Extruider motor stops moving

[bob 0]

So, after two and a bit weeks of (mostly) sucsessful printing, i've encountered another issue. for some reason the stepper motor for the extrusion stops moving near the end of the print. I noticed this on multiple recent prints such as the (shorter) screw print of http://www.thingiverse.com/thing:8796 and other objects about as hight (but with diffrent mass (as far as that pertains with 20% fill)).

I checked the gcode for any anomalys in the file, but there dont seem to be any.

I just noticed the gears are still turning, but about as slow as the hour hand on a clock (i.e. its only visible if you look at it for a while).

Anyone have any suggestions?

I plan on switing the extrusion motor driver with one for an axis to see if that may be the issue... but other then defect hardware I don't have any Idea what it could be. (is there any sort of garantie for the mortors?)

attached is the gcode... maybe someone will find something unusual in there... though I doubt it, since i did re code it three times.

Thanks

Note: I switched the stepper drivers and the extrusion still stops. so the issue is either with the motor or the gcode.... hopefully?

[bob 0]

Today I tried printing some Gcobe that I spliced a few weeks ago (right after I finished building the um) and the issue is the same, which proves atleast that the gcode is not the problem.

so if it is not the driver or the gcode that leaves the controller board or the motor it self

does anyone know if there is a way to test the motor with out switching it out?

how do I controll the second extruder slot via gcode?

[bob 0]

this time I printed the calibration pyramid, and watched the extruider motor the entire time. It seemed like it simply got weaker up to about the middle of the print where it just stopped alltogether (including retraction). I took pictures of the results...

[msurunner 2]

Today I tried printing some Gcobe that I spliced a few weeks ago (right after I finished building the um) and the issue is the same, which proves atleast that the gcode is not the problem.

so if it is not the driver or the gcode that leaves the controller board or the motor it self

does anyone know if there is a way to test the motor with out switching it out?

how do I controll the second extruder slot via gcode?

You might try swapping your Pololu drivers to troubleshoot and see if that's the issue... Make sure you have completely disconnected the power before swapping them!

[bob 0]

thanks for the suggestion, though I have allread tried that (see above). I wanted to switch the motors, but I notice that the extruder is not completely cicular, so that isnt an option :(