual drill press, wrenches, grinder, taps and dies, etc. Though I did quite a bit of welding, if you had a well thought out plan, very little welding would be needed. When you're making it up as you go, as I did, expect a lot of false starts and blind alleys.

This took me from 10 to 15 days, and a lot of frustration. Was it worth it? For me, yes, because I like my old Uni, and I like the challenge in something that "can't be done," though admittedly there were moments when I wondered why I was torturing myself so. If you have a machine shop, you can make a much more elegant riving knife mechanism than mine, but I think mine works as well as any.

As for the knife itself, I found a one foot-square piece of 14 gauge plate, which seems to be a perfect fit for the Freud Diablo TK blade. If I decide to use a standard kerf blade, I'll need to use 11 or 12 gauge. A good way to determine the right thickness is to cut a kerf in a piece of hardwood, and take it along with you to the steel yard. If it fits over the plate without binding, you're good to go. The knife is held on with two 1/4" studs, spacers, washers, and nylock nuts (don't want that thing loosening up). The slot in the knife is open at the bottom to make putting in and taking out easier. I decided instant removal and installation weren't that important to me, at least for now. It doesn't require removal to do blind cuts.

I've been having a heck of a time with photobucket, being a newbie at this sort of thing. I fear the photos may be cut off, and don't know whether the text will be included or intact.


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## BigAl98 (Jan 29, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Simply beautiful


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Thanks for your kind comment. If I can get squared away on photobucket, I'll redo the photos and captions that were supposed to go with them.

I started to rip a piece of 3/4" oak the other day, and it had hardly advanced beyond the blade before I ran into resistance. Sure enough, the wood had a lot of locked in stresses, and it had closed up on the riving knife. It was really reassuring to have that thing work exactly as it should.


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## Nicky (Mar 13, 2007)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I get it. The pics are good enough.

Good write-up. This is an elegant solution. I've got to try this.

I appreciate you taking the time to share. The blade guard/splitter was removed a few days after I purchased my saw because it was too cumbersome to use. I do use an aftermarket splitter but your design is far more robust.

Thank you for sharing.


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## Cosmicsniper (Oct 2, 2009)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Love it, my man!!! Thanks for the effort and thorough description of your thought processes in this project. I've strongly considered a DIY riving knife for quite a while now for my unisaw. This is a really nice solution!


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


If anybody wants to try this, I'd be glad to answer any questions you might have. One part I seem to have overlooked is mounting of the actuating arm. You can see well enough how it bolts to a tab welded on to the forearm. The other end is bolted to a 1X1 angle iron, which in turn bolts on where the dust diverter (don't know Delta's name for it) attaches. There are two 5/16-18 holes there, and the arm pivots from about the middle of that. I made the 5/16" bolt holes oblong, in order to make any needed vertical adjustments by tapping up or down. The way I determined where that pivot point should be was to measure distance from the tab on the forearm to the front part of the trunnion. By measuring from two positions-fully raised and fully retracted-I could find the spot where the distances were equal.

I had to sacrifice part of the dust diverter where it came up against the base plate, but was able to save the lower part where it protects the blade elevation worm. Also kept the side opposite the blade intact. Had to shorten the spacers between the deflector and the trunnion by 1/8", the thickness of the angle iron.

Also note that I lowered the very end (1") of the forearm by about 3/8", as otherwise the mounting studs clashed with the ZCI throat plate at 45 deg. when in fully raised position.

In case anyone is wondering, it is fully my intention that anybody is welcome to borrow any ideas from this that they might find useful.


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## DocSavage45 (Aug 14, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Well done,

My "but" is I would have to aquire some metal cutting tools? The Bork might be simpler for me and my ol grizzly bear. LOL!

Nice write up!


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


You can get a 4 1/2" angle grinder for less than $20 from HF. The cutting disks are cheap and expendable-maybe a couple bucks each (I just charge them at my local hardware store, and don't pay much attention). As for the cuts I do with the bandsaw, some of them could be done with the angle grinder, but you also might be able to get a machine shop to cut them out for not much $. I used 1/4" plate for the base plate and the forearm, not for strength but rigidity; also because you can get a reasonable number of threads when you tap a hole. Taps and dies are cheap also, either as sets or individually (you'd only need 5/16-18 and 1/4-20). The actuating arm or bar is 16 gauge (a.k.a. 1/16") because that is plenty rigid and strong for the application.

The materials for this are not at all expensive. I doubt if you'd go much over $50 for everything, probably less.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


One more clarification. In my original post I said I fitted the base plate before cutting the 2 1/2" hole that fits over the arbor flange. Of course that's impossible. The hole has to be cut first, then you slip the plate over the flange before determining where the 3 bolts are going to go. (I actually did do it originally the wrong way, which proved to be the hard way; no need for anybody else to make the same blunder). And it's easiest to start with mockups using moderately stiff cardboard, which are fitted and then used as a template.

Oh, another tip: it's really hard to see pencil marks or even Sharpie marks on steel, especially in bad light. So I get full-sheet (8 1/2"X 11") Pres-a-Ply labels, cut them to the size or shape I need, apply them to the steel, and draw my cutlines on that. The only problem is the stuff is very sticky, and a PITA to get off. Next time I'm going to try some "repositionable" labels, which hopefully won't be so tenacious.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Well, I am figuring out how to do this. Imported directly from iPhoto, no help from photobucket.









Showing the spacers on lefrt; forearm position with blade raised. Slot in forearm was from an aborted trial configuration. Ignore









Forearm position with blade retracted.









Closeup on slots and studs. Extra holes were a blunder. Protrusion at bottom is where actuating arm attaches
.








Actuating arm. Curved shape is to let it go under the pivot elbow. Angle iron bolts on where dust deflector attaches (behind the dust deflector).









Holes in the arbor casting web. Threaded with 5/16-18 tap.









The assembly as it will be mounted (right tilt saw). Studs for RK on the left (1/4-20 thread)









Actuating arm comes out from behind vestige of dust deflector.









Another view. Gap at top of elbow pivot provides clearance for ZCI, and allows arbor wrench to be used for blade changing. One the Unisaw's features I really like.









Another view









Blade and RK at intermediate height.


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## DocSavage45 (Aug 14, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Lookin good!

Just got my grizzly 1023sl cleaned up. Have to put in 220 and go slow as I had a 3hp 10' craftsman before mama bear. I knew the parts of my craftsman and I will be figuring out the bear. Probably similr to the unisaw, but I don't know until I get more involved in the mechanics and handling of the saw.

Until then I'll keep watching?


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## toolie (Mar 16, 2011)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


that's a really excellent job of metal fabrication. is there any chance for a brief video of the RK in actions, being elevated and bevelled, so the action of the added parts can be viewed in motion?


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Actually, a lot of my parts appear to have been shaped with a hatchet (if there were a metal working hatchet). That's because I was making it up as I went along. Tends to lead to randomly shaped parts.

I'll see what I can do about a video. Thanks for the suggestion.


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## Grandpa (Jan 28, 2011)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Great job on this. Thanks for sharing.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


These are supposed to be videos. But I don't know whether they will open as such. Another bump on the learning curve for runswithscissors.

In regard to cutting metal: I forgot to mention the jig/sabre/bayonet saw as a useful tool for this. In cutting the 1/4" wide slots, typical blades are too wide. Just grind the backs of these down so they will fit in the 1/4" hole. In 1/8" inch steel, they will cut reasonably quickly. In 1/4" it will be slow going, but doable. Oh, if your saw has an orbital mode, set it on 0. An orbiting blade will make it difficult to saw metal. Guess how I figured this out.

!https://s3.amazonaws.
com/ljimg/mj9inap.jpg!


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## DocSavage45 (Aug 14, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Try again…LOL! Learning curve on everything.


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## JasonWhite (Mar 4, 2009)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Got any videos of this thing in action?

- Jason


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


For anyone coming across this old blog, I have a few corrections and modifications:

1. I used 3/16" plate, not 1/4". Quarter inch is too thick, and will interfere with the blade. 3/16" is plenty stiff for the job.

2. I originally said I used 16 gauge (1/16") for the actuating arm, but actually it was 1/8". I think you need the extra stiffness.

3. Though I used a 2 1/2" hole saw for the fits over the blade flange, 2 5/8" is better.

4. The arced slots should be in the articulating arm rather than the base plate. Works better in every way.


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## Oxidd1979 (Mar 15, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Wow incredible! This has been done awhile ago, and still today when you search for a unisaw retrofit riving knive, pretty much everywhere people say "it's impossible".

I don't understand how come not a single company came out with a kit! You should fabricate the brackets/arm and sell them with a pattern for the drilling/taping. I would pay a good chunk of $$$ for that!


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I've partnered up with Lee Styron of the Leeway Shark Guard to develop this into marketable product. But we seem to be stalled right now with no movement (as far as I know), as Lee has a lot on his plate, enlarging his operation and upgrading his machinery. You might hurry things along by telling him (via his website) how urgently you need the riving knife.

I've been contemplating doing something like you suggest. The spectrum could run all the way from a finished, reeady-to-install device, to drawings to let people fabricate their own. Your suggestion to make up the basic parts and let the customer do the drilling, tapping, etc. is another possibility. I welded up the holder for the riving knife itself (different from what you see in the photos), and like it because it is adjustable (which I think is necessary) and seems very solid, with no chance of the knife coming loose and causing an accident. Lee has a different idea in mind for that part, but I haven't seen any details yet. I have a pretty good notion what he plans, but don't know how he addresses the adjustability issue.

One approach I've contemplated is to offer a kit in several optional stages: (1)just plans and drawings; (2) base plate, articulating arm, and actuating arm, with no holes drilled or tapped, and leaving the welding of the blade mount up to the purchaser, or letting users work out their own idea.

There's also been an evolutionary process in the mounting of the base plate to the saw arbor. The latest (and best so far) uses a piece of steel tubing of about 2 3/16" O.D. The only tubing I've found of that size is 2" EMT (thin wall electrical conduit). The tubing is about 2" long and has 2 vertical slots (not going all the way down) to accommodate a 5/16" toggle bolt, and is welded onto the baseplate. This tubing slides into the big hole in the arbor web. The toggle (guided by the 1/2" slots) is then tightened to hold the base plate in position. Three 5/16" tapped holes go around outside the tubing to accommodate allen screws and lock nuts for adjusting the baseplate. Two of these adjusters can be seen in the top photo. This is better than the original design in that it requires no drilling and tapping into the arbor web, which is an awkward and difficult process. It may or may not require a slight enlarging or smoothing of the arbor hole. A 1 1/2" spindle sander in a right angle drill works well for this.


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## Oxidd1979 (Mar 15, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Oh wow, very exited about this!!! I like your idea of the toggle bolt.

I don't have much in metalworking tools/skills, so a bolt-on kit would be perfect!!! You could sell that for alot of $$$!!!


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Oxxid: Just out of curiosity, I'm wondering how you define "a lot of $$$" The BORK (I assume you're aware of it-if not, you should check it out at the Bork Store's website) sells for $150, including shipping. The current model of the BORK is made from stainless steel.

I make mine out of mild steel. Lee Styron has said he would powder coat the ones he plans to sell, but I would not do so if I decide to sell them. Lee has talked abut a price somewhere between $150 and $200.

I'm also thinking it would be good to include both 14 gauge and 12 gauge knives for thin kerf and standard kerf blades-or include one, with the other as an additional option.


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## Oxidd1979 (Mar 15, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


More than the Bork for sure, since the conception looks far more superior and looks safer to use since the knife is firmly attached compared to the Bork.

I didnt check, but is there any saw on the market that come with no riving knife and has the option to add one for a price? Maybe that would be a good price to look at.

I don't feel like selling my Unisaw and get a new one just for the knife, and having to change I would go for a SawStop, but for 150,200, heck even 300$, I think I would buy that.


----------



## b67mack (Jul 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Has runwithsissors [and company] been able to produce a kit that i can purchase?


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Leeway Workshops (aka maker of the "Shark Guard") seems to have lost interest in developing it. I'm not sure why. I am still playing around with various tweaks to the design, but it works very well in its most recent iteration. I plan to make up a small run of them, partly to test the market and also to see how difficult or easy it is for buyers to install. I'll probably put out a notice on LJ to let people know its ready for trial. But I can't promise when that's going to happen.

Fact is, I really don't want to go into manufacturing, though I have put quite a bit of thought into acquiring and making parts so that a small production run could be pretty efficient.


----------



## Grandpa (Jan 28, 2011)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


This is the most difficult part of the development. The Irwin Quik Grip clamp took something like 7 years to get marketed after the first design and prototype were complete. I have read some interesting stories about this very problem. You really want someone to take it and market it and give you a share of the royalty. I would buy one. Let me know when you are ready.


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## TheFridge (May 1, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


You are a G. Think I might give it a shot.


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


G?


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## b67mack (Jul 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


How about just selling some of the more complicated parts - not the whole kit. Would that be ez and limit liability?

I am ready to purchase what ever your willing to sell - if no = I am selling the Unisaw and buying a new Powermatic


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## b67mack (Jul 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


G ?


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## Grandpa (Jan 28, 2011)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


G = Genius??? Don't know but a guess


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## b67mack (Jul 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Since I can't bring myself to sell the Unisaw I replaced the arbor bearings - tuned it up and made several stationary smaller splitters -plus refurbished the stock splitter - now its on and off quick. 
I want a bigger band saw more than a new table saw, but a modern riving knife still would be nice


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## TheFridge (May 1, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Gangsta


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## RonTanc (Oct 18, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


runswithscissors - I applaud your effort to fabricate a functioning riving knife. I purchased a new Grizzly 1023 just before riving became mandatory. Like most, the furnished safety guide came off; more dangerous than its worth. Instead I mounted a fabricated splitter where the guide mounted, so it tilts with the saw blade.
I used a 1/8" inch piece of aluminum and shaved it down, using my router table, to the thickness of my saw kerf. I'm satisfied with the performance; it does a good job keeping the cutoff from contacting the blade.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I've been wondering if the design would work with a G 1023. I believe the arbor casting is identical to the Unisaw, but I don't know about the attachment point for the actuating arm. On the Uni, there is a dust deflector partially wrapped around the blade. This is held in place with two 5/16" bolts with spacers about 1 1/4" long or so. I use the bolt holes to attach the actuating arm mount (a 1" angle iron). Because the riving knife takes up a lot of room, much of the dust deflector has to be sacrificed. Without this feature, those bolt holes would have to be drilled and tapped-possible, but it wouldn't be much fun.

Your setup sounds like the next best thing. The advantage of the riving knife is that it not only goes up and down with the blade (making blind cuts straightforward), but also always stays close to the blade, making it less likely that a chunk of wood could pivot into the blade and cause a kickback.

I know there are plenty of G1023s around. I just need to find somebody to let me look at theirs.

I have never owned a TS with a blade guard. Though I did buy a new Rockwell contractor's saw 40-some years ago, which probably came with a blade guard, I never had it on the saw. Never missed it.


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## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


runswithscissors: If you are still interested in doing something with the Riving Knife retro-fit, send me a message (since I am new, I can't PM you until I make 5 posts…). I have been looking for something for my Delta Unisaw - more than just a splitter. I think I might be in a position to help.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I'm having my local steel fabricator cut out the basic components right now. Should have them early next week. Then I have to do some drilling, tapping, welding, and assembling before I can start offering them. Shouldn't be too long, except I have a lot coming down right now so I might not have anything until January. I'm making up 15 of them. They'll be offered on a first come first serve basis. I'm guessing I'm going to ask $150, but can't be sure until I've added up all costs.

What do you mean by being "in a position to help"?


----------



## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I did not intend to post anything blowing my own horn, but since you asked…. I retired from the Consumer Products industry after several decades working for Fortune 500 companies in strategic planning, marketing, and business development.

I have started my own business in retirement (based on my love for woodworking but not exclusive to same), as an outsource company for other businesses as well as direct to the end user. I use a number of CNC machines for a lot of what I do, as well as traditional woodworking equipment. I am familiar with CAD/CAM and what I cannot produce, I have people I work with locally who can, be it laser, plasma, waterjet, etc.

My son also assists me from time to time (outside his day job), using his skills in 3D Solid Modeling and Design, to create and produce working models of more complex products that I cannot design myself. We use these models and CAD files either directly or through other partners, to produce the end products.

My initial goal was to add a Riving Knife to my 10 year old Unisaw. It looked like you had a very viable product. I was disappointed to read that your previous attempt at production with another company did not materialize. I reached out to you in an attempt the see if it could be revitalized and whether we could assist you in any capacity; from a final product to just a set of comprehensive plans or individual components for others to use.

I am encouraged that you are moving forward and look forward to seeing the final product, as my initial desire is the same as so many other Unisaw owners: A Riving Knife retro-fit that actually works as a riving knife without caveat or limitations. Please add me to your notification list when you have finished products and pricing in place. Photographs and concise instructions will also prove invaluable in making a purchasing decision as well as creating a satisfactory end-user experience.

Best regards,
Dave


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## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Clearly, DELTA is more interested in selling new saws to existing customers, rather than developing an improved retro-fit kit as exemplified by their response to the following question:

*Do you offer conversion kits to install a Riving Knife System on an existing Table Saw?*

"No, we do not offer any riving knife conversion kits, and do not plan to.:

"A Riving Knife System requires the table saw mechanism be designed to utilize a riving knife. None of our existing table saws are designed to accept a riving knife and the changes required to convert a saw would be extensive. Conversion kits are not a practical solution for this situation."

So, a need exists, demand is there, and someone will eventually fill the void.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I am fairly confident that the Grizzly 1023 has the same arbor casting as the Unisaw. I have a friend with one, and plan to check it out at earliest convenience. The Unisaw's "dust diverter" is also part of the setup, because its mounting point is where the actuating arm has to attach, and I need to check that out as well.

If it can fit on the 1023, that opens up more of a market. And there might be other clones of the Unisaw too. I have toyed with the idea of approaching Grizzly with this thing (I live in Bellingham, where Grizzly's corporate HQ is located).

My analysis of the situation goes something like this: If manufacturers were to offer a riving knife conversion kit, that would interfere with their desire to sell more new saws. On the other hand, if somebody can only have a riving knife by buying a new saw, there is no guarantee that that person will buy the same brand-a Powermatic to replace the Grizzly, for example. Sort of a dilemma. On the other hand (again), if a third party is making these available, isn't that going to cut into the market for new saws? But if that's so, wouldn't it be to their advantage to get a piece of that market, by offering their own version (or mine)?

In my imagination, these are the sorts of arguments that might get kicked around in a boardroom.

After writing the above, I realized that you had a 2 part message, so I just read the first part now. My situation is that I prefer not to venture into manufacturing, though I have worked out sources for components and ways to fabricate the parts I can't buy. I am open to arrangements with other people, such as yourself. It has been suggested by others that I make plans available, which would possible. Right now I can't make professional looking plans because I don't have CAD nor the skills to use it. I do wonder about "Sketchup," and whether it might work for that.

At some point, I would love to sell the whole kit and kaboodle to someone who could take development to the next phase. I thought that was what I had with Leeway Workshops.

I think it's interesting to compare the situation to the BORK. As far as I know, he has a fairly small market (last I heard, he'd sold over 200 of them, but that was a while ago), and I assume he has not found anyone wanting to take over the operation for full scale production. In other words, the BORK is still largely handmade.

I don't have any problem with self horn blowing, if somebody has a real horn.


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## DocSavage45 (Aug 14, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Great read guys! I looked at the Bork soon after I purchased my 1023 grizzly. Been awhile. I think if you all could get together and come up with an installation for dummies manual? People such as myself with enough mechanical knowledge to be considered dangerous might have a chance. LOL!

If there have only been 200 sold total? it would be problematic regarding time and money to get this semi commercial?


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## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


BORK, if I recall correctly, still has some issues with the knife extending above the blade, difficult to install and adjust, etc. Maybe he has corrected that. I haven't checked lately. Besides, who wants to install a Riving Knife that uses a hose clamp to connect to saw? Talk about a liability nightmare. I know he supplied a U-Bolt Clamp, but it was too large and people resorted to hose clamps. There are some scary videos on YouTube showing what people will do to "correct" a design that wasn't well thought out in the first place.

Manufacturers will usually not follow a particular production methodology, until forced to for some specific reason, usually involving fiscal inducements, either negatively or positively. SawStop tried for many years to get the Government to "encourage" all table saw manufacturers to incorporate their proprietary, patented technology into all the saw they produce. The manufacturers argued that it was cost prohibitive to do so and eventually SawStop gave up. SawStop was invented by a patent attorney and he had the personal skill-set to run with that ball for a long time. Ultimately, they decided to produce the saws themselves. Their offices are not far from where we are.

The same approach was taken when seat belts were first introduced into the automotive arena. Great resistance was met. It took a long time but largely due to the hue and cry over deaths in car accidents, they eventually became mandatory equipment.

Saw manufacturers recognize the desire/need for what European's have enjoyed for a long time; Riving Knife based saws. However, they also recognize that retro-fit's will erode future saw sales, so it will ultimately fall to the individual entrepreneur to recognize and meet that demand/need. A potential outcome could be a saw manufacturer buying out a successful retro-fit company… for a number of reasons, but most likely to eliminate competition and enhance saw sales. They are the big dog and they don't play fair. If a company succeeds, rest assured the manufacturers will circle the wagons and bring all guns to bear on the upstart. Their focus will be on "safety and liability concerns" that will need myriad government approved test results, etc., all of which no start up can afford.

So the end-game will be to develop a retro-fit product/plans/components and get what market share is available before the manufacturers sit up and take notice, then deal with whatever happens appropriately. Worse case scenario, shut the upstart down early on because they cannot afford to play the game. Best case scenario, the upstart operates for a protracted amount of time and makes some good money in the process and provides a product/service that is in demand.

This guy was on to something but he went dark a couple years ago, or so. No one has heard anything since. (Riving Knife )

Some will say that there is the risk of being sued by someone who claims they were injured using the product. And they are right. There is always that possibility no matter what you do by way of Hold Harmless Agreements, Liability Waivers, etc. There will always be a legal beagle somewhere wanting to make his bones in a lawsuit.

We use a number of CAD programs, some costing over $15K. Doing engineering quality plans is not an issue.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I'm not deluding myself that this thing could make me rich. But I wouldn't mind making a few bucks off of it. Amongst the scenarios I have envisioned, one is to do nothing with it and let it go, and not suffer a broken heart.

But then I think of the guys who want a riving knife without having to buy a new saw.


----------



## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I believe there is ample time and opportunity to provide a quality product, at a fair price, to people who have been looking for this solution. It would take some time before any manufacturers would feel a "need" to respond with a credible threat to your business.

I would recommend you proceed with a well thought out strategy which accomplishes what you want to do in terms of providing the quality product you envision. It should encompass all aspects of what you want to provide, from a plug-n-play product, components, or plans. Refine your design to whatever level you believe it should be in order to justify the price and maximize buyer satisfaction across all levels. Develop your pricing models and marketing plan and execute them.

The only reason you would experience remorse, is if you don't do it. If I can assist in any capacity, feel free to reach out.


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## Deepriver (Jan 29, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


If you build it, I will buy one. 
If you are thinking about it, I will send cash up front.
I think a riving knife is the single most reliable safety device a table saw can have, and my Unisaw does not have one yet.


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I have the main parts cut out for 15 of them. Still have to fab a few parts, drill and tap some holes, and stick 'em all together. But I've got a lot on my plate right now, and it probably will be a few weeks. When I have them ready, I will announce on LJ forums.

I've been dithering about the knife itself. I'm trying to find out whether saws nowadays come with both thick and thin knives, or just the thin knife (you can't use a thick knife with a think kerf blade). I'm going to check with Grizzly tomorrow. It seems like I've read that SawStop comes with a TK knife, as it shouldn't be a problem with a thick kerf blade. What do you think? I can't decide whether it would be worthwhile to offer both knives, or to give the buyer a choice, or to offer one as an added option.

I haven't added up all costs yet. Of course I want to make some profit or pay myself a reasonable wage. I'm thinking about $160 for a price. I'd also like your reaction to that.


----------



## Deepriver (Jan 29, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I almost always use thin kerf blades, so one knife is fine.
$160 is fair- comparable to both the shark guard and the BORK (and about the price of the OEM assembly).
Please put me on the list.


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


You're at the top of the list.


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## b67mack (Jul 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


as I posted 6 months ago
Just get me the more complicated pcs and Ill do the rest
or at least put me at number 2 on the list


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Okay. I could put together a kit. I'd need to write up instructions, though you could figure out some details yourself.


----------



## b67mack (Jul 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Perfect!


----------



## Deepriver (Jan 29, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I suspect most of the folks who would be in the market for this thing are probably okay with a 'some assembly required' type kit.


----------



## Sierras (Oct 24, 2010)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Just stumbled on the thread. Great read! Last week I was searching the web for a riving knife for my 2000 Unisaw and not findling anything that looked worthwhile. This seems to have great possibilities. I'm interested in a standard kerf with the possibility of adding a thin kerf. 
Put me on the list!


----------



## Grandpa (Jan 28, 2011)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Put me on the list. Why don't you offer this with buyer's choice of thick or thin kerf. The other knife (thick or thin) for $XX additional.


----------



## kevmn (Nov 27, 2007)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Very impressive. Good work!

I would be interested in one with a standard kerf riving knife.

This post is very interesting. A few years ago I started prototyping my own ideas for a retrofit riving knife for the Unisaw after reading some postings on other forums. Needless to say life with four small children prevented much progress. I did talk with the owner of a CNC shop to see if they had any interest and they would not touch it because of fears of liability.


----------



## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...





> I did talk with the owner of a CNC shop to see if they had any interest and they would not touch it because of fears of liability.
> - kevmn


Shops who actually manufacture ready to use components could find themselves in a liability issue for manufacturers defects. However, if they were just cutting parts to specifications, it's a moot point.

Cutting steel parts on a CNC Laser system is affordable, accurate and efficient. Barring metal fatigue in the steel, the greatest risk is operator error and that cannot be prevented by the CNC Shop, manufacturer or reseller.

In the end, it doesn't matter what a company does to protect itself against liability; someone sooner or later may try to make a buck from their own stupidity. That's what Liability Insurance is for.


----------



## larsof54 (Jul 15, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I would also like to be on the list. I have a mid-seventies unisaw that begs for a RK.


----------



## olrac (Feb 2, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Did you happen to transfer these shapes to paper? That would save major design time for us. I'd be happy to pay for them. Great design, the best I've seen.


----------



## olrac (Feb 2, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Sorry, I guess the better question would be, could you transfer them to paper. Then they could be printed out full size. Again I'd be happy to pay you for them. I ask this as I am assuming you have a right tilt and I would probably have to adapt this for left tilt(maybe just a mirror image?) If yours is a left tilt or you could make one for a left tilt, sign me up.


----------



## Surfer50 (Mar 28, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Add me too. Either plans or finished product.. Seems to me at least 200 for finished product with one knife is more than reasonable Thanks


----------



## Deepriver (Jan 29, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


The weather is getting warmer, and I'm starting to itch for a bit more shop time. I'd love to have that riving knife installed. Any news?


----------



## buster09841 (Nov 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


runswithscissors -

I sent you a PM a few days back, hadn't heard anything and wanted to see if you got it or saw it?!

thanks!!


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Sorry for the delay. I have had a lot on my plate lately, and will get back to the riving knife as soon as I can. I'll let you know when it's ready.

Dave


----------



## buster09841 (Nov 7, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


sounds good Dave!

I really would like this to add to my Unisaw. if it would help speed things up I have money ready 

PM me back then.

Brian


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## olrac (Feb 2, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Is there any chance you might have any ready to go for a left tilt unisaw?


----------



## Deepriver (Jan 29, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Still hoping. Any updates?


----------



## PCDub (Sep 24, 2017)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Wonder whatever happened to this…


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I will have a few of these to ship out within the next couple of weeks. If you want to see what installation entails, PM me for a copy of installation instructions (rough draft, that is). Will help you decide if the RK is right for your saw (and you).

Price will be $150 with one knife, either for standard kerf or thin kerf. If you want both knives, that will cost another $15. Shipping costs TBD.

If you use both full kerf and thin kerf blades, but want only one knife, I recommend the 14 gauge knife, as it will work fine with full kerf blades. Full kerf blades will not work properly with think kerf knives. Full kerf knives are 12 gauge.


----------



## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Please check your PMs. I never received a reply to my first PM and do not know of any other way to contact you. If your kit fits my unisaw then consider one setup sold with both size knives.


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Sorry. Have to confess I don't know how to access pms (embarrassing). Email me at <davidpeebles>. I did respond to one message in the thread a week or so ago, but maybe it didn't get to you.

Dave


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## Deepriver (Jan 29, 2015)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Hi David- Also very interested, (and also tried a PM) but I don't see your whole email address. Can you please provide the whole email, or send a note to my email: paulchiasson (AT) gmail (DOT) com.
thanks, Paul.


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


My email: <davidpeebles>


----------



## TheFridge (May 1, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


@google.com @gmail.com @hotmail.com @yahoo.com?


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## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I would be interested in a set of the instructions as well, to see if it would work for my Unisaw. Is it possible to post a PDF attachment?


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Yes. Don't think it is pdf though.

Installing the Riving Knife on a Unisaw

This riving knife is designed to fit on a pre-2009 Unisaw (i.e. one lacking a riving knife). This is for 10" right tilt saws.

What you have to give up: The existing splitter and/or blade guard, and its mounting block at the back of the arbor. Also the blade shroud (dust diverter) at the front of the blade. If you want a bade guard, I suggest one of the over arm types. It is possible to save part of the dust diverter, but the part that will conflict with the RK mechanism will need to be cut away. The remaining blade shroud can be used, but a lot of its effectiveness at deflecting the dust downward will be lost. I originally did this on my own saw, but gave it up as not worthwhile. You also will not be able to use the original throat plate, as the little "bridge" that joins both sides of the slot will interfere with the RK. Make a zero clearance throat plate instead.

The riving knife consists of 3 main parts.

1. The base plate. This serves as the mount for the articulating RK arm and also as a pivot point for the arm.

2. The articulating arm itself, which holds the actual knife.

3. the actuating link, which bolts at the front of the saw, using the same 5/16"-18 holes by which the dust shroud was mounted.

Tools you will need: 13mm or 1/2" socket wrench. A ratcheting 3/8" driver (or 3/8" flex wrench), plus an extension bar from 4" to 6" long. You will also need a combination wrench in this size. Also an 11mm (3/8" socket and/or combination wrench. And a -- allen wrench for the height adjusting screw. I also highly recommend a small headlamp, as this allows you to see while leaving both hands free.

The special extra long ball-head allen wrench for adjusting the knife after installation is provided.

PROCEDURE

Step One. Unplug the saw.

Step 2: remove the blade.

Step 3. Remove the blade shroud/dust diverter. This is held in place by two 5/16"-18 bolts about 2 inches long. Set the bolts aside, as they are too long to use with the actuating link.

Step 4. Remove the mounting block for the splitter/blade guard.

Step 5. Install the base plate. Study how this works: note how the wing bolt is pushed (without twisting) through the 2+ inch pipe. Practice this so that you can see how the wings fold out through the slots. Before tightening the bolt, be sure to pull the bolt out as far as possible. The wings must be folded up inside the pipe, and lined up with the slots. As you start tightening the bolt, be sure the bolt stays pulled out and that the wings stay in the notches.

If the wings fail to engage the slot, you will have to remove the wings by backing the bolt out all the way. After fishing the wings out from the bottom of your saw, start over again.

Note: by lowering the arbor, it may be possible to insert your hand behind it far enough to deal with any misalignment problem. Still better to just start over, though.

Tighten the wing bolt to snug the base plate up against the arbor casting. Don't over tighten. It will be adjusted later. Also, adjust the vertical alignment of the base plate with the adjusting screw at the top. Try to have the big hole in the base plate be concentric with the blade flange. This is not critical, but get it as close by eye as you can. The main thing is to avoid any interference between the parts. The vertical adjustment is important to keep the RK from dropping too much and contacting the blade.

Step 6. Bolt the articulating link angle iron to the arbor, using the holes where the dust shroud was attached. These bolts should be no more than 3/4" long, to avoid interfering with the trunnion.

Step 7. Bolt the articulating link to the tab welded onto the bottom of the articulating arm. Crank the arbor up and down several times to make sure everything moves smoothly. Adjust the link plate up or down to adjust the movement of the articulating arm. Move it down to raise the arm higher.

Step 8. Install the riving knife, making sure it goes between the steel plates.

Step 9. Reinstall the blade. Rotate it several times to make sure there is no rubbing or contact with any of the RK parts.

Step 10. Align the RK with the blade. If the blade is thicker than the RK, make them flush on the side toward the TS fence.

To adjust the RK, use the 12" long ball-end allen wrench. To do this you will need to remove the motor cover (if any). Insert the allen wrench from the left side of the saw (left as you are standing behind the saw) into the very top corner between table and the side of the saw cabinet. If you peer through here, you will see the RK adjusting screws. If you do have a motor cover, you may want to cut off the corner of it, or drill a 1/2" or larger hole in the corner. A step drill works best for enlarging holes in sheet metal.

Do the RK adjustment by alternately tightening or loosening the RK clamping knob. Use a straight edge to help align the blade with the RK. Be sure it is aligned both at top and bottom. You may have to lower the arbor slightly to engage the cap screws properly.

Step 11. Make a zero clearance throat plate. First, remove the RK. Set a new throat plate into the saw table (if you don't already have one), Clamp a board over the plate to prevent it rising when you raise the blade (slowly), cutting a new blade slot. Raise the blade to its full height.

Lower the blade and remove the ZCI. Put the old throat insert back in place. Turn the new ZCI upside down and end-for-end. crank the blade up, and slip the ZCI over the blade. Now move the fence over so that it touches the ZCI. Start the saw, and carefully complete the cut. Stop abut 1/2" before cutting all the way. Remove the old throat plate, and insert the RK. Install the new ZCI and make sure the RK can rise and fall without binding.

You can also extend the slot with a handsaw.

Step 12. Adjustments. Lay a straightedge along the top of the blade and the RK. The RK should be a little lower-say, 1/8" to 1/4"- than the blade. Grind or cut away any excess height from the RK.

NEW TOPIC. Bevel sawing. You can make a special ZCI for bevel cutting, but it's a smoky, frustrating thing to do-unless you want only the 45 deg. option. And it won't be a zero clearance insert, because of the angle of the blade as it comes through. t's probably best to remove the RK and use the original throat insert for beveling.

If you decide to use the old throat plate when beveling, you can make a splitter to replace the riving knife. A drawing shows what this can look like.


----------



## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Ok, so I have a Unisaw from around 204. It's a 36-L31X (left tilt). My question, besides the obvious regarding the left tilt, is this: Is there still room for the arbor wrench on the ardor to hold the spindle during blade changes? I suspect there is, but it's not real clear in the photos.

Secondly, your first post initially referenced drilling holes with a right angle drill. . . but your last post (instructions) didn't mention it. Has that need been eliminated?

Lastly, I suspect that a left tilt isn't a deal breaker, but just a matter of flipping (mirroring) certain components. Would you share that assumption?

it sounds like you are in or around Bellingham, Washington, is that correct? I am up there from time to time to visit my son and will be in the area in June for his wedding. What are the chances of getting together for a few minutes?

Regards,

Dave


----------



## shawn_s (Oct 27, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I'm interested too. I sent a PM, but if you still can't get to them, my question is will you ship to Canada? My email is: [email protected]

Shawn


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Pogo (Dave): My RK is for right tilt only, sorry. But yes, the gap at the top of the rotating parts is there not only to clear the underside of the table, but also to allow use of the arbor wrench (I actually had to make my own out of a piece of plate, but the original would probably work too).

And there is no longer a need to drill any holes. I redesigned the base plate for that (and had to discard a pile of the old ones-my loss).

Since I don't know what the arbor and trunnion look like on a left tilt, I can't say whether a mirror image would work. Perhaps you can see enough in the old photos to make a guess at that yourself?

Yes, I could meet with you in June. But that means I have to clean up my shop, darn it.


----------



## kevmn (Nov 27, 2007)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Hi, I have a right tilt Unisaw and I would be interested in your riving knife. I have been following this post for quite a while. It looks like you at a point to produce your solution. Can I place an order? I can not send a PM at this time because I have not posted enough so let me know if I am able to get on "the list". Thanks!


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Yes, you may. And I would suggest to others making inquiries that you include your email address to simplify communication.


----------



## kevmn (Nov 27, 2007)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Great. Thank you for a quick response.

My email: [email protected]

Thank you!


----------



## PogoCornEater (Dec 12, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Great! I will keep touch. When the date gets closer, we can try to coordinate something.

Thanks again,

Dave ([email protected](dot)com)


----------



## danpat (Jan 24, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Dave - if you've still got any left, I'm interested - I just scored a right-tilt 36-812 (early 90's) that's missing all the safety gear, your contraption looks like by far the best retrofit option, it's super impressive.

Please add me to your list: [email protected]


----------



## Nick8751 (Jan 25, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Yes I am very interested as well please email me I will take one
[email protected]


----------



## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


USPS flat rate box costs $13.50, to anywhere in continental USA. Same to Canada is $45.95.

Pogocorneater: The cylinder that registers the base plate and locks it in place (goes into the 2+ inch hole) is lightly tacked on, and would by easy to cut off and re weld on the other side. But the knife holder would be another story, as it isn't so easy to move. One possibility would be to send you the articulating arm without the knife holder attached, so you could figure out how to weld it yourself. But as I say, I have no idea whether it would work on a left tilt. If you could send me a photo of your arbor I might be able to advise you better.

Something I forgot to mention in the installation instructions: If the 2+ inch hole in the arbor is a little small for the base plate cylinder, it is easy to ream this out with a 2 inch drum sander in a right angle drill. Use a coarse grit. Cast iron sands very easily, so be careful not to overdo it.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


My comcast. email inbox is totally empty, so I have received no new emails. Comcast reports a big backlog of people seeking help, so I suspect this is some issue with them.

Meanwhile, if anyone needs to get ahold of me, I will check this thread often until the email thing is resolved.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Email problem is resolved. Back in business.

I have sent out one kit so far, but haven't heard back from him. He was possibly going to install it this weekend.


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## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I did get the unit installed this weekend and utilized the saw a bit. I sent an email with all the details. I just sent the email again. I am willing to post here as well but wanted you to review my email before I publicly posted.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Thanks, Brian, I did get your email. If you do post that here, could you also include my response (assuming you got my answering email)?


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## sandv58 (Oct 14, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Brian - I'm also interested in hearing you impressions of the riving knife retrofit.


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## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I am currently on a family vacation. I will write a review of the installation and get some photos when I get back.


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## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


As promised here is me review of the Unisaw Riving Knife Retrofit kit made by runswithscissors , David.

This is a picture of what was in the box upon its arrival. A drawing identifying the pieces, 2 main mechanism components, two bolts, adjustment allen wrench and the riving knife itself. You can see I chose to get both riving knives as they are available in different thicknesses. I printed the instructions that were provided. 









The installation was pretty straight forward. I did run into one issue. In the picture below you will see a shield of sorts, I think it is a dust shield. It was installed in between the saw blade and the front of the saw cabinet. There was no mention of this shield in the instructions. No fault of David. There are too many variables over the course of 50+ years on manufacturing for anyone outside of Delta to know every option. 









I figured if the shield was there it should stay there. The problem is that the bolts that hold on the shield are the same bolts that hold the swing arm part of the riving knife mechanism to the saw. I tried to install both but if you look at the shield, the bolts are right at the 45 bend on the right side of the shield. There is not enough room inside the shield to mount the swing arm bracket. The bolts were also much longer than needed as the shield was mounted on 1.5" spacers. David includes 2 bolts in the package to mount the swing arm mechanism. The ones in the saw are 5/16 but the ones provided were 3/8. A mistake that can be easily rectified, it happens to everyone. Since the bolts I had on hand were too long and the ones provided were the wrong size I just used the long bolts with the spacers in between the swing arm bracket and the bolt head. You can see it in the picture below.









Moving onto the main component of the mechanism, it goes over the hub of the saw arbor and gets secured with toggle bolt. You can see the head of it in the main mechanism in the middle of the flat area on the far right side of this picture. 









I did have a bit of interference when raising the new riving knife. At the back of the throat opening there was a attachment point for what I assume is the stock blade guard. I simply unbolted it as it was not being used anyway. The used saw came without a blade guard.









Now that I had the mechanism installed I needed to adjust the riving knife so it was aligned with the blade. This was a bit of a pia. It was a lot of back and forth. The issue is that you have to make the adjustment to the riving knife from under the table going through the motor door, thsi is where the long allen wrench is used and needed. Then go back up top, tighten the riving knife and check the alignment. More of an inconvenience than anything else but once it is dialed in you are good to go. Both the blade and riving knife atr attached and referenced from the right side thus once the alignment is set it is set. If you go to a thin kerf blade and thin kerf knife they should be in alignment. Same for standard kerf. Back to this in a minute.

Installing and removing the riving knife could not be simpler. A 1/4 turn of the knob is all that is needed. Of course the throat plate needs to be removed to do this but I think that goes without saying.









Here is a view of the riving knife adjustment screws,as viewed though the motor door on the right side of the saw cabinet. A bit of some medium thread lock might be a good idea if you are going to utilize the saw without the knife, say for a dado blade. This way the adjustment screws will not vibrate and cause an out of alignment issue. 


















The alignment, both left and right as well as vertical are all done with 3 set screws. This is looking down from above the table.









Here you can see the alignment of the riving knife when finished. This is a picture from the front of the saw. The riving knife is behind the blade. You can see a bit of the knife above the blade because the riving knife is provided a little tall so the user can grind it down to the proper height.









I have used the saw with the riving knife and it worked as if the knife was not even there, in a good way. No interference with the stock. I will say I was a bit nervous the first time I turned on the saw. I was not sure if I did anything wrong and any high speed flying steel was going to come shooting out at me. LOL. Nothing like that happened. The clearances are tight but not too tight.

One other thing that needs to be done is to modify the throat plate. You need to elongate the hole the saw blade runs in as the riving knife is now behind it. I just used a jig saw. Also, when the blade is at its highest there is a set screw that hits it. A little relieving of the throat plate with a small drill bit is all that is needed. Or just don't go to maximum height. Here are a couple of pictures that show what I am talking about.


















Overall I am very very very happy with this kit. I would buy another in a heart beat if I needed it. A great safety enhancement without question and at such a reasonable cost. With a bit of refinement like paint I think this kit would be great value at twice the cost if not more.

Communication with David was quick and easy. He answered all of my emails. Shipping was fast after payment was made.

If anyone has any questions about anything I will be more than happy to answer whatever I can. If I missed anything just let me know and I will add it.

Here are some more photos. 



























I have a video of it in operation too.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Brian, thanks for the review. I think I did mention in the instructions that you would have to sacrifice the blade dust shroud (under "what you will have to give up"). I tried to save mine by cutting away that part that interferes with the link arm, but what was left didn't seem to be very effective, so I gave it up.

I will look into the other issues you raised and see what I can do about them. I am now including a thin plastic insert in the knife holder which acts like the nylon insert in a nylock nut, to prevent vibration from loosening the adjusting screws. If there is a way I can help you with this, I will. Since the hole pattern for the adjusting screws may vary slightly from one RK to the next (this thing is handmade, remember), it would be ideal if you could send me a paper pattern showing the exact hole locations. Or you could make your own. The plastic from a cottage cheese tub lid would work well. Unfortunately, you would have to remove the kit to install it.

When aligning the knife to the blade, I stand at the back of the saw, insert the long allen wrench under the left (motor side) of the saw with my left hand, and alternately tighten and loosen the knife clamp with my right hand. Goes much quicker that way. It may help to lower the arbor slightly (1/4" to 1/2") while doing this.


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## aliasbane (Dec 27, 2017)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Good to see a good review on this as its like 1 of 3 options i have found.


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## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...





> Brian, thanks for the review. I think I did mention in the instructions that you would have to sacrifice the blade dust shroud (under "what you will have to give up"). I tried to save mine by cutting away that part that interferes with the link arm, but what was left didn t seem to be very effective, so I gave it up.
> 
> I will look into the other issues you raised and see what I can do about them. I am now including a thin plastic insert in the knife holder which acts like the nylon insert in a nylock nut, to prevent vibration from loosening the adjusting screws. If there is a way I can help you with this, I will. Since the hole pattern for the adjusting screws may vary slightly from one RK to the next (this thing is handmade, remember), it would be ideal if you could send me a paper pattern showing the exact hole locations. Or you could make your own. The plastic from a cottage cheese tub lid would work well. Unfortunately, you would have to remove the kit to install it.
> 
> ...


No problem David. I may have missed the part about the dust shroud in my haste to install my new toy. If so I apologize about that. edit: David, I went and reread your original instructions and sure enough you mentioned the shroud in the "What you lose" section. I either missed it or more likely, forgot about that detail. My bad.

As for the knife adjusting bolts, I do not have a need to remove them right now. Maybe we can discuss your solution a bit more in depth via email? Nothing of any immediate concern on my part.

I did not think about adjusting the knife from behind. I would have to remove the motor cover door though as I think it hits the back rail I have. But I see how it would be much easier that way, especially for a lefty.

In spite if these little details you designed a great solution for a safety issue.


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## sandv58 (Oct 14, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Brian - thanks for the great review. One question I have after watching the video is that I noticed that when raising the blade the riving knife seems to hit a couple spots where the knife seems to pause, move slightly backward and then continue. Can you explain this behavior?

Thanks,
Scott


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## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...





> Brian - thanks for the great review. One question I have after watching the video is that I noticed that when raising the blade the riving knife seems to hit a couple spots where the knife seems to pause, move slightly backward and then continue. Can you explain this behavior?
> 
> Thanks,
> Scott
> ...


Scott,
That only happens on the way up, not the way down and only at those specific points. I think it is due to the mechanism being a bit tight. It may smooth out over time. Another option would be to take it apart, find the spot it is binding a bit and grind it a bit smoother. This is all speculation on my part. Maybe David can chime in on this.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I am pretty sure I know what is causing that slight hanging up. The steel supplier I had cut those parts used a plasma cutter, and I fear got those arcing slots a bit uneven in width. I have been filing the inside of those curves to widen the slots slightly in the inner part of the arc. Apparently I didn't file enough on yours. If you decide to deal with that on your own, be sure not to lose the little brass spacer bushings from the machine screws. Also notice that the bottom one has to be ground flush to avoid conflict with the arbor. The other 2 don't matter. At the same time, it wouldn't hurt to apply a bit of paste wax to the mating (rubbing) surfaces.

Were I to make up more of these (which I probably won't), I'd have Cutters, Inc. do them, as they use water jet to cut with, and their work seems much more precise.

Thanks for your patience, Brian.

Dave


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Another thing to try is to apply a little paste wax in those slots, especially the edges. Maybe with a Q-tip. Might remove enough friction to make it a non-issue.

Dave


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


And another thing: There is a sharp corner on the base plate that may be clashing with the nut on little bolt that attaches the link arm with its mounting block. Run your RK up and down to make sure it isn't hitting at that point. I discovered this on my own RK. Easy enough to grind it a bit if necessary, though you probably can't get an angle grinder in there.

Dave


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## GrantA (Jul 19, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Have you used this much? The only thing holding me up, making me think about building my own is the loss of the dust shield. I thought I read somewhere that dust blows out the front of the saw once it's removed. 
Did you use dust collection in the cabinet before /after?

Thanks!
Grant 


> - Macrosill


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Yeah, there is a little dust blows out the front. I have toyed with ideas (in a desultory way) to mitigate that, but it doesn't seem terribly concerning to me now. I did cut away part of the dust diverter early on, to clear the RK mechanism, but it hardly seemed worth while (and didn't work that well).

I do think an overarm dust collection from above the blade might help. In fact I have one, but haven't had time to install it yet.


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## Macrosill (Nov 27, 2016)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...





> Have you used this much? The only thing holding me up, making me think about building my own is the loss of the dust shield. I thought I read somewhere that dust blows out the front of the saw once it s removed.
> Did you use dust collection in the cabinet before /after?
> 
> Thanks!
> ...


Grant,
I have not used it "much" I use the TS rolled out of the garage in the driveway since I do not have any dust collection. Too cold right now. 4 Nor'easters in 3 weeks. I could cut a finger off and probably not feel it. LOL


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## GrantA (Jul 19, 2014)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I have received one of these kits and I'm very pleased with it! My saw has the top and motor removed right now (about to get an overhaul before I put it in service) so I was able to spot a couple issues much more easily than someone with an assembled saw. 
Dave- the toggle bolt should be shortened by at least a quarter inch. Mine made contact with the yoke, preventing full height on the blade. I cut right at 3/8 off of mine and it has plenty of clearance now.
Mine had a little bump in it going up and down as well so I watched it carefully and the culprit was the pivot point at the front, where the arm connects to the angle (where the dust shield used to be). I snugged that bolt a little tighter and that seemed to take out all of the slop. I'm thinking of modifying mine with bushings (brass or bronze) on all the moving points to allow the fasteners to be tightened without binding the motion 
One thing I have to gripe about, and is not a big deal but whenever a bolt is cut shorter please hit the end with a file to help it start into its mating threads. 
Overall, great piece and it gets better -
I have been working with Lee @ sharkguard and he now has a knife to fit Dave's bracket and mount the sharkguard! I'll have the first one soon and will make sure all's well with it. I'll report back here of course

Thanks again Dave!


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Grant: thanks for the report. As for the bushings, I put one where the link joins with the articulating arm, and of course in the three screws that go in the arced slots and let it pivot. Getting those to exactly the right length is problematic, as there will be slop if the bushings are too long, and it will bind up if too short. As for the pivot at the front of the saw, I frankly didn't give it much thought. I figured the nylock snugged up on the bolt would be adequate. If you do want to try bushings, I suggest getting brass tubing of the right diameter. My local hardware store carries it in a variety of IDs and ODs. I don't know of any source for bronze bushings that tiny.

Sorry about the thread ends not being smoothed. I know exactly what you mean. Also thanks for the heads up about the toggle bolt. I will shorten those from now on. That's good news about Sharkguard. I'm a little surprised he would go to the bother over such a small market. I might get one myself.

Dave


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I crawled under my saw and sure enough the bolt was too long. I shortened it to 2 1/2", and I think that is about right. You don't want the bolt too short, as that will let the toggle go all higgledy piggledy, which won't work well.


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## nohuhu (Jun 21, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


David,

Do you have any of these kits left for sale? I just scored an old Grizzly G1023 and am in the process of restoring it. I was studying parts list and pics of Grizzly G0690 to see if I could retrofit new parts from that model but your solution looks so much better. I'd be happy to try fitting your RK system on my new old saw, modifying it if necessary.

Please drop me a line at no <dot> huhu <at> nohuhu <dot> org.

Regards,
Alex.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Alex: Yes, I have a kit available. Don't know whether it will fit the G1023, though it is said that it is a clone of the Unisaw. Maybe best to send me a PM so that we can continue by ordinary email (not sure I understand all of your email address there).

If it should work on yours, that would open up a whole new market, which I have mixed feelings about, as I don't want to go into big time manufacturing.


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## nohuhu (Jun 21, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


David,

Glad to hear you have this stuff. Adding a riving knife to my table saw is one of the topmost priorities on my list, right below dust collection. The saw I use at the moment is old Delta contractor style, with no way to add a riving knife at all.

I don't know if your RK is going to work on a Grizzly but just from looking at the pics there's great similarity in trunnion design between Unisaw and Grizzly so there's a chance RK might fit. If it doesn't I'm open to modifying it if that's possible.

If it absolutely doesn't work then well, at least we'll know for sure. 

Sent you a PM.

Regards,
Alex.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


For those trying to decide whether the riving knife will fit on their saw, here is a photo of the arbor that I used for R & D. The 2+" hole is key, as it locates the mechanism and secures it solidly to the arbor. This is an older one that came from E Bay, and is essentially the same as the one on my personal saw (with slight, minor differences).


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## nohuhu (Jun 21, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


David,

I received the package yesterday. Extremely quick shipping from WA to NorCal, I didn't really expect to get it this soon. Thanks!

Haven't had a chance to take my saw apart yet but tried to fit the part that goes on the arbor, and it seems to fit the arbor, more or less. I can't be 100% sure yet, will try to get more results this weekend, with pics.

One thing that might need some modification is the pivoting arm that holds RK blade. It seems to be a tad too long and butts against the back part of the trunnion, where the original splitter bracket was located (I took it off). I'm not quite sure how RK arm is supposed to be articulating but I don't see this as a big problem, most probably will need to grind less than 1/8" off that part, or RK arm. Certainly not something insurmountable.

Here's a stock image of the trunnion that looks similar to what I have:










I will keep you posted.

Regards,
Alex.


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## nohuhu (Jun 21, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


David,

Tried to install RK yesterday, looks like there are more differences between Unisaw and Grizzly G1023 than was apparent at the first glance:


Firstly, the holes that hold dust deflector on Unisaw (assuming I guessed them correctly) are present but not threaded:











Secondly, and most importantly, it seems that Grizzly's trunnion yoke is shorter than that of the Unisaw. This results in RK arm being limited in its upward motion, it can go about halfway and then it comes to rest against the back side of the trunnion, where the original splitter bracket is located:










Close up of the RK holder:


























I'm not quite sure just how much space the pivoting arm would need to clear the trunnion, maybe half an inch is all that is needed. There is some space between RK holder and typical 10" blade (I measured with two blades), a bit less than 3/16"; this could be salvaged to some extent but I think the most promising route is to shorten the RK holder. I very much like its adjustable and sturdy construction, it looks like it can be made a bit smaller without noticeable weakening.

I'll try to making and fitting some hardboard mockups before cutting any metal. This is probably going to take some time but I intend to overhaul this saw before placing it in service anyway. I consider this an ongoing engineering research project, so to speak.

While dry fitting RK I noticed that the anchor bolt holding RK stator fixed to the arbor arm is too long and won't clear the trunnion yoke:










Cutting it is no big deal but then I tried to take a pic of it and realized that I have overtightened the bolt considerably without even noticing it:










When I tried to remove the arbor arm it didn't want to go so I applied some brute force with a hammer via a piece of 2×4. This mild whacking was enough to cause the anchor bolt to unscrew somewhat, and the RK stator becoming a bit sloppy on the arbor arm. I realize that vibration of this magnitude is unlikely in production but I think this joint can be improved: instead of using a stamped anchor I will add a plate of the same 1/4" steel, a nut, and a counter-nut. Essentially the same anchor but beefier, and with enough thread on the nuts to smother them with red thread locker.

Another thing I noticed is that the RK stator opening is not quite aligned with the arbor flange, and so the arbor will need to be offset a little bit for the flange to clear RK stator. I don't think this is going to be a problem but I'm curious if it's the same way on Unisaw. Could be another subtle difference in construction. Do you have any pics of the arbor arm with RK stator installed on it?

Regards,
Alex.


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## drm11981 (Apr 9, 2017)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


do you have any kits left? I am very interested my email is [email protected]


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## makmadoosel (Aug 13, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I'm a new user on lumberjocks but I am restoring a 1950's unisaw (right tilt) and I'd love to get one of your kits if they're still available. I can't send a direct message because I haven't posted enough yet but I believe you can direct message me.

Thanks very much,

Michael McDonald
Vermont


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## possumtime (Nov 6, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I've been struggling to find a good solution for my 80's Unisaw as well, and this seems like a fantastic one!

If you're still fabricating and shipping these, I'd love to get one!

Any other users have comments on how it's been going? Reviews so far are great, but curious to hear more thoughts and experiences.


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## runswithscissors (Nov 8, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Possum: Yes, I do still have units available. It will take me a few days to assemble one. I'll let you know when I do.

Dave


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## possumtime (Nov 6, 2018)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Great to hear, Dave! Shoot me a PM, I actually signed up just to contact you so I don't have my 5 posts yet
- your fellow David


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## Gumby77 (Jan 29, 2019)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Hey Dave,

I also have just joined this forum to message you about the riving knife. If you could please email me that would be great!

[email protected]

Mike


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## joewilliams (Aug 1, 2012)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Dave,
could you contact me about the riving knife kits?

[email protected](dot)com

Joe Williams


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## Veeps (Sep 11, 2019)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


Dave, are you still making these. I recently picked up a 1983 unisaw.
I'm planning to build a riving knife kit but If you are selling plans, or selling kits, I would just buy one. Yours seems well engineered.
Let me know, thanks.


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## AntwanZebracakes (Apr 29, 2020)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I know its been awhile since you've probably checked this thread, but I have a 1940's delta unisaw that i'm looking to add a riving knife too. After seriously overthinking it I thought i should google and see if anyone had done an arbor mount of some sort. Low and behold i'm here. Just wondering if you'd be able to email me a copy of the piece of paper from the kit you selling awhile back. Thanks.


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## Gus_Gus (Feb 23, 2020)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I have a right titling detla unisaw from the mid to late 90's and looking to retro fit it with a riving knife. Curious if you are still making the kits for delta unisaws or if you have templates and plans to build it on my own. Much appreciated.


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## Downloader (Mar 1, 2021)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


**And….8 Years later from the original post here I am late to the party!

Hi guys, I just bought a 36-816 and I didn't come with the splitter. I need your help! lol.

@runswithscissors Hey brother, maybe I get lucky and you still have one around? Or any guidance you can provide me will be appreciate it.

Thanks in advance*
*


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## liqwoodstudios (Dec 12, 2021)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


So what ever happened to Dave? This was such a great idea.. just stumbled across this thread..


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## BigSplinter (Jan 13, 2022)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


I was inspired by this thread to make a similar riving knife four-bar mechanism for my unisaw and have been chipping away at it for more than a year (it's not high priority…).

Gratuitous additions: a bronze center hub and a cast iron main knife holder part. There's still some machining to do and to integrate the actual knife, but you get the picture.


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## bigblockyeti (Sep 9, 2013)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


^ If you can document what you've done to the point you or someone else can remake multiples, they would sell. Too many folks buying soulless tin from our country's enemies and calling it an "upgrade" from their tried and trued saw, makes me wonder how so many can be brainwashed?


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## Veeps (Sep 11, 2019)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...





> I was inspired by this thread to make a similar riving knife four-bar mechanism for my unisaw and have been chipping away at it for more than a year (it s not high priority…).
> 
> Gratuitous additions: a bronze center hub and a cast iron main knife holder part. There s still some machining to do and to integrate the actual knife, but you get the picture.
> 
> ...


I started building one but then got sidetracked with other projects. My interest is back into it. Can you share more in that bronze center hub. how did you attach it, etc.


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## BigSplinter (Jan 13, 2022)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


My bad - the center bronze piece is free machining brass. Not exactly bearing material, but it cuts like butter and I had a piece.
I machined a flat and OD on the stock cast iron arbor assembly to receive the hub. My rationale was that I wanted a larger surface area to constrain the riving knife holder. All lathe work. I lopped off the top to clear the underside of the table and leave some space to sneak in a wrench. By eye, bandsaw, and files. 
I totally admit this is a bit wacky and not necessary. I wasn't going for expediency, and if I were to do it again, there are a few things I'd certainly change. It was really seat-of-the-pants work.


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## grego19 (6 mo ago)

runswithscissors said:


> *Riving Knife retrofit for Unisaw*
> 
> Like a lot of people, I wanted a true riving knife for my older Unisaw. I checked out the Bolt On Riving Knife (BORK) and realized it doesn't maintain a uniform height relative to the blade, because it follows a bigger arc than the blade, being even farther out from the axis of the swing arm. Also, frankly, the means of attachment to the arbor doesn't look very robust to me.
> 
> ...


*Hello everyone,

I am new to LumberJocks, and have read the entire blog regarding the Unisaw riving knife. I too would like one of Dave's RK for my 1979 34-461 UNI (I purchased it new, and it is still a prized possession). I have survived without the benefit of a RK and decent guard for too long, and I want to upgrade my safety with the UNI.

It appears Dave may have decided to stop responding to this blog, but I am hoping for some positive feedback from anyone. Why it took me until 2022 to find this blog is a mystery to me, but I am hopeful. Thank you in advance.

Greg*


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