# setting up the tool rest on a bench grinder



## thedude50 (Aug 13, 2011)

I just got a new bench grinder A Porter Cable 8 inch with a lamp and variable speed it is a slow grinder and works very well. Of coarse I removed all the guards as i wanted to use my One Way Wolverine Jig on it. The grinders base was so high I didn't have to use the 1/2 inch riser block for the grinder like i did for my old 6 inch grinder. I mounted the tool locks centered under the wheels and was very happy with how straight they are. I then went to set up the tool rest for the regular tools. it is the flat square tool rest it is nice and wide and very stable. This is when it hit me How do I set this up for 25 degrees. I simply took a chisel I have that is new and has a known 25 degree bevel on it and aligned it to the wheel. that got me to thinking and I dont have an answer for this one on the top of my head but how do you set up a tool rest for bevels you dont have a reference for to get say an accurate 27 or 35 degree bevel on. Say I want to regrind some chisels to this new bevel for pounding out mortises or some other reason. I figured a set up block would work but what is the best way to get an accurate bevel to use as a reference for setting up the grinder. ALL HELP IS APPRECIATED. thanks Lance


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## Jim Jakosh (Nov 24, 2009)

Use a Wixie box to set the table angle!!


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## thedude50 (Aug 13, 2011)

I tried that it does not work because the wheel is an angle while I thought it would be fine it was off by miles


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## waho6o9 (May 6, 2011)

Basically the left indicator is the diameter of the wheel and the
right indicator is the angle you want.

Except you need the indicators reversed if I understand the
situation correctly.


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## thedude50 (Aug 13, 2011)

Yes as you are trying to adjust the grinder to the tool rest so you can not simply place the table at 25 degrees the bevel wont be the same because of the wheel Geometry. I discussed this with my wife she is a geometry teacher and said she can figure this out but that some poor woodworking math wiz most likely has already figured this out so I went back to the search engines thank god for Google There I found this link after many hours of searching different phrases. Here is the best answer I have found I will be making these jigs on Monday as I am Off to Pasadena in the morning for the wood show So Many tools so little time the trip should be great but I am on a tight budget as the state is screwing me again.

So if you like me and you want to get good results off your bench grinder so you can go from bench grinder to tormek to Whetstones or how ever you get a razor edge this is the key to setting up your grinder the right way. Click Here for the PDF to cure this Problem


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## Wildwood (Jul 22, 2012)

http://www.harborfreight.com/dial-gauge-angle-finder-34214.html

These angle finders with magnetic base will get you close. Can pay a little or lot guess they all about the same.
This will tell you angle of the table in relation to wheel most of the time. I leave the table at 90 degree if free hand sharpening a gouge or skew. I was disappointed with angle finder for set up to do scrappers. So just lay scrapper on table rest and adjust to wheel.


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## lwllms (Jun 1, 2009)

Because you're grinding on the tangent of the wheel, the tool rest needs to be set differently for the thickness of each tool. I make grinding templates the same thickness of each of the tools I grind. These are about 3/4" wide and 6" long. I cut a 25º bevel on one end and a 30º bevel on the other. The tool rest is set by eye so that the wheel contacts the bevel of the template, using the desired angle, in the center.

If you set the tool rest for a 3/16" thick tool and grind a 1/8" thick tool your bevel will be more obtuse than desired. If the rest is set for that same 3/16" tool and you grind a 1/4" tool the bevel will be more acute than desired. The grinding templates I make are the easiest way I've found to deal with grinding on the tangent of a wheel. Angle finders just don't work on grinders.


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## rance (Sep 30, 2009)

Lance, The pdf you provided seems to be a decent method, however, it may not work equally well for all users. It seems that some of the newer grinders have less and less of the actual wheel exposed thus not allowing a longer stick to be effectively used. The pdf does mention this though. In addition, the grinder table that comes with your Wolverine jig sits even higher, further limiting the use of this kind of jig.










They also do not address the issue of wheel wear affecting its use. That should be considered.

After thinking about this a little more, realize that the thickness of the blade being sharpened will have an effect on the Bevel Angle as defined in Figure 1 in the pdf. In other words, to get a 25 degree angle on a thin blade will require a different grinder-table angle than when sharpening a thick blade of the same angle.

SketchUp, SketchUp, SketchUp…

From my calculations(which could easily be wrong), using a new 8" wheel, the table setting for an 1/8" thick blade is 2.3 degrees different than for grinding a 1/4" thick blade. From this, I would say that the method in the pdf is in error. Actually this error would be inherent with many other gauges commonly sold. Do any of the gauges take the thickness of the blade being sharpened into consideration? Hmmmmmmm. But in all reality, unless you switch from grinder to grinder, 2.3 degrees may be a moot point. The biggest effect I could see is possibly grinding off more material than necessary, thus slightly shortening the life of the tool.

*Edit*: I see that while typing, lwllms has pointed out the same issue with the thickness.


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## thedude50 (Aug 13, 2011)

Ok guys I will send that information to the math guy that came ofp with the grinding templates so he can rebut this or confirm it . On the size of the wheel I think he did address it at the beginning or on the web page I got that linked to the Pdf I posted. I will check on this. My desire is to get an accurate grind on my planer blades that when I take them to the Tormek I am not regrinding a new bevel rather I want to be smoothing the bevel I already ground and I want it to be the same as the accurate bevel I got from the Tormek. Also I want to build an accurate set up block to hone my bevels with a honing guide. On most of my work I do this freehand but there are times when free hand is not the best way like when doing the Iron for my Shoulder planes trying to hold those little suckers straight is a bear I would give in and use the honing guide if I knew my set up was dead on accurate to my Tormek.

I want to thank you all for your help solving these issues once we do. I think A blog is in order to teach everyone the methods we figure out together so others don't have to struggle with Geometry and can get accurate repeatable results on their grinders.

Have any of you guys used the Tormek Grinder jig and if so does it address these issues? I am not married to the ONE Way jig and I can afford the Tormek Jig and if it does address these issues. I could be sold very easily.


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## rance (Sep 30, 2009)

Lance, I stand corrected. I went back and read more of the pdf(rather than just looking at the pictures). He in fact admits to the thickness affecting the accuracy. He also mentions referring to graphs which are included in Hollow Ground Geometry to determine the necessary angle corrections.

I think it is kind of odd that having seen many of these type of angle jigs, this is the first time I've ever heard of the need for corrections due to blade thickness. Interesting. I'm glad you posted this.


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## Dennisgrosen (Nov 14, 2009)

Dude 
I have looked into the tormek for a cupple of years 
and as I remmember it they only thought of the wheel diameter and the bevel angle
with that anglefinder Jiig 
nothing about thickness on the blades

thanks for bringing this up another new for me 

Dennis


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## JoeLyddon (Apr 22, 2007)

Lance, I'm not much into this… BUT… will this work?

Take, say a piece of 1×2 at a good length…

At one end, using a protractor, draw and cut the desired angle at an Endpoint.
This is the sharpening angle you want to grind on your wheel…

Lay the board on your adjustable grinding table & move your table around at the various angles until you can get your Wooden Angle against your grinding wheel flush & tighten it. 
This should be the angle required.

Place your tool onto your table (like the wood was) and grind your angle.

Does that make sense?
... or am I way off the mark?


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## OggieOglethorpe (Aug 15, 2012)

I cut 1/2" - 3'4" thick scrap sticks to the various angles I want to grind. Next, I make a mark on the end of the stick, distanced from the bottom edge equal to approximately half of the thickness of the tool I want to grind.

The mark is KEY, the angle is not enough.

These sticks are slid up to the wheel with the mark touching the wheel and I adjust the rest to match the stick.

Lee Valley sells a setup block that work exactly the same way, included with the Veritas rest but apparently not available alone. Scroll down to VERITAS ANGLE SETTING GAUGE

My sticks have one angle at each end. Five degree increments from 20-55 degrees, and a 27, took about 10 minutes to make. They work GREAT, account for wheel wear, and angles are easily repeatable.


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## Dusty56 (Apr 20, 2008)

Very interesting post , *dude*. Thank you : )


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## BillWhite (Jul 23, 2007)

This makes my head hurt.
I just adjust the rest to the blade, grind, hone, I'm done.
The obsession with accuracy to the nearest .000005" in woodworking has become absurd. Just know that I'm an old [email protected], and learned most of my skills (such as they are) from folks who did not have microscopic measuring devices unless they were working in a machine shop. I do use precision devices when metal working.
Know that I'm not beatin' up on those who wish to use the after market devices which promise extreme measuring. I just don't want to deal with changing batteries every 10 minutes.
Makes ya wonder how the old masters ever made anything using a ruler, a story stick, and a compass.
I'll put my planes and chisels up against any of those sharpened with a zillion bucks worth of "stuff".
There! I feel better now.
Bill
Bill


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## rance (Sep 30, 2009)

+1 to Bill.


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## Dcase (Jul 7, 2010)

+2 for Bill


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## thedude50 (Aug 13, 2011)

I agree bill my point is that I want to move from one accurate bevel to another this requires repeatable accurate angles if I am obsessive it is part of my OCD and I cant change who I am. However I will take you up on a comparison of my stuff and yours how do you propose we test the end results. shall it be who can cut the thinnest shaving with their smoother I know I have mine down to less than Rob Cosman's and I know mine are so good that they make wonderful photographs remember I am OCD and cant accept anything less than my best even if it takes me hundreds of hours to get this result.

Seriously though my issue is simple I want to be able to move from machine to machine and not get multiple facets on the Blade or Iron. I don't think this is Obsessive as you would not use a blade with two or more facets on it would you Bill? I really do suffer from OCD so I may be Obsessive.


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## thedude50 (Aug 13, 2011)

I have been trying to contact the author of the pdf I posted and I will post the whole article on the math as soon as I can.


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## Dennisgrosen (Nov 14, 2009)

Dude I have thought a little the last ten hours and my head starts to overload 
but all this with taking thichness in consideration is okay but at the same time 
wanting to go from the grinder to the tormek with out wanting to make a new bevel
without having to set up the angle on the tormek again 
maybee theoreticly possible …. but then you have to be dead on sure your 
grinding wheel and the wheel on the tormek has excacly the same diameter 
down to a fraction of a mm …. every time you want to sharpen a new blade

( I´m talking of going little to the exstreem side ) ... lol
for me its work by using lee valey´s sharpening jiig together with my waterstones 
but even there I maybee also go to the exstreem .... had put a 12000 grit stone 
on the wish list …. LOL

Dennis


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## oldnovice (Mar 7, 2009)

*Lance,*

If you have a line from the center of the wheel to the perimeter and create a line normal to that, then from that normal create the angle you want should give you the desired setting for your tool rest.

When I get a chance to get to my CAD program I will try to show this graphically if it is still needed!


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## hhhopks (Nov 22, 2011)

Thanks for the post.

My grinds are horrrible. My trial & errror method sucks.
A jig is definitely is in order.
I just want to get mine to come close, angle wise and reasonable straight.

I think the calculation is kind of tuff if you include thickness of the blade (different on each type of tools) and ever changing diameter of the wheel. All the setting of the jig will impact the grinding angle. Also we never grind with the top of blade right at the tangent point of the wheel.

For most of us, we need a simplified or method to approximate the setting (to get us with in certain % of the desired angle). Sometimes the analysis is way too complex but a skilled and knowledge craftsman has the knowhow of bypassing the complex math to get us to the don't care condition. Hopefully someone here in LJ knows the trick. My gutt feeling is that it involve some template or some setting guides.

If someone comes up with a math solution, it won't necessary translate into a practicle solution to emulate, but it is worth the attempt to get a better understanding. We need some math wiz kids who still knows all there geometry relationships.


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## GregD (Oct 24, 2009)

I see no advantage whatsoever to get too fussy about the primary bevel angle that is ground at the bench grinder. Setup blocks should be more than sufficiently accurate. The primary bevel just needs to be a bit shallower than the final bevel angle that is ground by honing, so that the honing process only needs to work a thin strip of metal next to the edge. Being able to maintain a consistent bevel while working through the honing process seems to be the key to getting a sharp edge and getting it efficiently.


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## thedude50 (Aug 13, 2011)

Thank you old novice. I would appreciate your input. I have contacted the author of the jig PDF and will post his input on this thread as soon as he gets back to me. He is with MIT so I know he is sharp. I am not a math wiz but my wife is, and she concurs with the author that the information on setting up the angle in the pdf is correct. If you look at the words carefully he gave you a basic fix for average chisel thickness and for average planer blade thickness.

I know if getting a good bevel maters to me it does to others and I want this thread to help educate people on how to get that. I don't do these things to be popular. I do them because I love to teach and to share Knowledge.
If I can get the brightest people to give up information for free I will do that. I hope you all find the information useful and that you and I learn from the question I know I am not the only one who asked this question.


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## ITnerd (Apr 14, 2011)

Hey Dude, Larry Williams initial post is correct, as is Barrys. The guy who wrote the initial article you posted covers it the Hollow Ground Geometry attachment, although he does so in MIT Speak. And the Veritas documentation Barry linked probably covers it best from the laymans perspective (it makes more sense if you look at the jig/guide they show):

You also need to know how thick the blade is to properly set the Grinder Tool Rest to your wheel. Place the blade on a reference edge running into the center circle, and note how many lines thick the blade is; most plane blades will be about one line thick, and most chisels will be less than two. *This height is important because the angle gauge must touch the stone at 1/2 of the thickness of the blade in order to correctly set the angle *(Figure 3).

None of this is a requirement to successful grinding, you can get the angle a little off here, and spend more time on your stones, if you jig it properly there. If you get the hollow sharpened at the wrong angle, you'll spend more time time honing the tip or heel of the primary bevel than you need to. If you dont jig it, noone will die, you may just end up with a less durable edge, or one that seems to tearout more than before. This is all about efficiency and repeatability.

As bill mentioned, if you have a primary bevel you like, you can use the blade itself to set the wheel, for it and other blades. It will just be most accurate if you adjust it to touch in the middle of the blade, and the other blades are the same thickness. I'm guessing a lot of old timers probably did this, take a plane iron with a bevel that worked for them, and use it as a template for one needing regrinding.

Larry Williams has ground and sharpened many more plane blades than most of us will ever see. I highly recommend his sharpening video, available at his website or Lie Neilsens. It covers grinding and sharpening, of straight and complex profiles, in great detail. I am definitely a better sharpener for having watched it many times. And to another of Bills points, he does it without any fancy gizmos; high speed grinder, belt sander, good stones and lots of expertise. Best money I have spent in pursuit of a sharp edge.

The main reason I enjoy it so much is that it doesn't come from the theoretical perspective, it comes from the perspective of someone who has sharpened a lot of blades, and wants to do it the most efficient and repeatable way. Although my old lady is going to kill me if I play it anymore - I put it on the big tv & stereo, and the background bluegrass music makes her nuts.


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## thedude50 (Aug 13, 2011)

First I want to thank you all the document I am trying to get Rance already found and linked in so that has already been done thanks Rance. Another thing I want to point out is I have no trouble making something sharp I own a tormek and a host of Naniwa stones that I know how to use accurately. I am trying to add a step to my process that will speed the rough grinding by doing it on the bench grinder instead of on the Tormek. However My needs aside I feel we should all be able to get the actual bevel we seek and not some other angle we don't want and that cant be moved from tool to tool.


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## oldnovice (Mar 7, 2009)

*Lance,*
I read the PDF and that's exactly what I said except that I didn't have any pictures!

The MDF that fits around the grinding wheel is providing the normal to the diameter of the grinding wheel and providing the 90° from which you determine the grinding angle. Offsets *parallel* to that angle are for compensation for the thickness of the tool to be sharpened.

Make sure that the MDF fits the wheel otherwise the normal will not be a normal!

*My question to you is why do you want to hollow grind chisels?*


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## thedude50 (Aug 13, 2011)

This was really not for my chisels but I sharpen for lots of people and I dont tell them how to do their stuff I simply do what they ask. I dont Hallow grind my chisels they never have even been on the Tormek which would be a shallow hallow grind. I was actually grinding plane irons. you see I run an add on Craigs list every few weeks about My Sharpening Business I have several clients now and if i did saws too I would be at this full time but I am not skilled yet in doing hand saw sharpening. and I really dont want to do this full time either. but i do want accuracy


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## rance (Sep 30, 2009)

Glad to help, Lance. I think with just a small set of templates, one could get pretty accurate results in sharpening a variety of blades & chisels while bouncing from grinder to grinder. I believe that the need to compensation for wheel size should be kept to a minimum. If you are still looking for other alternatives I've got some ideas if you are interested. I just don't want to muddy the water if you already like & trust the method(s) you are already using.

oldnovice, I'm not comfortable with the MDF gauge in the pdf. IMO, it is prone to needing 'fiddling' as the wheel wears or you move to another grinder. A good solution should not be that dependant on the exact size of the wheel.


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## oldnovice (Mar 7, 2009)

*I agree with the MDF part, I was just using what the PDF did.*

A solution that does not depend on the diameter of the wheel and/or thickness of the tool to be sharpened would be ideal.


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## oldnovice (Mar 7, 2009)

Using the instruction in the PDF and setting the desired angle at 25 degrees, the thickness of the tool to be sharpened has to be 0.042".

Any other thickness will result with an angle greater/less than 25 degrees!

*Please correct me if I made a mistake!*


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## thedude50 (Aug 13, 2011)

the chart on the second pdf that Rance put up is the one to read it has a lot on the calculation and how to do it for most of the common tools the rule of thumb on the first pdf will work as far as i CAN TELL AND SINCE I REMOVED THE GUARDS ON THE GRINDER AS I ALWAYS DO I dont have trouble with the measurement. However a point was made that the rest on the one way jig is too high. I need more input about this so i can contact one way and ask them to make another tool rest, but how much shorter does it need to be ?


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## oldnovice (Mar 7, 2009)

Lance,

Do you think that some kind of setup tool would be useful, not only for you, but for any others that my be in the same dilemma?

I have been toying around with an idea that *may just work* ... to early to tell, .... not enough PC time with my grandson on my PC doing his homework and playing games!

I am attempting to take the information in the PDF you posted and turn it into a setup tool!


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## thedude50 (Aug 13, 2011)

yes a set up tool would be good but once the wheel size changes the set up tool must change too it i read the data correctly.


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## oldnovice (Mar 7, 2009)

The plan I am working on will allow that!

Right now, if it works the way I want, you set the angle and the put the tool on the wheel to get the diameter set.
The maximum diameter is now 4" but after looking at some grinders, that may not be large enough.


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## thedude50 (Aug 13, 2011)

my wheels are 8 inches


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## JoeLyddon (Apr 22, 2007)

The latest issue of ShopNotes #126 has a great project for a Shop-built Belt Sander with a few tips on using it for sharpening.

Looks very interesting… you build the complete power sander!


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## thedude50 (Aug 13, 2011)

Joe I think i have more than enough tools for a sharpening shop let alone a wood shop I have been doing other peoples tools for a few years now and they all come back but frankly i pray for the day to come when i can turn away their work because i am too busy making commission furniture pieces. I am sure that if Don Peskeys bunch have come up with a home made sander it is worth a look just not by me


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## JoeLyddon (Apr 22, 2007)

Oh my…

OK…

Sorry I mentioned it…


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## thedude50 (Aug 13, 2011)

no joe it is worth a look by every one but me I have too many methods of grinding and putting a bevel on steel


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