Printing issue  

Re: Printing issue

It would help if you watched it while it was printing during this error.

If the head was moving in the correct place, it might be an extrusion issue (small clog) or slipping knobed gear on the motor, or the filament reel is not unspooling correctly.

If the head is not moving correctly I would check the belts.

Re: Printing issue

I came to the same conclusion, I need to watch the printing during the error.
I will try this today and come back with the result !
Thanks !

Re: Printing issue

Here are two videos showing what happens : the printing starts normally, then some knocking noise generated around the extruder (according to me) appears, leading to some erratic pieces of plastic appearing on the edge of the cylinder, before the print fails.

Long video showing the whole process :

Short video showing the knocking noise :

Re: Printing issue

Things to check:
1) Make sure you don't have too much tension on the screws (14mm with no filament in).
2) Check that the hobbed pulley is attached to the extuder stepper.
3) Make sure the filament unspools evenly.
4) If clogging inside the extruder, maybe drop the temp 5 to 10 deg.

Re: Printing issue

Thanks for the tips !
I will try this next time.

Re: Printing issue

Hello,

I just came back from one week of business trip, back to my printer today.

I tried the following things :

- tension released to 14mm
- pulley perfectly attached to shaft
- filament unspools perfectly, i even modified the support axle to ease the rotation
- new filament spool installed
- temperature dropped to 205
- temperature increased to 225

And whatever I do, i obtain the following result at around 10mm elevation, systematically.

I dont really have any idea on what to check anymore ....

Thanks in advance for your help !

PS: and until 14 days ago, it worked perfectly well !

Re: Printing issue

The only thing I can think of is that you have an intermittent connection in your extruder cable bundle (a crimped zip tie, that with lots of motion has created a bad connection.) Do you by chance have Octopi set up to see the temperature history? Since this is repeatable, can you watch the temperature on the extruder (front panel) as it hits this 10mm mark?

Re: Printing issue

I solved my problem !
I successfully printed again 2 cylinders, one yesterday, one today.
The issue was indeed clogging because of overheating : I had built an enclosure to solve the contact surface issue on bottom of my parts. As this problem was solved, it generated a lot of heat inside of the enclosure, leading to clogging after approximately 1h15 or 10-12mm of printing.
So, I now keep the enclosure around for 45mn, until the bottom has properly cooled down, then I remove the enclosure.
No more knocking noise (=clogging), print is perfect till the top.

Thanks for your help, I did'nt know that extruder overheating could mean clogging !