PTFE Tube keeps clogging  

RE: PTFE Tube keeps clogging

Posted by: @janne-moilanen

Hey,

I've only had the mk3s for a couple of weeks, and the PTFE tube has clogged twice already. I've been printing PLA at 215 and 205 temperatures with print speed of 30. I was just wondering if anyone knows any way to prevent this from happening all the time because it's a pain to change it?

The first clog happened with a 0,40 nozzle and the second with 0,25

The prints I do are usually small and need a lot of precision (Miniatures)

Is it happening at the same spot?  How are you sure it is PTFE tube and not another part of the hotend?

RE: PTFE Tube keeps clogging

 @charles-h13

Yes it always happens at the same spot, just over the ptfe tube and the tube gets filled with filament. It happened a third time now. I've replaced the tube twice now and I have 3 tubes full of filament so my printer is dead (Haven't figured out how to get the filament out of them yet) Here's a picture, so yes I'm pretty sure it's the tube (picture below) 😉

I just want to know what causes this constantly so I could avoid it, kinda impossible to print like this 🙁

RE: PTFE Tube keeps clogging

I am having the same problem now with PC Blend on one printer.  I am going to have to disassemble it tonight.

RE: PTFE Tube keeps clogging

@charles-h13

I found something that might help (At least with the mk3s) with it (see pictures) https://www.thingiverse.com/thing:2975582

So I think I might try to install a extra fan. Just printed out the cooler for the fan since I managed to clear the PTFE tube now, just need to find a suitable fan somewhere. (Luckily it didn't clog when printing the  fan case)

Just somehow this doesn't seem like normal behaviour for the printer so would be nice to know what causes it

RE: PTFE Tube keeps clogging

Hi Janne!

Did this solve your problem? I got a brand new assembled MK3S and when I should start my 3d print and change filament I noticed the big clogg up in the tube.. Will need to start dissassemble it now. Sounds strange for this machine. Had old MK2  for years and all things has happend but newer a clogg going up and puring over the tube..

RE: PTFE Tube keeps clogging

I'm having the same problem. Any way to prevent this?

RE: PTFE Tube keeps clogging

Are you overheating the hotend?  This could be heat creep.  

RE: PTFE Tube keeps clogging

Thanks, it could be because I did do a higher temp to get the first layer to stick. I'll mess around with it

RE: PTFE Tube keeps clogging

@ekmek

I did find early on that if I overheat PLA or PETG to ABS temps that I had an increase in jams.  I think it increased heat creep,  

RE: PTFE Tube keeps clogging

@isak-fpv

Hey (Sorry for the really late answer, seems my spam folder caught all the notifications from prusa) For me it was actually partly my own fault, the first time it clogged was not my own fault, I have no idea why that happened (Guess it just happens sometimes?) But when I dissassembled the extruder to put on a new PTFE tube, I had to take out the extruder fan (I just couldn't get the assembly back in without doing that as it was my first time) And when assembling it back, I put the fan the wrong way around (The sticker goes to the inside, not the outside ;)) Apparently it didn't cool well enough after that. When I noticed it and put the fan the right way around it hasn't clogged since

I do feel like an idiot though! 😉