PLA Sticking Too Much to PEI Sheet  

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Classic
(@classic)
Active Member

Hi All,

A couple of hours ago, I cracked open a new roll of Prusament Jet Black PLA, loaded it into the printer and did a first layer calibration. I used my smooth PEI sheet that I had put away for a couple of weeks while I printed some PETG, cleaning it with windex before printing. When I went to remove the test lines from the bed, they were really stuck!

This came as a complete shock to me. I've heard of prints not sticking well enough to the bed before, but PLA sticking too much? Never. Nor have I had any issues with Matterhackers PLA or the test Prusament that came with the printer. My mini is on firmware 4.0.5 with the Bondtech heatbreak and SPINDA installed as well. 

I know I can use a release agent, but for the moment I'd prefer to get to the bottom of this. I'm wondering if I had my nozzle too close for comfort. If anyone has any ideas as to why this might be happening or what to do about it, that would be much appreciated.

Thanks! 

Best Answer by LeeM:

@classic

Maybe there was a slight residue of PETG that mixed with the PLA when running first layer calibration (I've seen similar after switching from PETG to PLA) ?

This topic was modified 2 months ago by Classic
Posted : 11/02/2021 8:51 pm
Diem
 Diem
(@diem)
Reputable Member

First thought:

When you sliced your part - you did change the filament setting from PETG to PLA?

Cheerio,

Posted : 12/02/2021 6:31 am
Classic
(@classic)
Active Member

@diem

That's the funny thing, I didn't do any slicing, I just ran the first layer calibration from the calibration menu. `\_🙃_/`. I did some more printing afterwards and I couldn't reproduce the problem. There are still some lines that appear to be indents on my steel sheet, so I'm going to assume that I had my live z value too low and call it a day. Thanks for the idea, though!

Posted : 14/02/2021 6:02 pm
LeeM
 LeeM
(@leem)
Eminent Member

@classic

Maybe there was a slight residue of PETG that mixed with the PLA when running first layer calibration (I've seen similar after switching from PETG to PLA) ?

Posted : 15/02/2021 2:53 pm
Classic
(@classic)
Active Member

@leem

You know, that sounds like a greater possibility. Thanks for the comment and heads up! I'll keep this in mind the next time I switch from PETG to PLA, and probably do some extra purges or a first layer calibration on the textured sheet before moving to the PEI. Thanks again. 

Posted : 17/02/2021 10:38 pm
mark
 mark
(@mark-6)
Estimable Member

@classic

I always do a cold pull or two when going from a hotter temperature filament to a lower temperature one. I use the lower temperature filament for the cold pull, but heat it to the higher temperature filament's high temperature, then cool down and pull. That seems to loosen any remaining high temperature filament and stick it to the low temperature one when pulling. Otherwise, it seems that bits of the high temperature filament stay in the extruder head when it is only heated to the lower temperature.

Regards,

Mark

 

Posted : 18/02/2021 4:39 am
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