Printer repeatedly stops extruding after about 15 seconds of printing
Has happened the last dozen print attempts. When I cut the strand off and feed a fresh end in I can purge a bunch of filament fine. But when I start the print it at first extrudes fine but then after about 5 seconds it extrudes less and less until it stops extruding entirely at about 15 seconds in and then you can hear the feed motor wheel click as it slips on the filament. I unscrewed the feed tube and pulled it out, this is what that looks like. Have already tried replacing the nozzle, cleaning the hot end, cleaning the gear box, calibrating the first layer height, printing at higher temp. What do you think the problem is? Thanks. Prusa Mini, PLA and PETG
Best Answer by _KaszpiR_:
Iit looks like the three screws that hold the heatbreak in the radiator got loose and the pushingo force from the filament started the heatbreak to move down, making a gap between the PTFE tube and the heatbreak. As the tube is not compressed then the plastic can melt and run to the sidse creating that ring around the filament, then ot gets cold and just blocks the any filament move.
You need to raise it about 5mm probably.
https://help.prusa3d.com/guide/how-to-replace-a-heaterblock-heatbreak-mini-mini_122769#123439 start from 17
You may need to double check the lengh ot the short tube, maybe it is worn out and is just too short already. Moreover make sure the chamfered part is directed downwards, its important because it helps to seal the gap against the heatbreak.
In general you may need to cut and remove the filament, put the short ptfe tube into the top and the ptfe bowden tube from the extruder without screwing it in, then push the heatbreak from the bottom to the point it starts to move the parts on the top a bit.
Screw in the three screws in the radiator. Now you should have enough space to push in the nut on the top, when screwing it in it will compress that short ptfe tube against the heatbreak, making sure there is no area that the melted filament will run out to the sides.
RE:
Iit looks like the three screws that hold the heatbreak in the radiator got loose and the pushingo force from the filament started the heatbreak to move down, making a gap between the PTFE tube and the heatbreak. As the tube is not compressed then the plastic can melt and run to the sidse creating that ring around the filament, then ot gets cold and just blocks the any filament move.
You need to raise it about 5mm probably.
https://help.prusa3d.com/guide/how-to-replace-a-heaterblock-heatbreak-mini-mini_122769#123439 start from 17
You may need to double check the lengh ot the short tube, maybe it is worn out and is just too short already. Moreover make sure the chamfered part is directed downwards, its important because it helps to seal the gap against the heatbreak.
In general you may need to cut and remove the filament, put the short ptfe tube into the top and the ptfe bowden tube from the extruder without screwing it in, then push the heatbreak from the bottom to the point it starts to move the parts on the top a bit.
Screw in the three screws in the radiator. Now you should have enough space to push in the nut on the top, when screwing it in it will compress that short ptfe tube against the heatbreak, making sure there is no area that the melted filament will run out to the sides.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Printer repeatedly stops extruding after about 15 seconds of printing
That did the trick man. I ended up replacing the hot end ptfe tube with a spare one that I had and then followed that procedure to pre-stress the tube. The old tube was a bit melted and I had previously taken it apart and put back together without pre-stressing it when I was troubleshooting the problem. Attached a pic of the old tube (left) and new tube (right) for reference. Thank you!
RE: Printer repeatedly stops extruding after about 15 seconds of printing
Your old tube is clearly messed up, with the bulge on the side and bad ends. I consider them a wear item and replace whenever things start do deteriorate. Order spares. If you buy two spools of Prusa filament, you can add spare parts without the shipping going up, and that seems to be the best shipping to purchase ratio.
Regards,
Mark