How to remove buildup in heatbreak?
So I've recently discovered that the PTFE tube that came factory installed with my mini is over a millimeter too short! (I think other people are finding this as well). Because of this filament has worked its way under the tube and formed a bit of a plug (not a complete plug though), I'm looking for advice on how to remove it. I'm thinking of soaking the hotend/heatbreak in acetone? I can't really push it through so to speak as it's not in the path of the ptfe tube. Advice here would be appreciated.
RE: How to remove buildup in heatbreak?
Hello, I had the same problem. You can try for removing the "Atomic Method" and in my case the spare-part tube was long enough.
RE: How to remove buildup in heatbreak?
This has happened to me twice now. I think the latest rebuild is going to work for a while. I'm less convinced that having a PTFE tube that is the exact length needed is as important has having a good compression between the hot end assembly and the brass fitting that holds the tube. In my case, I took the heatbreak out and heated it with a torch (gently) until the material inside softened. I used a piece of filament to dab the material and lift it out. Repeat until clean. I then assembled the hot end in accordance with Prusa directions. The only exception was instead of loosening the brass fitting a quarter turn, I did a half turn. This adds a little more compression when tightening it down in the final step. So far, it is working well for me. This last clean/rebuild was about a month ago and no issues so far.
RE: How to remove buildup in heatbreak?
Like Holger mentioned, do a cold/atomic pull with the PTFE liner removed.
Example @ Timestamp 2:20:
More reading: https://all3dp.com/2/3d-printer-clogged-nozzle-how-to-perform-a-cold-atomic-pull/
I use eSun cleaning filament to do my cold pulls and it works super well.
RE: How to remove buildup in heatbreak?
I dug it out this time and it seems to be working so far. Hopefully I don't get more issues. Thanks for all the advice!