Y-axis skipping steps

CrossFire ® PRO
1

Hi everyone, scratching my head re my y-axis skipping steps.
Typically on a medium sized part it’s just below 1mm.
Tricky thing is that it doesn’t always happen, like the scribed example in below photo which is crisscrossing all over the place and then ends up in the same exact place.

IMG_5442
IMG_54421920×2560 392 KB

Would appreciate any ideas!

Things I’ve checked so far:

  • Completely disassembled and assembled the y-axis.
  • Checked components for damage.
  • Stepper to computer connection tight and clean.
  • Coupling nut is tight and shows no sign of slipping.
  • Carriage preload is not super tight but has no play.

Only thing left I can think of is worn ball screw driving nut.
I did run it without oil for quite some time so guess that might be the reason.
Attached video seems to indicate a 0.1mm slop but then running 10mm back and forth it ends up in the same place anyway.
https://vimeo.com/770711639/ad1d20a93c

Any thoughts appreciated!

2

Perhaps a bad bearing or odd piece of spatter binding it up. Depending on if the carriage is up to speed when it hits the spot it will go over like nothing or bind before overcoming it. I’ve seen this with my own machine.

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3

I would think they could test it and see if it skips steps everywhere or just one area. that would help pin point a piece of spatter causing trouble

4

Yeah, would just need to go slow and zero in on the area. A video of what it’s doing when it misses a step would help a ton.

1 Like
5

Thanks for the replies!
I’m not sure if this occurs in a certain spot of travel, I would think not since really small parts all over the table can show the issue.
I recently replaced the leadscrew bearing but I guess the ones in the carriage could be at fault.
Might be worthwhile to take it loose and check them, I take it they are fairly easy to replace?

Langmuir is also sending a new lead screw nut so I’ll be switching that.