Ball screws are practically anti-backlash, nevertheless,
FYO, you'd basically put the two nuts back-to-back, and
screw them together, until they almost 'bind'. now you have
a backlash-free nut. Of course, you wouldn't really mount
them back-to-back, you'd mount each 'back' to either side
of a mounting plate, and use spring washers to 'pre-load'
the screws, allowing some 'give' under severe pressures,
instead of making it a 'hard' mechanical back-to-back
interface. With a Grizzly, and 0.004"/ft screws, I'd not
bother with the antibacklash, as 'machine slop' coupled
with the 0.004"/ft will be the real test for your system.
'Less'n, of course, you're looking for some REAL accurate
work.
RayHex
----------
From: dspinnett <dspinnett@...>
Hi all, I'm kind of a CNC newbie.
I've converted my Grizzly G1006 to CNC (Master5/Mach1 and
Camtronics
4 axis servo), but the backlash and lead accuracy stink.
I understand I can get decent/cheap screws (.004/ft) from
McMaster-
Carr, and use a pair of taper or angular contact bearings
for the
drive end.
What I don't quite get is, how do you make a
'anti-backlash' nut
from two regular ball screw nuts? how do you connect them
to the
mills existing mount (two screws)... I've read about
using a spring
to pre-load, but I cant visualize how that works.
