Modifying extruder rotation

[cmcrook 0]

I have an Ultimaker 2 which admittedly I have not been happy with. Since I received it I have had a constant issue with the gear on the extruder stepper motor grinding the filament. I tried every possible solution I could find from ensuring the nozzle is clear, super slow printing, various filament tensions, and many others approaches. None have been successful. It has gathered dust on the shelf until recently since I require some special prototyping parts. I decided to use an extruder assembly from another printer of mine I have since disassembled. However, I require the extruder to rotate the other direction in order to use it. Are there any ways either in Cura or manually to modify the direction of rotation for the stepper motor, preferably in software, because I would like to avoid making possibly damaging modifications to the PCBs?

[ultiarjan 1,223]

If you have the 2, just take the firmware of the 2+ (the 2+ has a geared feeder, so the stepper rotates the other way around)

If you take the tinker firmware you can also easy change the e-steps to adjust for any gear ratio, just in the menu on the printer.

https://github.com/TinkerGnome/Ultimaker2Marlin/releases

[gr5 2,271]

What arjan said. It's easy to adjust steps/mm for the E axis but you can't reverse direction without loading a different firmware so you have the 2 and the 2+ to choose from. The 2+ firmware works fine on the 2 except for that reverse rotation.

Another choice is to swap 2 of the wires on the stepper. Take one of the twisted pairs and swap those 2 wires (either pair is fine) and the stepper will reverse direction.

The problem is probably not with the feeder - it's probably with friction in the head. Best guess would be the teflon part - it's probably time to buy a new one. Do you have an Olsson block? If not getting one makes it so much easier to diagnose friction in the path from the feeder to the head (sometimes it's in the bowden but most often in the teflon part). And sometimes there is a partial nozzle clog. In call cases having the olsson block and the ability to remove the nozzle and let it cool and insert filament backwards from the olsson block lets you feel the friction.