Layer Shifting

Good Afternoon!

I built a Mendel90 from a kit from Nophead, and it is using Melzi electronics. I am using Slic3r to generate gcode files and using Pronterface to operate my printer.

What I am noticing is that occasionally the printer offsets one axis slightly during a layer change. (Picture of this issue is attached) This has occurred on multiple design files, and operating Pronterface on multiple computers has resulted in the same problem. It seems fairly random, but the offset always occurs on a layer change.

Have anyone else seen this type of thing before? I suspect it to be on the data side of the electronics and not mechanical, but I can't be sure.

Thanks!
Matt

Not sure why you are posting in the RAMPS section when you have a Melzi.

If the shift is a multiple of 2.5mm it is skipping a belt tooth due to the belt not being tight enough. If it is a multiple of 0.8mm then the motor is skipping steps, in which case reduce the acceleration.

Is it one axis or both?

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[www.hydraraptor.blogspot.com]

Hi Nophead,

I was looking the printer over last night and noticed another problem, which may have been related. The Y-axis idler had worked its way loose and was moving side to side, which was causing a shift as the y-axis moved back and forth. We'll see if the layer shift issue crops up again, but I suspect that fixed it.

Thanks!

PS: Sorry about the post in the wrong category, I guess I missed the other options. Is there a specific subforum for Melzi, or does it fall under Sanguinololu?

There doesn't seem to be a Melzi sub forum, but there is a Mendel90 sub forum.

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[www.hydraraptor.blogspot.com]