Filament twisting during prints
I had this problem with the MK4, although not so bad. However, first few test prints with the MK4s and I can already see I have teh issue again. Filament seems to twist as it goes in to the extruder.
This is a brand new build.
I have tried adjusting the screws in different ways - this does not help.
I have also recalibrated the gears.
Anything else I can try?
Thanks
--> MK4 - MK4S - MINI+ - MMU3 - Accelerometer Guide - BambuLab A1 Combo <--
RE: Filament twisting during prints
I originally had this with my MK4, and addressed it by printing and replacing the idler arm parts myself at .15 structural, which turned out much cleaner than the original MK4 factory parts. I also paid more attention to perfect alignment during assembly of those parts. Obviously in the case of the MK4S, reprinting isn’t an option for some of us due to the more special PA-CF. I can say, however, that the cleanliness of the new extruder parts that came with the upgrade is excellent, at least as good as the ones I’d previously re-printed in PETG.
Thinking about the roller pin alignment in the idler arm, it’s easy to see how the slightest shift in how the two plates are screwed together can have a bigger impact on roller symmetry than adjustments on the idler screws. I only just upgraded mine this last weekend, and haven’t done a long enough print to confirm that mine is perfect yet, but this is how I would approach fixing it. When the idler arm parts are held (but not yet screwed together) there is a tiny bit of sheer movement between them. I would play with that bit of variation, shift it and tighten it in different positions, starting with perfectly aligning the outside surfaces of the printed parts, but then try different positions if the problem persists. Those tiny shifts will be changing the filament roller alignment more significantly, and will hopefully fix your issue.
-J
RE: Filament twisting during prints
Did you ever solve this? I still haven't done any 10+ hour prints to fully test mine, but I've done multiple 6+ hr prints with no twisting whatsoever, so I'm fairly sure mine is good.
-J
RE: Filament twisting during prints
Hi there
I did tighten the two idler screw sin a little further and tried a quick print - results seemed much better. I haven't had a chance to complete a longer print to verify properly yet though - hopefully this weekend!
--> MK4 - MK4S - MINI+ - MMU3 - Accelerometer Guide - BambuLab A1 Combo <--
RE: Filament twisting during prints
9 hours in to a 11 hour print and no twisting!
Seems like its ok now!
--> MK4 - MK4S - MINI+ - MMU3 - Accelerometer Guide - BambuLab A1 Combo <--
RE: Filament twisting during prints
That's great news. Is it the same filament roll you used before? Even back when I had the problem, it was primarily one spool, so I wondered if there might be a non-printer problem going on.
-J
RE: Filament twisting during prints
That's great news. Is it the same filament roll you used before? Even back when I had the problem, it was primarily one spool, so I wondered if there might be a non-printer problem going on.
-J
Now you mention it - no it was a new Prusament PLA spool.........
Saying that, the initial twisting was even with the sample filament included with the printer kit. Was twisting like crazy.
--> MK4 - MK4S - MINI+ - MMU3 - Accelerometer Guide - BambuLab A1 Combo <--
RE: Filament twisting during prints
I’ve been experiencing the same issue since I did the 3.9S upgrade. I’ll give this a try and see if it helps. I thought it was normal for the upgrade.
RE: Filament twisting during prints
You should not be getting any twisting with any duration of print. The design seems sensitive to asymmetries at the idler arm, but it is fixable, as many of us have been able to do. If your extruder parts are the new PC-CF parts, I suspect you'll be able to adjust it out with careful reassembly of the idler arms/bearings, and/or with the tension screws. I say this because the print quality on the PC-CF parts that came with my kit was really good, so I suspect they printed these parts on their A-Team farm printers.
-J
RE: Filament twisting during prints
I found the issue to be the gear box cover screws had worked themselves loose. I tightened them back up and my next print went well with no issues
RE: Filament twisting during prints
This has been happening to me and backing off the idler screws and aligning them seems to have fixed it. Well, 3 hours in so we shall see. 🙂
RE: Filament twisting during prints
I found the issue to be the gear box cover screws had worked themselves loose. I tightened them back up and my next print went well with no issues
I would run a gearbox calibration after tightening the screws as well - just as a check 😉
--> MK4 - MK4S - MINI+ - MMU3 - Accelerometer Guide - BambuLab A1 Combo <--
RE: Filament twisting during prints
24+hours of printing and no twisting! Looks like I had the idler screws too tight and out of alignment.