Extruder skipping
Ater many hours of printing i have started having problems with the extruder motor skipping. It cannot extrude at the rates it used to be able to. Last time i printed i had to limit volumetric flowrate to 5mm^3/s and it would still skip. I have tried the following:
1) Tried to swap the stepper driver to one from another motor.
2) Tried to use another socked with same and swapped driver
3) Replaced the extruder and stepper motor. (I had an LGX lite and am now using an orbiter 2.0)
4) Made sure that the config uses the 0.85A that the manual for the Orbiter specifies.
5) Replaced all cables from the board to the extruder
6) Reflashed firmware and reinstalled RatOS on a different Pi
I know its not clogged nozzle either, i can remove the nozzle entirely and still have it skip. I can hold back the filament with relative ease and it becomes easier the longer it tries to extrude.
I'm wondering if its the mainboard or the power supply....when i measure the power into the board from the PSU its all 24V. I'm at the end of my rope. Please help 😅
Solution:Jump to solution
I think I've figured it out. Took apart the hot end and tried to remove all the plastic in it. When i heated it up to remove the plastic i found that i could not get the blunt end of a 1.9mm drill into the tube that goes between the hot end and the heat brake. Something had hardened at gotten stuck in the tube. After using the sharp end of the drill and manually clearing out the worst of it, it can now extrude PLA at a rate of 25mm^3/s using a temp of 210C. So it seems that it was clogged in the...
17 Replies
How do the extruder teeth look?
Wait, you said you swapped the extruder with no effect
Yeah, brand new extruder. Same problem
Are you able to measure the voltage at the extruder?
I can try. I checked the vref on the driver and it read 1.15v atleast. Should i measure while running the extruder?
Given everything you've swapped I have to imagine it's the power leaving the main board that is the issue, whether it's the board or cables
If the extruder motor is the only one affected, have you tried swapping the motor port on the mainboard? Also to check the power supply you could try and measure the power supply output voltage under load (active heater, motors moving, etc.) to see if there is a significant drop.
Its getting 24V on both circruits
I tried to swap the socket that the driver and motor are plugged into, is that what you mean?
Yes, that is what I meant
Hmm, that is really weird, if only the extruder motor is not working, but it is not the socket, motor, driver or wiring. Do the other motors all still work without any problems?
As far as i can tell the rest moves at it should. No problems with bed movement or xy movement as far as i can tell. No layer shifts or other funny buisness.
In that case I would say it is most probably not the power supply as that should be affecting all motors equally. I am guessing you probably don´t have an oscilloscope to check if it is emitting any noise on the 24V rail?
When you swapped the sockets, was that a socket that was previously used by another motor, because in that case I also have a hard time believing that there is something wrong with the mainboard either. I know you said you redid the entire software, but is there any chance there is something wrong with the configuration for the extruder motor, maybe microstepping or the sense resistor or something?
I used a socket that was previously unused. I can try putting it in another motors socket. As to the configuration for the stepper, I've been using RatOS and it's built in configuration up until now. I only tried to modify that now during troubleshooting to try and make sure it was getting 0.85A. I can always try reinstalling. How strong should I expect the extruder to be able to pull? I'm afraid I don't have access to a oscilloscope though 🤔
I mean if you are using the RatOS defaults that should be fine, then again I have to admit I am more of a Duet/RRF guy, so I don´t know too much about Klipper and the Octopus Boards. I would certainly try using one of the sockets that previously worked for another motor just so that you can rule out that there is something wrong with the socket. I haven´t personally tried wrestling an extruder yet and unfortunately I don´t have a printer here at the moment, but according to this the extruder should pull with an equivalent force of about 6kg: https://www.orbiterprojects.com/a-benchmark-of-extruders/. So, if you attach a 6kg weight to a piece of filament, I guess it should be able to lift that.
I'll try the socket switch tomorrow and see what happens. Thank you for the help so far 😄
You checked the extruder and tried without nozzle, but what about the hotend?
Hmmmm...maybe 🤔 i did recently change it after a nasty crash...but it was a little after that it started having problems as well 🤔 is there much to check on the hotend?
In the case where it is skipping steps even without a nozzle the only thing to check for would be that there are no obstructions in the hotend. So if you can slide filament through the hotend without any issues it should be fine.
Solution
I think I've figured it out. Took apart the hot end and tried to remove all the plastic in it. When i heated it up to remove the plastic i found that i could not get the blunt end of a 1.9mm drill into the tube that goes between the hot end and the heat brake. Something had hardened at gotten stuck in the tube. After using the sharp end of the drill and manually clearing out the worst of it, it can now extrude PLA at a rate of 25mm^3/s using a temp of 210C. So it seems that it was clogged in the tube and not the nozzle 😅 thanks to all who gave me advice 🙂