[foxforever90]

Hi All,
Been lurking for a long time... Forgive me up, if I violate forum etiquette. It's been a really long time since I've posted in any forum.

Ok, I have an Avid CNC(cncrouterparts at the time) 24 x 48 cnc router. I have a Dell optiplex 7xx running linuxCNC and a g540 driving everything. The setup was very budget friendly at the time and it has worked very well for a long time (10+ yrs). However, I've started to notice issues. One came to light very recently while attempting to machine guns grips for a friend.

While running a 3D contour toolpath to create the overall surface profile (requiring lots of z motion) I noticed the z axis drift upward and it became very noticeable at the end of the program, i.e. ~0.040" higher than z zero (on a part only 0.15" thick).

So I tried to troubleshoot the best I could. Checked all the mechanicals on z. Reduced velocity and acceleration many times. Tried running the toolpath in open air. Separated control cables from router and vacuum (thought it might be a noise issue). Nothing changed. Same result every time. So then I decide to crack open the g540. Looked over all the drives. I noticed what appeared to be a couple cold solder joints but really didn't know what to make of it. So I just decided to swap z with y. Put it all back together ran the program. The surface was looking better than ever but then... yup now the y axis did the same thing. Drifts in negative direction.

My question... Is this a good indicator of a bad drive? Would it make sense just to purchase a spare g250x or should I send the whole thing (g540) back to gecko to go thru it? Reason I say that is I've noticed a lot of glitchy motion, motors seem to hiccup as I move the machine throughout its range of travel.