2 X 48 Belt Grinder (again)

Have you contacted a bearing maker with this question? That's what I would do because I have no idea which bearing is suitable for high speed work in an abrasive environment. The maker will know.
 
"Meets ABEC 1-9, AFBMA and ISO Standards." is a broad statement as far a a bearing is concerned.
What's the exact make and part number off the bearings you replaced and the newer ones you put in?
I know that SKF makes 'Angular Contact Ball Bearings' that will do 20,000+ rpm in the ~1.375" DIA range. There going to cost maybe $20-30/pc.
Should be able to find a pair on-line that would be inexpensive enough for such a nice looking machine.
Might have to adapt to a metric shaft size, but a 10K rated bearing shouldn't too tough to find.
 
Thanks for taking my question guys!
Middle- this is a home built design. The bearings are not "replacement." In fact, I just put SKF bearings in this! The SKF 1600 series is only rated at 5000 rpm but so far they are holding up. I need to change the design to incorporate a better series of bearing.
Good idea Mikey!
R
 
In followup to the prior comments, the SKF bearings are still holding up even running over the rated speed.

I finally replaced the platen with something more geometrically appropriate. I previously had a piece of angle iron in there which was not truly flat and not truly at 90 deg:

1578239329065.png

The platen itself is 3/16 x 2" O1 tool steel. It is in the annealed state so it it harder than mild steel but not as hard as it could be. I have a question for anyone with experience with tool steel. If I harden it how much warping can I expect to see? Would it be enough to interfere with the grinder operation? Obviously up to about a 0.010 errror would not be a big deal on a grinder platen. I have never hardened a large flat piece like this. Also, I guess hardening is not essential for this. Any thoughts?

Robert
 
I use precision-ground O-1 as a backing plate for my glass platen liner so no direct experience running it in contact with the belt. However, I spoke to a knifemaker about direct contact use and he said a lot of guys use tool steel directly under the belt and it seems to hold up well. He did that, too, except he used some other steel as it came from the supplier, no hardening.

O-1 doesn't move a lot when heated, especially if you don't machine it. For myself, I would epoxy a platen liner on it and call it a day.
 
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Thanks Mike- when they use tool steel directly it it hardened or annealed?
Robert
 
OK! Im not gonna mess with it then!
Robert
 
Just keep in mind that this comes from a knifemaker that does not require precision surfaces. For a tool grinder, a flat surface is important. I suggest a Pyroceram platen liner so wear never becomes an issue for you.
 
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