Print failure. Underextrusion? Clogging?

[Jellicle]

Dear Community,

I'm not entirely new to 3D printing, but it looks like for this issue I would really appreciate your help as I cannot solve it myself.

I'm trying to print an object with PLA with a Prusia i3 replica.

In the beginning it prints fine, but then randomly the printer starts to make a little clicking/bumping sound and the extruded plastic becomes a dashed line instead of a solid one. If I'm present I can push filament through with a hand and it continues fine for some time until it starts all over again.

I tried increasing the temp - decreasing the flow, changing the speed to a crawl for no effect.

The images show prints with this issue happening at different stages.

Could you please give me a hint what can be causing it?

Thank you!

[brian442]

Try increasing the temperature

[Jellicle]

Try increasing the temperature

I've tried upping the temp to 210 and 220 even for this PLA. Will try 225 and see what happens.

[wirlybird]

Check retraction settings. Maybe too aggressive and you are getting a bit of heat creep and partially clogging the hot end.

[Jellicle]

Dear all,

Thank you very much for your ideas. Unfortunately none of them worked so far - I've disabled retraction completely just to check, and tried printing at 240 just for the sake of it - same result:(

Do you have any other ideas that can be looked at?

[dkightley]

Let's short circuit the process of suggesting changes to unknown settings......please attach a factory file so users on here can see what your current settings are.

Load object and profile. File menu==>Save factory file. Attach file with .factory suffix to a post on the thread.

[pixel3design]

I've got same problem many times a long ago.

Failures cames from 3 things:

Filament diameter fluctuation: the tolerance of the filament was too high +/-0.1 ~, remember to buy filament with a tolerance in the range of +/-0.05 ~ or your filament could be bloched into the bowden tube or even in the hotend channel.

Clean your nozzle WHILE hot at least @120° with a guitar string. NEVER clean it up with those ultra tiny drill bits. If you broke one of them in the nozzle, this one could be thrown directly into the dumpster. Guitar strings are made of harmonic steel and if you brake em you can take it out easily.

Don't overheat and hard-retract the same time. This behavior lead to baaaaaad things, like clog. PLA overheated turns into cristallized form. Cristallized PLA became unextrudable and as hard as glass. The only way to get rid of it is cooking the nozzle at really high temperatures, vaporizing it.

hope it helps.

Cheers