RE: [CAD_CAM_EDM_DRO] Bent Nook ballscrews ?????

Hi Kim -

Are you designing your motors' pushing force to be equal to the
max cutting loads you expect? If so, your motors may be
relatively small, with little reserve acceleration force, OR, you
are expecting HUGE cutting forces, and you expect very small
acceleration forces. I would think the max "pushing" force of a
motor on a machine tool would be far greater than the expected
cutting forces, partly in order to leave some force available for
accelerating the machine around while following the toolpath.

Does anyone know of a modern high-performance machine tool that
uses spring elements in their preloaded ballnuts?

Regards,

Carlos Guillermo
VERVE Engineering & Design

-----Original Message-----
From: Kim Lux [mailto:lux@...]
Sent: Monday, August 11, 2003 12:17 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: RE: [CAD_CAM_EDM_DRO] Bent Nook ballscrews ?????


A substantial amount of force would have to be greater than the
pushing
capacity of the motor so that there was never a force that would
displace the nuts against each other. If the spring is weaker
than the
pushing force of the motor, then it will displace the backlash
under a
heavy cut.

As soon as the nuts are adjusted for the maximum force the motor
is
capable of moving, there isn't any force left to move the cutter.

Kim