Different Z problem today

[ken_rychlik]

I got past the bit slipping and now have another Z issue. When jogging the Z up and down it is smooth. When running a file it goes down fine, but when it comes up for the next step over it chatters comming up. After every up chatter move it dives deeper on the next pass. Does anyone know what's causing this up chatter?

[tkovacs]

Seems like it is losing steps on the way up. What type of machine is this? My Z has springs to counter balance the weight. It seems pretty well balanced too - when I power off the Z will sag slowly down but sometimes will remain in place.

Could be a loose pinion gear too but I would think that would affect motion in both directions. Be sure the pinion is well engaged with the rack too.

Could be your z speed is too fast - mine is typically 1-2 ips.

[nat_wheatley]

Kenneth,

When I first got my machine, I had this same issue. It seemed to show up anytime I had used the keyboard/arrow keys for an extended amount of time. When I would reboot, it would go away.

I didn't find a fix, but now only use the keyboard/arrow keys to move the machine, when absolutely necessary. I haven't had the issue since.

[ken_rychlik]

I switched the z motor with one of the x motors and the problem went away. It's a prt. The springs and rack seemed fine, so I thougth it had to be the motor. The x has very little stress on it so I think it will be ok for a while.