Re: [CAD_CAM_EDM_DRO] stick slip blues

andrew abken wrote:

> I have a 1999 jet jtm-4vs mill that has rather sticky movement on the
> Y-axis. The problem is most pronounced when trying to move the axis at a
> constant slow feed, or when moving the axis less than five thou. Is there
> anything that can be done to reduce this tendancy, like adjusting the gibs,
> or using some lube other than vactra#2?

You might want to check for gunk in the ways, or around the gib. Is this a
tapered gib, or a straight one with a row of screws that press it in? How do
you lube it? Is it worse going one direction than the other? Is it worse
in one particular position (like the extreme ends) rather than another (like,
loose in the middle?)

You might also look for any looseness in the leadscrew bushings or the
nut-yoke assembly. If there is play there, it can make it much harder to
accurately position the table.

Good way oil can make it VERY slippery. After making the mistake of
using grease in my Bridgeport for years, I got way oil. While working with
leadscrews off at one point, I almost slid the table off onto the floor just
pushing gently with my hand! So, I doubt the lube itself is at fault.

Jon (more questions than answers, sorry)