Problem - y-axis missed steps? (solved)

I have a problem where my prints are destroyed, look:



[www.flickr.com]

Anybody seen this?

Printing from latest Cura sent some error messages in the console, so first I thought that was it. But it happens when printing from SD with pronterface as well...

Could it be missed y-axis steps? But that seems unreasonable since when I try to push it under power it is very firm..

One thing I have noticed is that the stepper circuits are quite warm. I know they have a temperature control circuit. Could it be over heating of A4898 and subsequent missed steps?

Edited 2 time(s). Last edit at 09/15/2013 03:33PM by Torkel.

The drivers shouldn't overheat unless you have a very high room temperature, I have run them in 30C ambient with no problems.

If the steps are multiples of 0.8mm then reduce the acceleration in Marlin from 4000 to 2000.

If they are multiples of 2.5mm check the belt is not slipping teeth.

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[www.hydraraptor.blogspot.com]

I had a similar problem with my Printrbot Jr. and it was because the belt wasn't tight enough, and would slip just a little bit every time it moved. Could that be a possibility?

Looks like it's solved

I lowered the acceleration, as per your recommendation Nophead, and it seams to have solved my issues - three prints now of same size as above image all successful!

Thank you for your tips!

Other things I checked was the belt tension (which was ok), and I removed the cooling fan and its hood-thing as that has gotten stuck a few times on protruding pieces of extruded plastic.

You might want to print one of these: [forums.reprap.org] to hold the fan duct more level and higher.

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[www.hydraraptor.blogspot.com]

You know, I _just_ saw that here on the forum and thought "I should print one of those"