So I just picked up an older Prusa i3 on Craigslist. I also have a newer i3. To get it running, I uploaded the firmware that I use for my current i3 to the Craigslist printer. Everything seems to work on it except for one problem. My current printer has direct drive extrusion while the Craigslist one uses a gear system. This causes the extrusion rate to be way too slow and turn in the wrong direction . I've looked all through Repetier and slic3r but nothing seems to increase the extrusion rate. I have successfully reversed the direction in the configuration.h file but don't know how to speed it up. The gear ratio is approximately 5:1 so I need to multiply the speed of the extruder stepper motor by 5 or so. Any help on how I could do this, or on something else I should do, is greatly appreciated.

Its also in the config.h file.
#define DEFAULT_AXIS_STEPS_PER_UNIT
Thats the steps per axis on that line. My geared extruder is at 920 steps.

The diameter of the hobbed gear is also important.
Here is a guide for calibrating e-steps.
You can send M92 Exxxx from a terminal ( pronterface, repetier ) to test the new found value and then put it in the startcode of your slicer or reflash the controller. ( see answer above)

Edited 1 time(s). Last edit at 06/08/2017 02:18AM by o_lampe.