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John
 John
(@john-34)
Eminent Member
Strange circle blemishes on top layer

Hi all,

 

So this just started today on a couple prints. I’m seeing these strange circle artifacts on my top layer ... although did see one on a bottom layer. Never seen anything like it and not quite sure what to make of it!

 

This is on my MK3S printing with whatever filament comes with it (no brand noted). Temp 220, bed 70, 0.20 Quality preset, gyroid infill 15%. 

 

Posted : 20/03/2020 7:40 am
RH_Dreambox
(@rh_dreambox)
Prominent Member
RE: Strange circle blemishes on top layer

The printer does not make circular designs unless they are in your gcode. If you inspect the different layers in the slicer program, you should see them there. These may be residues of geometries that have been removed or hidden incorrectly.
Please upload the file here so we can inspect it.

Bear MK3 with Bondtech extruder

Posted : 20/03/2020 10:43 am
bobstro
(@bobstro)
Illustrious Member
RE: Strange circle blemishes on top layer

Are you seeing this with other prints? Or only this part? Does it happen repeatedly with this part?

Zip and upload a copy of your 3MF project file. This is not something the slicer will usually do, and being able to inspect your part and settings will allow us to make better suggestions.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 20/03/2020 2:22 pm
John
 John
(@john-34)
Eminent Member
Topic starter answered:
RE: Strange circle blemishes on top layer

Thanks for your responses!

I only saw this on the first layer of one other print. That I could understand as maybe there was a bit of something on the bed, etc etc. But the top layer is so strange. This is the first time I've seen it with this part, although this was a new .gcode as I added another part to the plate (which printed fine). 

Please find the attached .3mf file -- I don't see the artifact there:

BaseArms

Posted : 20/03/2020 5:22 pm
bobstro
(@bobstro)
Illustrious Member
RE: Strange circle blemishes on top layer

Hmm. Nothing obvious in the 3MF. You say you saw it on another print? Try the same print on the other side of the PEI surface, perhaps? Looks like this will be something difficult to reproduce.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 20/03/2020 5:38 pm
John
 John
(@john-34)
Eminent Member
Topic starter answered:
RE: Strange circle blemishes on top layer

Yep I think you’re right. 

I’m going to print it again - just the part with the problem - and see what happens. Very very strange. 

thanks for looking!

Posted : 20/03/2020 5:44 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Strange circle blemishes on top layer

the Filament Must have been made from Corn...
these are Crop Circles! Lol...

 

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 : 20/03/2020 6:27 pm
vintagepc
(@vintagepc)
Member
RE: Strange circle blemishes on top layer

Fingerprints on the bed causing lifting and warping? Long shot, but if it isn't shown in the g-code...

Posted : 20/03/2020 6:32 pm
nilok
(@nilok)
Estimable Member
RE: Strange circle blemishes on top layer

@vintagepc

They actually look like fingerprints now that you mention it.....

Is your printer grinding? Bearings squeaking? Motors smoking?
Step 1) Wash your Steel Sheet
Step 2) Return to Step 1

Posted : 20/03/2020 6:37 pm
John
 John
(@john-34)
Eminent Member
Topic starter answered:
RE: Strange circle blemishes on top layer
Posted by: @nilok

@vintagepc

They actually look like fingerprints now that you mention it.....

Ha ha kinda yeah, but on the top without touching it at all? And they are perfect little circles .. 

Posted : 20/03/2020 6:52 pm
John
 John
(@john-34)
Eminent Member
Topic starter answered:
RE: Strange circle blemishes on top layer

Ok now I’m seeing it on two different (but similar) models, around the same area  but not the exact same spot. 

To be clear, this is on a clean bed and I have not “touched” the print in any way. It’s not a fingerprint and it doesn’t show up in the gcode, AND didn’t happen before yesterday on this same model. 

See pics:

https://photos.app.goo.gl/R61TGpu3nEt9dzFW8

Posted : 21/03/2020 12:31 am
bobstro
(@bobstro)
Illustrious Member
RE: Strange circle blemishes on top layer

Try same model rotated on same spot. If circles move with part, it's something in the print. If circles stay at same spot but appear in new section, it's something on the bed or hardware. Maybe. 

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 21/03/2020 1:18 am
John
 John
(@john-34)
Eminent Member
Topic starter answered:
RE: Strange circle blemishes on top layer
Posted by: @bobstro

Try same model rotated on same spot. If circles move with part, it's something in the print. If circles stay at same spot but appear in new section, it's something on the bed or hardware. Maybe. 

Good thought

Posted : 21/03/2020 2:28 am
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