I recently built a prusa i3, running sprinter through a ramps/arduino set up and using a pronterface/slicer interface. All of the axes are callibrated correctly and move accurately, manually that is, through pronterface.

The problem begins when I start a print, x and y axis are fine however the z axis, although moves between each layer, does not move enough, which results in a print that is squished by about 50% in the z direction. I feel that the motors are not getting enough power to overcome the limitting friction between the threaded rod and bolt, ive got the trimpot on the stepper at max, heatsink is quite hot, got a fan on it and the z motors do get warm.

Ive been trying to print out this star thing but as you can see its not looking good.

Any advise on this would be great, thanks.
Adeel

Edited 2 time(s). Last edit at 03/11/2014 01:21PM by AdeelUK.

I had a similar problem a while back. I dont know if this is your answer but it turned out for me, I had to slow my motors down.
In slicer I went to the Start G-code page and added the line M203 Z3.5 and never had the problem again.
I beleive I started with Z4.0 and it was better so i just slowed it until things started sizing correctly.
good luck



M203 - Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in mm/sec

Note: this should be in units/minute, just like the F code.