RE: [CAD_CAM_EDM_DRO] Rotating nut ballscrew

Agreed rotating screw would not work here. Spinning the nut
could be ok but there are some issues if they are not specifically
designed for it....like dynamic balance and grease slinging. The
drive for rotating nuts is a bit complex and expensive as well.
It does have great advantage though.

If you went with the belt and could handle perhaps .1 mm repeatablity
and somewhat less stiffness that would be the best bet. Speeds of
10 m/min or more would be easy.

The other Les


Leslie M.Watts
L M Watts Furniture
Tiger Georgia
(706) 212-0242

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http://www.lmwatts.com
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-----Original Message-----
From: Les Newell [mailto:lesnewell@...]
Sent: Friday, December 10, 2004 4:15 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Rotating nut ballscrew



Hi,

I am planning a router (about 600mm x 1200mm) and I have some suitable
ballscrews. The problem is that they are only 4mm pitch. As I am looking
for a feed rate of at least 4m/min, preferably 8m/min the screws will
have to rotate at anything up to 2000RPM. Obviously spinning a 12mm
diameter 600mm long screw at 2000rpm is going to result in the screw
whipping and generally trying to destroy itself. It would not be too
difficult to spin the nuts instead but would they function correctly at
2000RPM? I have seen plenty of rotating nut systems but none that have
been spinning at high speed.

The other alternative is to forget the screws and go for HTD belt drive.

Les