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Forum topic by sgtq posted 08-24-2011 05:58 AM 913 views 0 times favorited 5 replies Add to Favorites Watch
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sgtq

370 posts in 2138 days


08-24-2011 05:58 AM

Topic tags/keywords: tablesaw question tip

So thanks a great deal to Knottscott I managed to learn alot about table saw blades today. I keep realizing how very little I know about this fairly new hobby of mine but I want to be a true craftsman someday, sooo I’ve decided to ask a question every week or so that with all of your help will ensure I become a better woodworker.
My first question
I know what a riving knife looks like but have never used one on a tablesaw, I would highly appreciate if somebody explained its importance and its actual use. I just bought a new tablesaw and if it doesnt have the riving knife I will be looking to get one to install but I should really know its purpose in order to properly utilize it

Question: What is Riving knife and what purpose does it have. How does it make woodworking better,safer or more accurate?

Thanks in advance.

-- There is nothing wrong with America that cannot be cured by what is right with America. ~William J. Clinton


5 replies so far

View Taigert's profile

Taigert

593 posts in 3302 days


#1 posted 08-24-2011 06:31 AM

The easy way to explain a riving knive is that it keep the material you are cutting in line with the blade. If you were to let the piece you are cutting catch the back side of your blade, that blade will grab the material and throw it right back at you. And it will have a lot of force with it. I have seen a piece come out of the saw fly 20’ feet into a metal door and leave a sever dent in that door. Had it hit someone they would have been impaled and perhaps dead.
Trust me it is not something you ever want to have happen. Guys have had their hands pulled into the blade and all kinds of nasty things. That is also the reason you never want to stand in line with piece you are cutting. Remember most kick backs hapen on RIP cuts, just due to the amount of material passing the blade.
My strogest advise is to contact your local night school or trade school in your area on take a course on shop safety. money well spent. Check with where you bought your saw, Woodcraft or Rockler
Go to YouTube on enter Tablesaw kickback in the search, there are some violent demos in there.
Good luck

-- Taigert - Milan, IN

View Greg In Maryland's profile

Greg In Maryland

550 posts in 2460 days


#2 posted 08-24-2011 07:03 AM

A riving knife and the blade guard/splitter that came with your Ridgid TS3650 are basically the same—they prevent the cut wood from closing after the cut and pinching the saw blade. As Taigert explained, wood pinching a blade going 3450 rpm does not result in anything good.

However, the approach to avoiding kickback taken by the riving knife and the splitter is completely different. In general, a splitter sits atop the table and does not change elevation as the blade is cranked up or down. It does, however, change as the blade is tilted from 90 degrees, i.e., it tilts also.

What makes the riving knife different is that it is attached to the trunions (or somewhere under the table) immediately after the blade. This permits the riving knife to change elevation as the blade is cranked up and down. Of course, it also tilts as the blade is tilted from 90 degrees.

The beauty of a riving knife is that it does not need to be removed when doing non-through cuts. i.e., dados, tenons, etc. With the equipment that is standard with your TS3650, you would have to remove the splitter/blade guard in order to do these cuts.

Here is link from Fine Woodworking that provides further information: Link

Based on another thread of yours, I don’t think that you can purchase an aftermarket riving knife for your TD3650. You can purchase and/or make splitters that attach to your throat plate. Here is shop made one and one from Rockler. I have not used either, so I cannot speak towards their effectiveness or practicality.

I also have the TS3650 and found it to be a very good saw for where I am in my woodworking. I built an outfeed table that I pilfered from the Ridgid Forum. The builder, BobD was quite nice and answered several of my simplistic questions.

You also are going to want to do something about the dust control. I enclosed the cabinet as much as I could and attached my DC to a home made port. My next task is to modify the blade guard so that it is also connected to the DC.

Lastly, the TS3650 tends to rack from front to back. Evidently Ridgid didn’t engineer the bracing on the sides well enough. I understand the solution is to add shop made braces on the sides. I haven’t done that yet, but intend to.

The Ridgid Forum is a good source of all things TS3650, so I would check it out if you have questions specific to your saw.

Good luck!

Greg

View CharlieM1958's profile

CharlieM1958

16241 posts in 3680 days


#3 posted 08-24-2011 05:28 PM

cr1: I’m not criticizing your stance, but I’m just curious…. What kinds of cuts does a riving knife interfere with? I don’t have one, so I claim ignorance on this issue.

-- Charlie M. "Woodworking - patience = firewood"

View Bertha's profile

Bertha

13003 posts in 2155 days


#4 posted 08-24-2011 05:47 PM

^I’m guessing he means “fixture” interference. I have the same gripe with my splitter. I think I’m headed for a serious kickback injury because I’ve never had one. I’m terrified of my table saw (and jointer especially). I’m still probably more careless than most of you, given the recommendations I read.

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View Taigert's profile

Taigert

593 posts in 3302 days


#5 posted 08-24-2011 06:01 PM

I have the new style Delta and I can have the riving knife in the upper position for through cuts. And what I love is the lock at the front just under the table, I just give a gentle pull on the handle and I can drop the knife to the height of the top of the blade to make non through cuts or just pull up on the knife to raise it to the upper position or remove it all together.
I’m not sure how the other saws are doing this but, I have two different size knives one for thin kerf blades and one for regular full kerf blades.
I personally find that the only time my riving knife is off the saw is when I’m running the dado blade.
I know that my worst bad habit is not using the guard. And I will be the first say it, I get Friggen Lazy sometimes. Delta has a great Guard system it’s easy to work with work never hangs up on it, easy to see through, easy on and off.There is no excuse it’s been plain Lazy. The part that I tend to forget is the bad example it shows my son who is now 17 and has all the answers to the worlds problems. He is still under my watchfull eye when he is in the shop, the only major tool he is allowed to run without me there is the lathe. He tends to jump on my back when I’m preaching SAFETY first. Oh my other bad habit on the TS is push sticks. I make him use one if his skin is within a fist (my fist it’s still the larger one) of the blade. Every once in a while he’ll catch me trying to shave a layer of skin off a finger without a push stick.
Why is Gods name am I confessing all my mortal sins? I had best quit before I incriminate myself,

-- Taigert - Milan, IN

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