Re: [CAD_CAM_EDM_DRO] re: small variable speed motors

Your mail about poishing glass is interesting. I am quite
familar in working with glass. Many years ago I used to
hand bevel glass for artistic windows. Going through the
4 process's is a lot of fun.

Steve

----------
From: Elliot Burke <elliot@...>
To: CAD_CAM_EDM_DRO@...
Subject: [CAD_CAM_EDM_DRO] re: small variable speed motors
Date: Wednesday, March 29, 2000 7:50 AM

From: "Elliot Burke" <elliot@...>

Am polishing glass. This is done on a cast iron grinder rotating from
40-400 rpm typically for grinding, then a pitch lap in similar speed range.
Some people have CNC machines that can do this sort of thing, but for
prototype work it is mostly still done in a way familiar to amateur
telescope makers.

I think I'll use a VSR drill. After my first cheap one burns out, I'll
shop
for one with quieter gears. There is a screw inside the chuck which
probably is involved with removing the chuck, but the darn thing is too
tight to get off. With the chuck off the pulley could get closer to the
bearings, and put less moment into the output shaft. I suspect these drill
motors will have reduced life when used with pulley side loads.

Elliot Burke


Message: 4
Date: Tue, 28 Mar 2000 10:06:37 +0100
From: Andrew Werby <drewid@...>
Subject: Re: Digest Number 424

Does anyone know a cheap source for small variable speed motors?
In particular 1/10 to 1/4 hp, preferably geared to less than 1000 rpm.
These can be DC motors, I'll put a speed control on.

I thought of using a drill motor, but don't know how reliable these would
be.

Am making a polishing machine.

Elliot Burke

[What are you trying to polish with this? For most things, it seems a bit
slow, if you're driving the polishing wheel or (especially) point directly.
If you've tried using a drill for this and it works, then you're probably
okay, but it would be worth trying. Flex-shaft polishing machines, like the
Foredom, work at about 10,000 rpm, off a series-wound ac/dc universal type
motor. You can get these at Grainger's , although I haven't been impressed
by their quality.]

Andrew Werby
http://www.computersculpture.com

Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://unitedartworks.com


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