Large ABS + PLA print, PLA keeps clogging
Howdy, y'all!
I recently got a Prusa XL with 2 tool heads and the Prusa enclosure. I've done some initial multi-material prints to verify correct functionality, such as the 2 color keychain that came with the printer.
The whole reason I got this printer was to use multi-material printing to make support removal easier. Most of my projects are in ABS, and most of my research suggests using PLA as the interface material will lead to easy removal. I've setup Prusa slicer to use the PLA at the interface, and it appears to slice correctly. However, when I actually start to print, the PLA extruder constantly clogs. The clog detection works as intended, it is actually clogging every ~2 layers. The extruder gear starts grinding and jumping. I have tried using different PLA and snipping the ends while re-loading. The bits that did print separated flawlessly, so at least the concept works. The ABS head has been printing flawlessly.
Any suggestions? Thanks for any help.
The extruder gear starts grinding and jumping.
The three most likely causes:
- Out of spec filament - over or undersize or not round in cross section.
- Remains of a previous problem filament clogging the teeth of the extruder gear.
- Wrong pressure setting on the extruder idler - did you change for a soft or undersized filament and forget to change back?
As you have tried changing filament the most likely is powdery remains clogging the gear teeth, open the idler and blow/brush clean.
Hmmm, there's also a very slight chance of contamination - dust/grease on the spooled filament.
Cheerio,
RE: Large ABS + PLA print, PLA keeps clogging
The extruder gear starts grinding and jumping.
The three most likely causes:
- Out of spec filament - over or undersize or not round in cross section.
- Remains of a previous problem filament clogging the teeth of the extruder gear.
- Wrong pressure setting on the extruder idler - did you change for a soft or undersized filament and forget to change back?
As you have tried changing filament the most likely is powdery remains clogging the gear teeth, open the idler and blow/brush clean.
Hmmm, there's also a very slight chance of contamination - dust/grease on the spooled filament.
Cheerio,
First off, thanks for the suggestions, I appreciate the input.
1. The filament is Prusament PLA, and I used it previously without incident. I also tried multiple spools with the same results. I previously ran some PETG through the system without these issues too. What's the best way to check size and roundness so I can verify?
2. I don't see anything in the gear when I open the tensioner, what's the best way to spin the gear so I can inspect all of it?
3. For the idler tension, do I turn the screws in more for a more flexible filament? They are mostly out right now, as delivered from Prusa. I think the PLA is heating up because of the bed temp increasing the extruder overall internal enclosed environment temp, leading the PLA to be more flexible or more soft. (or both)
What's the best way to check size and roundness so I can verify?
Micrometer. Roll a very short, straight, offcut under your fingertip.
what's the best way to spin the gear
On the LED menu: Control > Move axis > E
I previously ran some PETG
OK, in case of residue try a cold pull - same menu, further down.
do I turn the screws in more for a more flexible filament?
See: https://help.prusa3d.com/article/flexible-materials_2057
Cheerio,
RE: Large ABS + PLA print, PLA keeps clogging
Howdy, y'all!
I recently got a Prusa XL with 2 tool heads and the Prusa enclosure. I've done some initial multi-material prints to verify correct functionality, such as the 2 color keychain that came with the printer.
The whole reason I got this printer was to use multi-material printing to make support removal easier. Most of my projects are in ABS, and most of my research suggests using PLA as the interface material will lead to easy removal. I've setup Prusa slicer to use the PLA at the interface, and it appears to slice correctly. However, when I actually start to print, the PLA extruder constantly clogs. The clog detection works as intended, it is actually clogging every ~2 layers. The extruder gear starts grinding and jumping. I have tried using different PLA and snipping the ends while re-loading. The bits that did print separated flawlessly, so at least the concept works. The ABS head has been printing flawlessly.
Any suggestions? Thanks for any help.
I experienced a similar issue with the combo of ASA/ABS with PLA as support material. I concluded the issue was driven by heat creep due to the elevated enclosure temperature causing reduced extruder cooling followed PLA softening too far up the nozzle lead. I resolved this by switching to a higher temp support material when printing ASA/ABS. PETG, PA, and HIPS are all options I have used successfully with different compromises. PETG is easy to use and print, but has the worst separation performance to the point of leaving behind visible marks or bits of material to pick out. PA has excellent and clean separation but small islands of material don't always adhere well while printing onto supports. HIPS is probably the best overall performer (and can theoretically be dissolved in d-Limonene though I haven't tested this) but is the least common and unlikely to be part of your current suite of materials.