Bevel-faced disk sander plates?

Thanks, Dave.

I like that Micarta idea. On my disk is a piece of Formica, which doesn't give enough thickness for tapering, or would it?. How long did it take you to get the face tapered with a file? How much taper did you cut?

I've got a 1/2" thickness of particle board under the Formica.

Thanks again.

Steve,it took about an hour,but alot of that was checking for flatness.I didn't measure the exact angle but the edge ended up about 3/16" and I put a slight radius on the edge.Hope this helps,Dave.

Yes, the beveled face is a cone......but I hate to call it a cone because it is so subtle. When I turn the face, the outer edge of the disk typically ends up about .060-.080" lower than the center. (if the disk were laying flat on a table top)

There are no problems with the sandpaper laying flat on the disk.

Technically, the disk will generate a hollow grind. After thinking about it for a bit, I investigated. I generated a solid CAD model of the disk and sectioned it at various places to measure the amount of effective radius. (I know it is not really a radius...but follow me for a bit here).

If you consider a point on the face of the disk that is 1/2 way between the center of the disk and the edge for example, the disk would generate a hollow grind approximatly equivalent to that from a 42' (foot dia) contact wheel. If you were to lay a straight edge across this curve, you would see about .0006" max gap over a 1" span. That means if you grind a 1" wide blade, it would be .0006" from true flat. Is this something to worry about? I don't know....but consider this: what is the tolerance of the thickness of the sandpaper that you attached to the disk. If it is more than +/- .0003" then the flatness of the disk becomes irrelevant because the sandpaper will generate waves equal or greater in error.

In my opinion, the non-flatness generated by the disk geometry, is negligible when compared to human errors introduced from grinding by hand anyway.

Aside from the technical mumbo-jumbo.....the feedback that I've received from those that have used them has always been very positive. The benifit is that they can aid in cleaning up long flat grinds...either the edge bevel, spine, or tangs after your 2" belt grinder with a platen.

Wow, was this confusing?

These are just some of my thoughts and I understand that they may be debateable. Feel free to drop me a line if anyone needs some clarification.

Sincerely,
Rob Frink

Thanks, Rob. That helped a lot in my understanding what was going on there with the bevel.

I'll be back in touch, after a while, for one of those baby's, I'm sure!

Thanks, also, Dave, It's good to know that one can do it himself if so inclined.

I bought my disk from R.W. Wilson back in '95, check out www.customknives.com/grinderpics
IMHO, this is the only way to flat grind.

Stay Safe,
A.T.

Hey, you've go the same water bucket that I have. Cool!

Looks like the bevel goes in about half of the way on the face, is that right?

Thanks for the ocmments and the photos and resource.

"Looks like the bevel goes in about half of the way on the face, is that right?" Hello Steve, yeah the disk has a slight crown. There is absolutely no problem using any hard back grinding material. Normally, I only use wet & Dry paper,
but when I grind my camp knives and fighters I use a 40 grit hard back. I use the 3M #77 spray adhesive and spray it on the disk AND the grinding material. It does take a little extra work to seal it on the disk, cause you sure don't won't that to come flying off. I've never (knock on wood) had that experience. As I mentioned before, using the normal wet & dry sandpaper goes on easily and stays on.

Thanks, A.T. By the time I can afford a beveled disk, I might even know how to use it, thanks to all you guy's advice.

Steve,

I also have a disc from Ron Wilson. It has a 1 degree taper (according to him) from the center to the edge and works good. If I understand correctly, you are looking at the picture A.T. posted and it does look like the taper starts in the middle of the radius and goes from there, but I think that is just a shiny spot or something. The taper starts in the dead center of the disc and runs in a flat, or straight line from the center to the edge. The taper does not begin in the middle of the radius as it looks in the picture.

I just wish mine was mounted on a 1 1/2 hp variable speed motor !!

Guess you're right. I t must just be the highlight on the face.

Thaks for the clarification.