Sticky residue buildup in PTFE Tube

Submitted ⁨⁨1⁩ ⁨year⁩ ago⁩ by ⁨zevrant@lemm.ee⁩ to ⁨3dprinting@lemmy.world⁩

Trying to reduce the amount of constant maintenance the my ender 3 printers require and one of the biggest issues i’m having is a buildup of sticky residue inside the ptfe tube inside the hotend/ptfe tube. It’s not leaking as i visually inspect before cleaning and i can see where the tube connects and there’s a clear line and no visible signs of leakage. Usually some rubbing alcohol and a scrub brush will fix the issue for about 100hours of print time before needing to clean it again.

I’m wondering if i might need to reduce the flow rate on the printers or maybe i’m missing something. Running this with a direct drive extruder so the ptfe tube is pretty short and since the residue is building up inside the heater and nozzle too i don’t think that’s the issue.

Things i have tried:

less heat printing at 200 instead of 205 - marginal / no difference
printing speed turned down to 20mm/s - it takes longer for the buildup to become an issue but it also takes as long for the prints to complete
lowered retraction distance i thought the high retraction distance might be causing issues, while it made it better now i have stringing to deal with

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rambos@lemmy.world ⁨1⁩ ⁨year⁩ ago
BTW if you didn’t mod your printer you don’t have direct drive. Bowden tube is not long, but its still bowden setup. I’m not sure what sticky thing is, but it can be filament, PTFE or dust (on the outside of your filament - you can guide filament trough some kind of sponge to clean it before extruder). Nothing else should be there. If reducing retractions fixed the problem you might check your hotend fan. For high retractions you need proper cooling to avoid heat creep (assuming thats the problem). Not having all metal hotend with heat break makes it much harder ofc. What retraction settings do you use (now and before)?

You can also reduce stringing by increasing travel speed, using lower temps and smaller nozzle.

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- rambos@lemmy.world ⁨1⁩ ⁨year⁩ ago
  Just make sure you didn’t melt PTFE since its kinda unhealthy
  
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  - Uranium_Green@sh.itjust.works ⁨1⁩ ⁨year⁩ ago
    I want to say PTFE starts to become a problem around 240C, so it shouldn’t be that, but this advice is useful.
    
    I’m curious as to what filament OP is using and if they’ve got a picture of the residue…
    
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solarbird@kbin.social ⁨1⁩ ⁨year⁩ ago
Y'know just in general I really strongly recommend going all-metal or better bimetallic on your hot end? It cleared up so many problems for me. The Ender 3-series hotends really aren't bad if you just back that PTFE up a bit.

I like this one (no affiliation other than I bought one) quite a lot, and I got it on sale so it was cheaper than the current price. But even at the current price I'd definitely say it's still worth it.

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