Prusament PLA partial filament jams, despite correct temperatures.
Hi everyone,
3D printing newbie here I'm just experimenting with my first 3D printer (Prusa Core One+). So far I've successfully printed two models from printables with the printer, however I'm running into issues with my first own design. For some reason the print starts nicely and after some time the filament seems to randomly jam, i.e. the extruder starts knocking and fails to continue to print properly. I find this weird because the model is mostly a uniformly shaped cylinder. The picture below shows two attempts. The first one was created using the Prusament PLA preset from the PrusaSlicer which was set to 230°C for the first layer and 225°C for the rest. After looking around in the troubleshooting section for the Core One, I found that one cause for the jamming could be the nozzle temperature creeping up to high during print. According to the label on the JetBlack PLA Prusament the optimum print temperature is between 205°C and 225°C. So I lowered the setting to 225°C for the first layer and 215°C for the rest. However the 2nd result with the lower temperature (left on the picture) failed even earlier.
I'm wondering if there is an issue with the model, maybe a rookie mistake? However if that was the case I'd expect to see the print to fail much earlier, the model is mostly a uniformly shaped, hollow cylinder. So at the point the printer fails it is basically doing the same thing it has done for many minutes flawlessly.
- Both the printer (factory assembled) and filament are brand new from Prusa so moisture won't be an issue.
- The lower part that is printed properly looks good and is structurally stable.
- I created the model with Blender and exported an STL file
- I imported the STL file and sliced it with Prusa Slicer using the PLA presets mentioned above.
Does anyone have an idea what could cause the issue shown on the picture? For reference I also added the G-Code I sent to the printer (drill_bit_holder_round_120x17_5mm_0.4n_0.15mm_PLA_COREONE_1h43m.bgcode)
RE: Prusament PLA partial filament jams, despite correct temperatures.
Hi Matt! I'm also relatively new to the printing game, but I had a similar problem on my C1. I had a look at your G-Code and it seems like you're experiencing heat creep when changing the Z-layers.
For every layer, the slicer performs a retract on the inner side of the tube, which can cause nozzle clogging. You can probably fix this by reducing the "retraction distance" or by completely disabling "retract on layer change" [Printer Settings → Extruder 1 → scroll down to Retraction].
By the way, if you want to force the layer change and the retraction to happen on the outside of the model, you can change the wall printing order. By default, slicers print inside-out. If you change this setting to 'External perimeters first' [Print Settings → Layers and perimeters → Advanced → it's one of the last checkboxes], the nozzle will start the new layer on the outer wall. This keeps the start/stop points away from the inner hole, leaving the fit for your drill bits perfectly clean.
Let me know if this helped. I hope your print turns out great!🙂
RE: Prusament PETG partial filament jams, despite correct temperatures.
Please double check your printing material.
You mention PETG, but your .bgcode-file and your temperatures are for PLA
RE:
@florima: Thank you for the hints I'll give that a try.
@lw36: Yes that was my bad. I do have a lot of PETG here and plan to use it for printing primarily. But currently I'm still on the filament that came with the Core One+ which is Jet-Black PLA not PETG as I mistakenly stated above. So temperatures and material in the gcode are correct I just confused PETG and PLA in my original post above, sorry for the confusion.
RE: Prusament PLA partial filament jams, despite correct temperatures.
I think I might have narrowed the issue down to chamber temperature and just finished the print, this time without issues (see picture below). I used a nozzle temperature of 220°C (235°C for the initial layer) and 60°C for the bed. It seems that the chamber temperature (with opened top vents) is roughly 10°C above ambient. I do have the advanced air filtration kit installed (which might be partially responsible for the high chamber temperatures). Air filtration is correctly configured in the printer settings. This means the regular chamber fans are disabled. I think that the models I downloaded from printables finished because I printed them before noon when the room ambient temperature was lower. Once I printed the drill bit holder in the afternoon the room ambient temperature was higher probably somewhere between 27 and 29°C. Which means the chamber temperature during the failed prints was probably around 40°C which might be a bit much for PLA. I did bump up the minimum filtration fan RPM from 40% (factory default) to 60%. I'm not sure though that this would have been sufficient to solve the issue. We had a thunderstorm today which means the room ambient temperature was significantly lower today and the chamber stayed below 35°C during the entire print. I wonder, is it a good idea to lower the bed temperature from the preset 60°C to 50°C during print in order to attempt to keep the temperature delta between room ambient and the inside of the printer low?
Does anybody have any advice on how to keep chamber temperatures in check with the advanced air filtration kit installed, except keeping the door open?
@florima: Following your advice I also disabled retract on layer change, maybe this also helped. If I understand the "Minimum travel after retraction" setting correctly, retraction would only be triggered if the head moves across a distance of >=1.5mm without extruding. If that is the case, than for this particular model changing the retraction length would probably have no effect because the head continuously extrudes in a circular motion.
RE: Prusament PLA partial filament jams, despite correct temperatures.
Congratulations!
Awesome, the print looks great! I ran into the exact same issue last year.
Small diameter parts printing way too fast. A few tweaks to those settings fixed it right up for me too.
Due to the chamber temperatur the hotend temperature was not perfect.. Which also can cause heat creeping.
Personally, I wouldn't use a filtration system for PETG and PLA. Maybe you would be able to get better temperature control without the AFS?!
Honestly, the default Prusa profiles usually work great right out of the box. So far, I’ve only really messed around with the Printer Settings and some Filament tweaks (like bridging fan speeds), and I've gotten solid results.
Right now, my biggest headache is dealing with warping on larger PC-Blend parts – but I guess that's just part of the 3D printing game!😂
All the best for your next prints, keep having fun! ☺️
RE: Prusament PLA partial filament jams, despite correct temperatures.
I don't know if it would solve the problem, but this is why I made the Advanced Filtration Dumptruck you'll find in User Mods. I print a lot of PLA and didn't want to be bothered fiddling with the filter unit.
RE: Prusament PLA partial filament jams, despite correct temperatures.
Thanks florima, I got the AFS for the occasional ABS print (I plan on mostly using PETG though which might have less problems with higher chamber temperatures than PLA). While Prusa's AFS modification is relatively easy to one-time-install as permanent mod you unfortunately can not just pop it on and off without removing multiple screws and panels.
Something like Conrad's "Advanced Filtration Dumptruck" that makes switching between AFS and non-AFS operation simple might help though. I suspect such a solution would need some seals and a clip lock mechanism and/or magnets in order to prevent fumes to escape in AFS mode though.