My Printer (Lulzbot Mini) stops extruding while printing

[diinnah]

I use PLA for my prints, my problem started when my nozzle clogged I had to remove it and unclog it, afterwards every time I start a print I have to press down on the filament right before it starts printing because the filament automatically retracts and stops extruding. Now another problem came up; it stops extruding and also the filament retracts while printing and doesn’t finish my print.
I’m really confused and sad, it’s a new printer and thought will have no issues with highly reviewed printer like mine.

Hope anybody can help me
Dina

[User_4740]

hi Dina, the first thing to do is to check the nozzle temperature, is it reachin 220Deg C?

if it is a mini lulzbot i assume the feeder is in the nozzle-head assembly are you able to feel the filament feeding it?

[keebie81]

Are you using the default cura profiles? Sounds like retraction might be set to high. You can always call tech support, I believe they are 24hrs

[stopaginn]

Dina,

when this has occurred for me, it’s a temperature issue. increase the hot end temperature. Tell the print software to extrude. Monitor the flow. You want to make sure the flow move freely. You can also turn the main extrusion gear and feel the resistance. It shouldn’t push back or feel springy.

Jim

[diinnah]

Hi, The temperature is set on 220Deg, the problem is it works sometimes, but I always have to push the filament down when it reaches 190Deg and once I push it down it starts to extrude a lot of PLA until it starts to move to drawing my shape, but sometimes it continues normally until it finish and sometimes stops extruding after building two layers.

[diinnah]

kindly check my settings, maybe there is something wrong with my settings and I did not notice. I attached the picture

[keebie81]

Could you attach a picture showing it fail after two layers?

when it autolevels do any of the corners deflect down? Maybe the nozzle is dirty and autolevel not working correctly so first few layers too close causing filament to grind.

[diinnah]

I think if it was the problem of a clogged or unclean nozzle, it would have failed all the times, while it finish my shapes sometimes and fails other times. Right?
Can this be related to changing the nozzle from 0.5 to 0.25, like for example the nozzle is not compatible with the printer and causing these problems?

[diinnah]

can the gear alone be replaced? I think maybe it’s the gear that is turning backwards. If this is the case how can I fix it?

[keebie81]

Why didn’t you say that to begin with? A 0.25 nozzle is going to require a lot more pressure to push filament through the nozzle. You need to slow down your print speeds a lot.

Put back a 0.5nozzle and see if that solves it.

[diinnah]

I didn’t know that would be an issue, thanks for helping

[stopaginn]

Dina,

yes, it’s the nozzle size. The smaller hole makes it hard for the filament to push through. The only solution is to increase the temp and slow the print movement down.

[ruggb]

info: Nozzles clog because the filament is melting too soon in the hotend - period…

This can be caused by:

1. insufficient cooling of the hotend heatsink
2. too much retraction causing warm filament to be pulled back into the upper hotend.
3. too high a temp on the hotend vs the print speed.
4. misdirected cooling to the nozzle instead of the heatsink.

Once it becomes soft and you shut it down, you have a clog because a reheat won’t dislodge the stuck filament at the top.

Do not confuse nozzle clogging with insufficient extrusion.
If the temp is not sufficient for the nozzle size and print speed, the filament will not melt fast enough to be extruded.

All of these settings are a function of the operator and not the printer. 3D printers are not plug-n-play. This is not a problem you can blame on the printer. You must get the settings right for each print.