New kit build, Nextruder gears not turning on first try
I can't get any filament through! As soon as I start to load, it seems as if nothing turns / the motor is just vibrating.
Things I've tried:
- redoing the gearbox calibration step
- tightening the idler screws (I could loosen as well - in any case, doesn't seem like this is the issue)
- trying to hand-feed the filament through (doesn't work)
- resetting the planetary gears
The real issue is that it seems as if the gears aren't turning / something is wrong with the connection between the gear and the motor. I've seen a bunch of stuff on this forum about fixing this with the Prusa Mini, where people just tighten the grub screws, but that doesn't apply because it's the MK4s! I took off the gearbox thing, this maybe illustrates what is going on (I know I'm not supposed to do this generally, just can't fix!) I'm not sure how to go about troubleshooting, would love tips or where to look!
RE: New kit build, Nextruder gears not turning on first try
the planetary gearbox should have a brass internally toothed gear around the planetary gears, they are a very close fit, so Prusa have designed an assembly tool to help you align the parts. it may be, that the gears are jamming because they are unconstrained.
If you take the gears off the motor shaft, does the motor shaft turn properly?
If it still buzzes, then there is possibly an issue with the extruder motor.
If the extruder motor rotates normally try fully assembling the gearbox but leaving the three cover retaining screws a little loose and try the motor again
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility.Location Halifax UK
RE: New kit build, Nextruder gears not turning on first try
That buzzing almost sounds like the extruder stepper motor doesn't have all 4 of its wires connected. Try unplugging and plugging the stepper from the love board. Pull all of the gears off of the motor to make sure the frame for the planets isn't binding on anything. Beyond that you might be best served by contacting Prusa support via chat so they can go through some of their troubleshooting scripts with you.
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs
RE: New kit build, Nextruder gears not turning on first try
Hmm, think I just made it worse. I have a hunch the problem here was that my motor had a cable disconnected or was in wrong - there was basically no slack in the motor cable, and i had to use pliers and such to try to stretch the cable into the slot. I just pulled the motor cable out, but looks like i might have twisted the pins it plugs into (and also, because it was so tight, not sure i can get it back in?)
My intuition is:
- I should first try to find some wire / "extension" to connect these - does such a thing exist? What is this part called, or is there a good way to do this? Just so I could align all of the pins on the loveboard easily and then do the stepper motor separately
- If this doesn't work, replace the stepper first
- If that doesn't work, replace the loveboard
Any thoughts? Is there any way to do this with just the current setup?
RE:
Looking at the kit build instructions, it looks like your extruder motor may be mounted upside down. The cable should exit from the top of the motor, not the bottom.
https://help.prusa3d.com/guide/5-nextruder-assembly_707767#713980
https://help.prusa3d.com/guide/5-nextruder-assembly_707767#715398
MK4S/MMU3
RE:
Looking at the kit build instructions, it looks like your extruder motor may be mounted upside down. The cable should exit from the top of the motor, not the bottom.
If this is so, carefully inspect your motor wires. There may be damage to them from being pinched between the motor body and the love board.
Also, your picture looks like you have ripped the motor connector off of the love board...
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs