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HELP!? A new kind of blob?  

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Terence
(@terence)
Active Member
HELP!? A new kind of blob?

Hi all,

I've started printing with a 0.8mm nozzle on my MK3S and have (mostly) fine-tuned it to be giving me reliable prints. I'm making assortment boxes (I take no credit for the design of these as they are completely inspired by Alexandre Chappel on YouTube). I've designed the model so that the wall is made of two perimeters (no infill etc) at 0.6mm height.

I'm very happy with the final quality, however, there are these random big blobs of what looks like burnt filament that appears in some, not all, boxes (see images). All boxes are printed from the same file so unlikely to be anything in the Gcode. Sometimes these blobs end up rolling off the heatbed (not attached to the model), sometimes they end up in the model during printing. I started with the temperature at 240 degrees to account for the larger nozzle and have gradually trialed lowering it until settling on 215C which seems to be working really well (despite the blobs). I've tried to watch the print but of course it never happens when I'm watching.

Does anyone know what is causing this? My print settings are mostly default from the Prusa 0.8mm profile and I've not played with any of the advanced featurwes yet.

Thanks in advance!

Posted : 25/07/2021 2:48 am
Terence
(@terence)
Active Member
Topic starter answered:
Possible Solution

For anyone interested, I think the issue is a leaking hotend.. Upon closer inspection, I noticed some oozing plastic around the hotend, above the nozzle which shouldn't have been there. The colour is the same as the 'blobs' so I think perhaps it was dripping and on occasion dripped onto a print. I'll rebuild my hotend and update if this is the issue.

Posted : 25/07/2021 7:50 am
JoanTabb
(@joantabb)
Moderator
leak

as you have changed the nozzle there is a chance that there is a gap between the nozzle and the heatbreak, causing molten filament to leak over the the top of the heat block 

 

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 : 25/07/2021 7:50 am
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