Extruder motor only working when dry

Hi all,

I got my first 3D printer a few days ago and I just finished building it (it is a Prusa i3 kit). Everything seems to be ok, I customized the Marlin fimware to my needs and I should be ready to go. However I found an issue with the extruder (Greg's Wade). When I was about to calibrate the extruder motor I noticed that the motor did not have enough torque to feed the filament (ABS, 3mm) into the extruder. When trying to troubleshoot it, I modified the firmware so I could operate the motor with a cold Hot End. Then I noticed that when the hot end is cold the motor works just fine but, when the hot end is hot, it seems to lose all its strength. I believe the motor is a standard NEMA17 Stepper motor. The board is an Arduino Mega 2560.

Any help on this would be much welcome! thanks in advance.

Just adjust the potentiometer in the stepper driver with and anti-static (plastic) screw driver.

Quote
ggherbaz
Just adjust the potentiometer in the stepper driver with and anti-static (plastic) screw driver.

Thanks.

CW or CCW and by how much?

You can do it three ways:
CCW all the way until motors don't move any more and then adjust from there until motors moves without hesitation.
CW until motors whine then reduce until motors move smooth.
Then there is the mathematical way measuring the stepper driver with a volts meter. But option 1or 2 are sufficient. ( you can read the wiki page and follow the instructions) .

Edited 2 time(s). Last edit at 11/02/2014 10:40PM by ggherbaz.