Extrusion trouble
Hello Prusa forum members. I am having extrusion problems and have tried everything that I have read and am having no luck. I would appreciate any help that you can provide. What I am observing is snapping and skipping of the extruder. My prints mostly start off very good, but at some random point (@ 11mm z-height yesterday) I start getting a snapping and clicking and I can watch the nozzle jumping up. The print will then go to hell and never recover. It is often at a constant frequency of 2sec. Things I have tried:
1. Cold pulls using PLA, ABS, PETG, cleaning filament. Tried various temperatures. Filament always comes out clean
2. Pushed though cleaning filament @ various temperatures
3. Increased nozzle temperature
4. slowed down print speed
5. titrated the live z adjustment
6. Pushed thin cleaning wire up into the nozzle while nozzle is hot in attempts to dislodge anything stuck
7. Have ordered a new nozzle from Prusa
I would appreciate any feedback. I am unable to print anything at this point and it is very frustrating. Thank you.
Re: Extrusion trouble
A couple of quick qualifier questions:
Those really change the variables.
Can you summarize your print & slicer settings?
It sounds like you're getting some filament flow, so a partial clog is a possibility. If you heat up to printing temp, raise Z to max and extrude material, does it flow straight out of the nozzle, or angle to one side as it comes out? There may be a bit of build-up initially, but once it starts flowing, it should come straight out of the nozzle.
Re: Extrusion trouble
bobstro, thank you for your reply. To answer your questions,
1. I am not printing in an enclosure
2. I AM printing through Octoprint
3. I keep my house warmer than most, ~ 80degF
I'm not sure which slicer or printer settings you would like me to share, but for speeds I use 45mm/s on the perimeters and 100mm/s on the infills. I am using Slicr Prusa Edition, FWIW. I am experiencing this issue regardless of material and I have used PLA, ABS, and PETG all from several manufacturers.
Regarding the angle of filament exiting the nozzle, I often see both situations, where is comes out straight down and comes out at an angle. I do try to clean more thoroughly when I see the angular exit.
Do you think this could be a result of Octoprint or the ambient environment? Or both?
Thanks again for your assistance. I really would love to get back to printing. I am uneasy when I start a print right now because I am always worried and listening for the snapping from the other room, having to check on it constantly. It's like I had another kid (that my wife doesn't like). 😆
Re: Extrusion trouble
I'm understanding that this is a persistent issue. As a troubleshooting step, I would suggest running the exact same gcode as a print from SD card, bypassing Octoprint. If the print succeeds without issue, that will provide a valuable indication of where to start. There have been reports traced back to Octoprint timing issues. If there are still problems, then you can shift focus to hardware and slicer settings.
[...] What I am observing is snapping and skipping of the extruder. My prints mostly start off very good, but at some random point (@ 11mm z-height yesterday) I start getting a snapping and clicking and I can watch the nozzle jumping up. The print will then go to hell and never recover. It is often at a constant frequency of 2sec. [...] I would appreciate any feedback. I am unable to print anything at this point and it is very frustrating. Thank you.
Re: Extrusion trouble
When my extruder was skipping, I eventually opened the bondtech gear trapdoor and saw that the idler gear was not connected on one side because the pulley shaft had moved out of one end. I hotglued the shaft on both ends and fixed the issue. I would say the idler trapdoor is poorly designed or misprinted, or the pulley shaft I got was too short.
Re: Extrusion trouble
Thank you both for your feedback. I really appreciate the time you took to help me out. I removed the Octoprint RasPi and finally got a good print for the first time in a long time. The second print skipped a bit, but I think the Octoprint is definitely the major factor.