ABS extrudes fine, PLA comes out all squiggly with clicks. I'm baffled.

[mikem77]

I'm baffled with debugging this problem on my 1-month old Flashforge Creator. Bottomline is that extruded PLA comes out a squiggly mess, but ABS extrudes/prints just fine. This is when attempting a print or just when extruding during loading (with the bed nowhere near the nozzle). This is when trying with BOTH extruders.

PLA does seem to extrude normally at very high temps (like 230+ degrees). At 220 degrees or lower, it is all squiggly. I've tried two different brands of PLA-- a "Prototype Supply" brand which comes highly recommended on other forums as well as an off-brand.

I have completely disassembled the extruders twice now in trying to solve the problem. I've taken off nozzles. Soaked them in acetone. Cleaned them out with a thin wire strand. Replaced PFTE tubes with the extras that came with. The nozzles are clean. Really clean. I've cleaned the extruder wheels with a razor blade, etc.

While I'm only a few weeks into 3d printing, I have considered these issues and why I don't think they are issues:

1) partial extruder clog. I've thoroughly cleaned nozzles twice and ABS prints fine.

2) bad filament. Prototype Supply (toybuilders amazon) could be bad. But my other off-brand PLA behaves the same way.

3) Build plate is not level. First, ABS prints fine. Second, even when extruding during loading (when the bed is nowhere near the nozzle), I see the squiggly extrusion with the PLA but non-squiggly extrusion with PLA.

4) Bad temperature monitoring. Perhaps my temps are 10-20 degrees too low and that I'm just too low with PLA and just on the edge of ABS. If this were the case, then I'd have a bad thermocouple on *both* extruders.

Any other ideas? I'm baffled.

[richardphat]

What I learnt from my experiences, dont buy filaments cheap filaments, especially manufactured from china. Piss poor quality control, diameter of filaments never consistent, liquid vapor coming out from filaments that irritates your eyes .....
Have you tried PLA filaments from ColorFabb? If yes, do you still have the same problem?

You also forget the colour, not everyone use same pigment for the same colour. You can bump from 200C to 240C if you randomly picked a colour.

[Marm]

Excuse my naivety, but if it extrudes at 240+ fine, why not run it there?

[Mjolinor]

You do not need to be concerned about it being "squiggly" as you extrude with nothing underneath, it will generally not affect the printing as the head squishes the new plastic between itself and either plastic underneath or the bed. When new most nozzles will extrude a nice straight piece of filament but once you start messing with the end trying to stop it being squiggly you are more likely top damage it further than you are to cure it.

[Serena]

Maybe post a little video of it? That may help determine the problem. I wonder if it's an issue of getting the PLA to stick and lay down on the bed? It's hard to say without seeing it. Pictures or video would help.