odd print behaviour

Recently while printing the calibration prints and odd thing occurred. The extruder motor suddenly seems to extrude for the left side of the print job, but just jitters when printing the right side of the print job.

In an effort to cure the problem I have downloaded the latest sprinter firmware and uploaded that.
I have downloaded and installed the latest version of Kliment's printrun.

I have re-skeined an stl file and printed the gcode file with the same problems.

Makes for a very messy print.

What is odd about this is that previously all was working well. I've printed a full modular spool with few issues, and even a hinged wade's extruder. The resolution was a bit rough so I was working through modifying the Carve/Layer Height to get a better result. I printed the 0.5mm thin wall test print with beautiful resolution and was working through printing the 20mm box when things started to get ugly.

Any ideas?

Thanks,
Mike

Is the driver turned up enough? Do you have a resistor on the power supply to keep the load constant? Also, the belt on that axis might have come a little loose, giving a slight lag on the return.

Edited 1 time(s). Last edit at 11/30/2011 09:12AM by marnargulus.

I expect one of the motor wires is broken inside. At one end of the axis it makes a connection but at the other end it doesn't. See [hydraraptor.blogspot.com]

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[www.hydraraptor.blogspot.com]

Nophead,
You got it bang on. A broken motor wire, just inside the casing. Spliced new wire in and all was working again.

I placed a zip tie with a loop in the head around the motor and tied the wiring harness to the loop to act as a strain relief. Hopefully if it breaks again it will be beyond the strain relief.

Thanks all,
Mike