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Clumping and nothing printing - PETG and PLA  

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Mike Dean
(@mike-dean)
Active Member
Clumping and nothing printing - PETG and PLA

I have been successfully printing with PLA for 18 months and have requirement to print PETG.  I successfully printed some tests with PETG but had problems printing larger parts, so I thought perhaps the PETG had sat out in my office for a month and might have gotten moist.  Also, adhesion was NOT very good (going to powdered sheet since adhesion is supposed to be TOO good on smooth). Bought a SUNLU dehydrator and baked it at 50 C for 6 hours, and then tried again.  At this point, got immediate problems.  The print laid down the test / discard strip and then when it went to print nothing came out onto the bed, and filament clumped around the nozzle immediately.  After several attempts with brass brush and acupuncture in between, no differences.  I verified that if I feed filament, it freely comes through.  Again, the discard stripe lays down but then nothing.

I decided to go back to PLA since that has been working.  Changed the filament at the PETG temperatures, set up for test print, and the PLA is doing the same thing.

Opened the extruder and assumed that I had some kind of blockage, so used method 1 with an Allen wrench and pushed it into the tube;  followed with PLA.  Again, filament flows smoothly but it seems to clump up around the nozzle.  There was nothing obvious in the extruder - filament, etc.  

When I "load filament", the extruder makes ugly noise while it is in the fast speed, though filament comes through.  No ugly noises during print attempts.

I have leveled the bed with a variance of 0.02 and the bed visualizer in Octoprint shows beautiful leveling.I have tried live Z but given that the discard laid down, and then nothing laid down, I varied the live Z plus or minus 100 from previously working settings with no effect.

Any advice would be welcome.  I have ordered silicone socks which will arrive on weekend, but since even the PLA is now clumping, I am dubious this will solve problem.  And by the way, I even tried a brand new spool of PLA (unopened) from Prusa, and same problem.

Thanks.

Posted : 19/01/2023 12:15 am
Diem
 Diem
(@diem)
Illustrious Member

You may have a worn or damaged nozzle, have you changed yours or are you still on your first?  9 - 12 months of heavy PLA use is enough to cause degredation.

Cheerio,

Posted : 19/01/2023 12:34 am
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA

While I have printed for over 18 months, very sporadic.  Total print time in statistics is 3 days, and I have consumed about 5kg of PLA.  

I think that with a firmware update, etc. that I may be FAR too high, so will try complete reset procedures, etc.  Thanks.

Posted : 19/01/2023 1:49 pm
Diem
 Diem
(@diem)
Illustrious Member

With low useage, I wonder if your print sheet has picked up some contamination.  Clean the sheet with dishwashing detergent (Dawn/Fairy) and plenty of HOT water, rinse well and dry with a fresh paper towel. Handle by the edges only.

Cheerio,

Posted : 19/01/2023 2:37 pm
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA

I did factory reset and went through entire wizard without any problems, EXCEPT that when I was told to insert the filament and do the test print the same behavior occurred, with following result.  This was with the live z starting at zero;  I messed around with it, but since it started out perhaps too high, doesn't making a negative mm live z adjustment make the situation worse?  If I am starting out too high, despite the calibration procedure, then I am not sure what to do.

Perhaps my initial 18 months of printing was beginner's luck!  I am clearly still a beginner.

Posted : 19/01/2023 3:14 pm
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA Resolved

I finally just got the z live adjustment corrected.  Printing in PLA.  Will get socks before resuming PETG attempt.  I think the PETG clumping is from its nature and lack of a sock;  the subsequent PLA clumping was because I did a firmware update and a lot of bed leveling without realizing that it had considerably altered the geometry, and I was way high.  Sorry for the distraction.

Posted : 19/01/2023 5:35 pm
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA

This was also done and coincided with beginning to get success.  Thanks!

Posted : 19/01/2023 5:36 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Clumping and nothing printing - PETG and PLA

Hi Mike, did you change the nozzle, if so, which type of nozzle did you use?

regards Joan

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 19/01/2023 5:53 pm
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA

I did not change the nozzle. I also discovered that it is non-trivial to put on a sock because of the way I routed the wiring.  In any case, after getting the z level low enough, everything resolved and I printed PLA without problems.  I then switched to the powdered sheet and increased the offset by almost -300, and am printing in PETG without problems.  

I think the big problem is switching back to PLA and then encountering clumping, but I see little reason to switch back if I can successfully and reliably print PETG.  The price is no longer much different.

No new nozzle.  Sorry.

- Mike

Posted : 23/01/2023 12:59 am
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA

Problem resumed, unable to print anything.  Either no adhesion or else PETG clumping on nozzle.  Have been advised to try hair spray on the powdered PEI sheet, and am going to install new nozzle.

Posted : 02/02/2023 6:38 pm
Mike Dean
(@mike-dean)
Active Member
Topic starter answered:
RE: Clumping and nothing printing - PETG and PLA

New nozzle (probably not necessary since the old one looked fine after I got it off), silicone sock, and hairspray.  Silicone sock critical, I think, as the PETG could not goop up on itself.  I have the blue sock that only lets the tip of the nozzle through - beware that another company sells a sock that exposes the whole nozzle head and only protects the rest of the heat block, which would NOT have solved the problem.

Posted : 06/02/2023 12:27 am
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