Home made Surface grinder

[JADknives]

Got a question for ya tool guys. I tried to make a surface grinder by making a slideing thing under the wheel of a bench grinder. It worked somewhat, my test piece was within .006 using a micrometer. My Question is can the wheel by made to apply pressure by a spring pushing it down on the material or would that just follow the surface up and down?

[Ray Rogers]

Doesn't sound like a good idea. A commercial surface grinder works by virtue of being able to hold the wheel RIGIDLY at an exact distance from the table with only the tiniest bit of pressure on the work piece. Using a spring loaded wheel would have pretty much the opposite effect. No matter if it followed the contour of the work piece or not, it would generate a huge amount of heat. When the work piece is allowed to get hot on a commercial surface grinder you get warpage in the work piece....

[JADknives]

That makes sence. I'd like to convert it to a belt so I can change grits. Would it be better to have a rubber coated wheel or a hard wheel?

[george tichbour]

A very hard rubber wheel would be preferable about 100 durometer Shore A hardness would be my guess. I have a through feed grinder with 80 durometer Shore A wheels and it tends to round edges a bit.

[Ray Rogers]

I have a belt conversion on my surface grinder. It uses one of Bertie Rietveld's wheels which, I believe, is a 90 durometer (anyway, it's way harder than a regular contact wheel). See Bertie's info on these wheels at http://www.batavia.co.za/Surface%20Grinder.htm

[JADknives]

Thanks for the info guys.

[Otto]

hmmm........ post it!

[JADknives]

Here we go it's a dandy. Made the wheel out of wood. I wanted to see if it would work before I buy a real wheel. Can grind 12 inch long and 3 inch wide.

[Ray Rogers]

Cool! Does it hold within .001 over that 12" length ?

[Dwane Oliver]

That is cool. How long is that belt ?

[JADknives]

Well I just ground a 10 inch blank and it measured at .003 from one end to the other.

Has a 1 x 30 belt.

[Dwane Oliver]

WOW , thats pretty good for what you have there , you've got me thinking now. Great job.

[chip williams]

I like it! how do you hold the blank down?

chip

[tmiller5087]

Great idea James, looks good. 003 is pretty impressive. I have a question about surface grinders for you all, well an idea. I was looking around the web for surface grinders and came across dual wheel grinders that have been used in the auto industry for years. Look very exspensive. So my question is why couldn't one put two disc grinders face to face with one adjustable for thickness and pressure and use that as a surface grinder. Add one of them little coolant pumps like is used on end mills and horizontal bandsaws to eliminate heat. Would need a fixture thinner then the steel to hold the steel and slide it thruogh the discs. plausable or dumb ass idea? whadda think?

thanks Terry

[Ray Rogers]

Terry,

Those discs will have to be perfectly flat, perfectly parallel, and perfectly rigid and one of them will have to rotate in the opposite direction than the other. Could be a handful trying to change the sand paper and get everything aligned again,

Aside from those issues, it might work but I'm not sure it would be worth the trouble. If I were going to build a surface grinder, I think I'd do something along the lines that JAD followed....