Hey all, I have a 440 from 2016 and though I push a bit further than what is to be expected of a little 440, she serves me well. I had an indicator on the spindle/head and was moving Z axis up/down. I was seeing a pulse on that axis. I put the indicator on the ballscrew and found the exact same pulse (jump on indicator. I am trying to get to the bottom of this anomaly so giving this new forum a crack at it. I know the Z axis needs to be squared up, not sure what that entails exactly, but it’s more the pulse that is in question.
Thank you!
If you have a long reaching magnet tool, try running it along the ballscrew. I was seeing some “crunchiness” in some areas and it turned out to be some small ferrous chips / dust on my ballscrews left over from the factory.
When you say ( pulse jump) what do you mean? Do you mean the screw is turning and suddenly speeds up and slows back down to the initial speed? Or do you mean the screw is stationary and begins moving at a high speed momentarily and slows down for the remainder of the move?
If you watch the video, you’ll see the indicator increasing/dropping at a specific rate connected directly with rotation speed of ball screw. I find this run out is visible at the spindle. Gibs have been adjusted and I cannot figure out what’s causing it. Ball screw is turning at a consistent speed. It really seems to be run out, but why this is translating to spindle I cannot figure out.
Looks like your ball screw is bent. Is the deflection equal in both directions? If yes I would say screw is bent. If it’s only present when lifting the spindle it could be the extra load causing the screw to flex.