RE: [CAD_CAM_EDM_DRO] Re: Machine flex; How much is to much?

I measure about 0.001" deflection or less per hundred pounds
force on my shop machine spindles. I design metal capable cnc
stuff to be about the same. These are light industrial machines
similar to Bridgeport etc.

Typically this is non-linear with initial deflections being
a little less stiff and larger ones more stiff. That is normal
for ball and roller bearings.

A light duty drill press is often ten times softer.
I would think a mill drill would be somewhere in between.

Perhaps someone could measure one with a strong fish scale
and indicator. Most of the deflection is probably due to
the column.

Les


Les

Leslie M.Watts
L M Watts Furniture
Tiger Georgia USA
(706) 212-0242
http://www.lmwatts.com
Engineering page:
http://www.lmwatts.com/shop.html
CNC surplus for sale:
http://www.lmwatts.com/forsale.html
CNC carved signs:
http://www.lmwatts.com/signwp.html




-----Original Message-----
From: mayfieldtm [mailto:mayfiet@...]
Sent: Wednesday, September 24, 2003 10:47 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Machine flex; How much is to much?


Your Z-axis setup sounds like a nice way to go
on this type of mill.
Do you have any photos?
I have no clue about the deflection issue.
I would think that even the slightest flex would
cause vibration problems when milling.

Tom M.