Extruder not working
I have a RatRig vcore 300 that I originally assembled with a Duet mainboard. It was working OK, but for several reasons I've decided to remove the Duet and replace it with a BTT Octopus v1.1 + RPi. I've been working my way through the RatOS setup process and overall it has gone well: axes move correctly, BLTouch probes correctly, bed and hot end heat correctly, fans operate as expected). Frustratingly, one thing not working is the extruder motor. When I issue an extrude or retract command the stepper motor starts buzzing without rotation. I can move the motor manually so the gear system has no mechanical jams. I've double checked the wiring against the drawings and I see no errors. I've checked the wire harness to make sure there is continuity between the motor connector and MCU connector - all 4 wires have good continuity. There are no shorts between wires. Net, the cable appears to be good. Since the extruder was working with the Duet board, I'm thinking there may be a bad configuration setting causing the problem. My current printer.cfg is attached. Would someone please have a look at the settings and let me know if I've missed something? Thanks in advance.
4 Replies
variable_relative_extrusion: Falsedid you make sure to make your slicer setting match this?
metropolitan-bronze•13mo ago
I haven't yet created any gcode files in the slicer for this printer. The issue I have occurs when I send extrude or retract commands from the mainsail console.
I set the hot end to print temp (>150) for this testing.
Swap the two middle pins on one end of the motor cable
The problem is wrong polarity (the two coils in the motor are working against eachother), and that is an easy way to fix it 🙂
metropolitan-bronze•13mo ago
That was the problem. Thanks for the help. Greatly appreciated!