Y axis slipping.

Hey folks, I'm wondering if someone has met this problem before.

I'm running a mendel, (Marlin 0.9.10 B, slicer for Gcode, pronterface)

Things are printing fine until the print head gets around 1/1.5cm off the print bed then the print starts slipping along the Y axis. Suddenly the machine will print the next layer offset by 1-5 mm.

I can't figure out for the life of me what's happening, I've checked the file but there's no problem there. The problem seems to occur in the last few layers but it's different every print.

Any thoughts?

Edited 1 time(s). Last edit at 02/27/2013 09:27AM by cyberminion.

Hey all, I've uploaded a couple of pictures to give a clearer view of what's happening.

Hoping someone can help me here, it didn't used to do this!

I had a similar problem on my X axis, and it turned out that the grub screw on the pulley was loose.

Loose/slipping pulley.? Belts not tensioned correct.?

Thanks for the suggestions guys.

The grub screw on the motor seems fine, I'll check the belt in a little while.

I actually managed to make a decent print a couple of nights ago. I think the trick might be just to not sit watching the darn thing!

Thanks for all the help!

I have had a few issues with the hot end hitting the existing print when moving to the start of a new layer. This causes the same type of problem.

I think this is caused primarily by the fact that the start of a new layer moves all X, Y & Z at the same time to the new starting location and in some cases the existing layer has risen slightly and the hot end is still in the process of moving up as the head moves across the print at a fast rate.

I am litterally just about to post a question to see if there is a way to make the Z move before moving the X & Y for the new layer.

I have tried this by editing the G-code and it helps, but it is a pain to edit the G-code manually.

For your issue it may also be the current setting for the motor drivers that needs increasing a little to stop the motor slipping. I needed to do this for my extruder since it kept slipping a lot. Be careful increasing the motor drive current though since you can burn up the motor if you increase the current too much.

BR,
Steve

Have you checked if the stepper driver has been adjusted correctly? If turned up too high the stepper driver will shut down to protect itself. If turned down too low you will get a similar situation because there is not enough power to drive the motor.

I had that problem on the x-axis.
My issue was that the belt was not aligned straight.

Check that the y-belt is completely straight for the whole range of movement of the bed.
move the motor and /or the bearing on the opposiute side so that the belt runs straight.