Setting Grinding Angles in the Digital Age

[RickKrung]

...snip...
The reason I'm curious about using the digital angle cube with my Tormek, is that many woodworkers use them in traditional manual sharpening to help set up a wide variety of angles in a sharpening jig. They place the digital angle cube on a flat stone, zero it out, and then place it on the face of their plane blades and chisels, and raise the blade up or down to the desired angle, which will register clearly on the screen of the digital angle guide. I can't think of anything simpler or more accurate in terms of setup. No distances to measure, no crouching down to see a sliver of light underneath the edge of a blade. Modern woodworkers are finding more and more uses for these little marvels. In a recent issue of Fine Woodworking, someone even suggested using them in place of winding sticks!

I don't yet own a digital angle cube that can measure 360 degrees (4 X 90), so I thought I would ask members of the forum if they have tried it for setting angles against the side of the Tormek wheel. Rick seems to have had great success with this procedure for his turning tools. Rick, have you tried it with plane blades and chisels?

The digital angle cubes can be used exactly as you describe and want.  I am pleased so far with what I've seen regarding the accuracy of the ones I have and will at some point explore a couple more methods for demonstrating their accuracy. 

I have had success using the angle cube in metal machining and woodworking.  I have not used one for grinding/sharpening anything yet.  I do not do wood turning, so have not and will not be sharpening any turning tools.  I am quite confident that the tool can be used as you have described. 

Rick

[sweet_strings]

Wonderful. Thank you, Rick! I look forward to hearing about your experiments with these Digital Angle Cubes in relation to setting up angles on the Tormek.

Sweet_strings

[RickKrung]

First in a few posts showing the Angle Cube in action, on instruments I have in my shop, for setting up parts to be machined. 

1) Machinist Square
My set of machinist squares are not top quality.  I compared the square pictured to one of my angle blocks and noticed a little bit more light on one side than the other, indicating it isn't perfectly square.  The Angle Cube may reflect this. 

Zeroing the AC on my mill vise.  The AC is being used upside down, to demonstrate that it doesn't care which side is used. 


Reading the angle.  Apparently off by 0.15º, which may be a reflection of what I observed with the light.  It also is within the specs, accuracy of 0.2º. 


2) Precision Angle Blocks
Two angle blocks, used for holding material at 90º.
Zeroing on the mill vise.


Block One


Block Two


3) Adjustable Angle Block
Settable to any angle, using a vernier scale marked in degrees and minutes.  This image shows it set to zero.  Note that the lines at zero are lined up and how all the lines on either side of are off corresponding lines a little bit.  This is the same principle as the "old fashioned" slide rule I used in college and the vernier calipers I used in my father's shop before the advent of dial or digital calipers. 


Set to 0º.


Set to 15º.  Off by 0.15º.  This seems pretty good on the surface, given that the vernier is only marked in 10 minute intervals.  However, 10 minutes = 0.16666º, so I have to wonder why the AC is showing it at what is essentially 10 minutes.  Whatever the reason, it is still within specs for the AC.


That is all I have for tonight.  I have two more methods of setting angles.  With one of these, I plan on showing a number of measurements of the same setup, to help understand how repeatable the AC is. 

Rick

[Ken S]

Interesting post, Rick. There is much fertile ground to explore.

Borrowing a technology used in many trades, I believe the efficient use of these new discoveries will lie in the combination of careful initial set up followed by gage blocks ("gauge blocks" for those you who still speak English, TT    ) Gage blocks, like the kenjig, can reproduce set ups with high accuracy while not requiring repetitive measuring.

Ken