At the tire factory they machine rubber at room temperature by grinding.
The "cutters" are like the carbide grit edge type, looks a metal
grinding/sanding wheel. Try an abrasive type bit in a high speed spindle,
like a Dremel tool or similar. The finish of a white wall and white letter
tires is one of the results of this type of grinding. You do have to
control the feed, perhaps some air to get the rubber dust clear. Our white
sidewall buffers blow air while the grinders are down.

RogerN

"Wes" wrote in message
...
Today, I had to make some grippers for a machine that grasps a round part
and then drives
6 bolts in to 50 lb/ft.

I was using some rubber with fabric re-inforcement. I learned that drill
bits don't make
on size holes nor do end mills. Obviously, clamping forces have an effect
on hole
diameter.

I ended up moving up in size until the 8-32 shcs fit.

This was one of those close enough applications.

Any tips on machining rubber?

Wes
--

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