Bench Grinder tool rest angle

[Bryan Lisowski]

I have done some searching and can't seem to find the answer I'm looking for. Maybe the answer is building the LN jig for use with a honing jig. I'm looking to reprofile the bevel angle on a few chisels. Right now most of my chisels are 25 degrees. I'm not talking about adding a micro bevel. If I wanted to redo the primary at 20 degrees or any other number, what is the best way to set the tool rest besides trial and error? If I place a 25 degree bevel against the wheel, would I want to raise or lower the tool rest to get to the 20 degree number?

On a completely separate note, for those that have CBN wheels, what is your preferred grit? I can only buy 1 at this time and not sure if 80 or 180 would be better.

[Bill Dufour]

I assume you are talking about a regular bench grinder which will not grind a flat planer surface. It grinds a curved surface so any tangent angle measurement is variable. For most grinders side grinding is a bad idea.
Bill D

[Frederick Skelly]

I made myself something like this, from Stuart Batty: LINK (https://www.woodworkersemporium.com/Batty_AG-1/)

Edit: Mine looks like this. The curve fits over the wheel and the flat on the tool rest. Works pretty well.
437547

[Bryan Lisowski]

Bill, thanks for the reply, however I don't quite get what your saying. First about side grinding, the grinding would be done on the face (1" width) of the wheel. Also after adding a micro bevel, multiple times it begins to creep up the face of the bevel and eventually needs to be reground to the primary bevel. Using an 8" grinder like I have, a tornek or other is the fastest way to achieve this, same would be true for grinding a new primary bevel angle. Now if your saying the bevel won't be flat because your grinding the bevel (which even at an angle, technically is flat) against a round object (the wheel) I get that may be true.

[Bryan Lisowski]

I made myself something like this, from Stuart Batty: LINK (https://www.woodworkersemporium.com/Batty_AG-1/)

Thanks for the link

[Derek Cohen]

I have done some searching and can't seem to find the answer I'm looking for. Maybe the answer is building the LN jig for use with a honing jig. I'm looking to reprofile the bevel angle on a few chisels. Right now most of my chisels are 25 degrees. I'm not talking about adding a micro bevel. If I wanted to redo the primary at 20 degrees or any other number, what is the best way to set the tool rest besides trial and error? If I place a 25 degree bevel against the wheel, would I want to raise or lower the tool rest to get to the 20 degree number?

On a completely separate note, for those that have CBN wheels, what is your preferred grit? I can only buy 1 at this time and not sure if 80 or 180 would be better.

Bryan, there are two methods I recommend. The first is the one I use currently, and for several years, the Tormek Anglemaster ..


https://m.youtube.com/watch?time_continue=1&ebc=ANyPxKoWjYyAeTorqCZ4ybI9 mV8qvEBuKyx01AwPPSKvGWgGLtrGbxrFI-8xWvI4oA5byrSQVxeLOrREkD6-tJLnXSnv_LsnOw&feature=emb_logo&v=zFmGfDULpiQ

The second is a simple jig you can make. Here is a link to the article: http://www.inthewoodshop.com/WoodworkTechniques/AngleSettingJigForDryGrinder.html

https://i.postimg.cc/3NXKHwzP/67-F0-B8-CE-754-D-4-B0-A-9-AAF-0-B7597-B0-A2-D7.png

As to CBN wheels, my preference is a 180 grit for plane blades and bench chisels. I have the dubious honour of being among the first, if not the first, to blog about these wheels for flat work: http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html

Regards from Perth

Derek

[Bryan Lisowski]

Derek, thank you. I will watch the video and read the articles.

[Bryan Lisowski]

Derek, good articles, thanks for the links. I'm leaning towards purchasing the angle master. Also great point on pointing out the flat versus radius wheels. Few questions. 1) You use the angle master with your CBN wheels? 2) In your article about the CBN wheels you mention you prefer hollow grinds, are you saying that you are using the grinder to put a hollow grind on the back of your chisels? I know Japanese chisels generally have a hollow grind on the back.

[Bill Dufour]

Bill, thanks for the reply, however I don't quite get what your saying. First about side grinding, the grinding would be done on the face (1" width) of the wheel. Also after adding a micro bevel, multiple times it begins to creep up the face of the bevel and eventually needs to be reground to the primary bevel. Using an 8" grinder like I have, a tornek or other is the fastest way to achieve this, same would be true for grinding a new primary bevel angle. Now if your saying the bevel won't be flat because your grinding the bevel (which even at an angle, technically is flat) against a round object (the wheel) I get that may be true.

All I am saying is you get a hollow grind of about 4" radius, not a flat plane, if the tool is at a constant 90 degrees to the spindle. It will have a straight cutting edge but the ground bevel will have a radius equal to the radius of the grinding wheel. So you are measuring a series of differing tangent angles not a continuous single angle with a set measurable number of degrees.
Bil lD

[Derek Cohen]

Derek, good articles, thanks for the links. I'm leaning towards purchasing the angle master. Also great point on pointing out the flat versus radius wheels. Few questions. 1) You use the angle master with your CBN wheels? 2) In your article about the CBN wheels you mention you prefer hollow grinds, are you saying that you are using the grinder to put a hollow grind on the back of your chisels? I know Japanese chisels generally have a hollow grind on the back.

Bryan, the hollow grind is on the face of the chisel, not the back. Japanese blades, both chisels and planes, are hollowed on their backs to facilitate easier lapping of the back since the steel there is the very hard cutting layer. One does not hollow their faces - it does not do any harm, but it is not does so traditionally ... probably because the contrast of polished hard steel and softer iron is so attractive.

Bevel face of a hollow ground Veritas chisel ...

http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp_html_71b2c2d0.jpg

Regards from Perth

Derek

[Brian Deakin]

I think the simplest and best solution may be to purchase may be to purchase 3 Stuart Batty angle gauges

https://www.woodworkersemporium.com/shop-by-brand/sb-tools/angle-gauges/

Please note they are accurate for an 8 inch wheel and within 1 degree on a 6 and 10 inch wheels

See page 8 of catalogue

http://www.dmwoodturners.com/wp-content/uploads/2016/11/Tools-Woodturning-CATALOG-AUG-2013.pdf

hope this helps

regards Brian

[Tom M King]

I use the Batty gauges. They would be better if the surface that fit against the wheel was larger, but work okay.

There is some guesswork involved anyway. As a cutter gets thicker, the angle gets sharper for a given rest angle.

[Rod Sheridan]

This won’t help however I went to a belt grinder decades ago, I can switch grits in a few seconds from 120 to a leather belt, the grind is flat and the wheel doesn’t need dressing.

I have the Viel tools model....Rod