Trouble with spring tensioner?
I had an issue with the extruder clicking and grinding filament down inside the gears so I followed the directions to clean out the extruder assembly, but now it won't lead filament! I read about the "spring tensioner" but this isn't pointed out in the directions so I'm trying to figure out which screw this refers to. Is it the screw pointed out in Step 12 that shouldn't be over tightened? I can feed the filament through manually with the screw out, but it won't work with that screw in at any depth. Should the screw be loose? About how many CCW turns from finger tight should it be?
Best Answer by Crawlerin:
It's extruder idler spring: https://help.prusa3d.com/en/article/clogged-nozzle-hotend-mini_112011
RE: Trouble with spring tensioner?
It's extruder idler spring: https://help.prusa3d.com/en/article/clogged-nozzle-hotend-mini_112011
RE: Trouble with spring tensioner?
@crawlerin
Thanks! Weird that they mention that on the hot end troubleshooting page and not on the extruder page! Now I have a new problem, I kept loosening the tensioner screw until it came out and getting it back in with the screw pushing back is proving difficult! I'm going to have to wait til I can get another set of hands to help me so the whole printer doesn't slide away as I put pressure on the screw!
RE: Trouble with spring tensioner?
@garylzimmer
I am glad it cleared it up for you. As for trying to get it back in - it is best to do that with filament unloaded, but maybe you can try to squeeze extruder assembly between thumb and fingers of one hand and push screw in with another. Providing you can get both hands in there, it may be hard if you have it in enclosure.
RE: Trouble with spring tensioner?
@crawlerin
Thanks for your continued help! I eventually got it by using this guide written by bstricker on the first page I linked:
"I just did this process this evening and this is what worked for me:
1) Turn unit off2) Completely undo the screw with the spring in it holding the idler tension arm 3) Push filament up until it stops like you are going to load4) Now, open the gear cover up, and MANUALLY turn the gear wheel with your finger until filament starts feeding through5) You'll see a bit of a gap between the tension arm and the extruder body6) Screw the spring tensioner screw back in leaving that much gap7) Manually feed filament through again and make sure it doesn't click and that it grabs hold as it should - confirm it feeds through to the PTFE tube8) Manually back out the filament and you should be good to go to have the printer feed it automatically.Hope this helps, I've been struggling with this for a few days myself."
My question from that though is "what is the tension arm and where is it?" I'm not sure I know where to find this gap that I'm supposed to be monitoring. Thanks!
RE: Trouble with spring tensioner?
@garylzimmer
It's right opposite of the screw on picture above, under brass coupler. It is where the screw you just adjusted screws in, there's a bearing in it that pushes filament against extruder gear's teeth. If you push filament in, that plastic part protrudes. It's this one:
https://github.com/prusa3d/Original-Prusa-MINI/blob/master/STL/MINI-extruder-idler.stl