Gaps/zits especially on circular objects  

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thomas.b13
(@thomas-b13)
Eminent Member

Hi

Been getting the below recently especially on circular objects. On some objects if I set z seam to aligned its better however its one long noticeable line, that looks like a gap/under extrusion. 

Initially I thought it was the filament however its doing it on all my filaments now (current esun pla+).

Is this more likely to be skipped/missed steps? My idler screw is flush with the plastic (the outside part) so not sure if its that. When pulling on the idler part should it be fairly tight/difficult to move or should there be some movement?

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Posted : 17/05/2020 4:58 pm
jweaver
(@jweaver)
Honorable Member

Its the seem.. where the layer change is happening.

there are ways to change the behavour (ie make the change happen at the same point or in different places per layer, but its a side effect of FDM printing.

Posted : 17/05/2020 5:36 pm
thomas.b13
(@thomas-b13)
Eminent Member

I'm not sure it is as I see the zits/gaps on what looks like the exact same layer. that first photo was near, the second aligned, no difference looks the same.

I'm thinking this is a new issue now, and not z seam as before, although I admit when I've been changing the z seam in prusa slicer its still terrible compared to my other printers, maybe its just the mini or the slicer as my other printers the seam is almost invisible. 

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Posted : 17/05/2020 7:33 pm
Karl Herbert
(@karl-herbert)
Famed Member

@thomas-b13

With circles a quantity of data is transmitted, It could be timeouts, which could be caused by either the firmware or a possibly connected server.

I had this problem with my MK3 when I enabled serial logging in octoprint.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 17/05/2020 8:48 pm
Stephen
 ste
(@ste)
Active Member

I have been getting every similar problems still never got to the end of it sadly. Running different tests now. Have you printed the same object twice? Only asking because for me there are always in the same spot but sometimes different in number .

Also do you get any popping sounds?

 

This post was modified 5 months ago by Stephen
Posted : 06/06/2020 4:50 pm
Texy
 texy
(@texy)
Reputable Member

I have the same issue, but it’s not restricted to circular objects. I also get the popping sound. I’ve tried doing the filament too. Some filaments are worse than others. 
Texy

Posted : 07/06/2020 6:38 am
thomas.b13
(@thomas-b13)
Eminent Member

I’ve tried the same object multiple times. Any circular object and it turns out like that really. No popping sounds, I know it’s not the filament as it’s brand new, plus it works fine on my other machines. I have also tried multiple filaments and it’s the same.

@karl-herbert I was thinking it could be a timeout issue. Switched back to the usb Prusa supplied and the same issue. Not sure how I could tell if it’s firmware?
I’ve not printed on my mini for a while because of this issue but may go back to it.

I’m still not 100% sure what the issue is, I’m going to print the above with zero retraction, see what it looks like.

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Posted : 07/06/2020 10:07 am
Oxygen
(@oxygen)
Estimable Member

I have tried to print a simple circular object, the seem is visible (in slicer set to aligned) printed in PLA at 0.2mm speed

Mini with FW:4.2.1 + Bondtech Heatbreak...
Posted : 07/06/2020 12:40 pm
thomas.b13
(@thomas-b13)
Eminent Member

Did some more testing and took a photo for comparison, attached. 

Going from left to right:

1. Seam: Aligned Retraction: 3.2mm Z Lift: Off

2. Seam: Aligned Retraction: Off Z Lift: Off

3. Seam: Random Retraction 3.2mm Lift: On

Number 2, the middle one is a lot better, nice and smooth apart from the top/bottom being a mess because of no retraction. For me if retraction is completely turned off and seam aligned the outer perimeter is a lot better.

I must be missing something, this just doesn't seem right to me. 

Never had this with other printers/direct drive and the filaments are all fine in other machines. I'm going to try the print again with the seam set as aligned and retraction/lift as normal with some prusament I bought to see if it acts differently with prusa filament. 

This post was modified 5 months ago by thomas.b13
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Posted : 10/06/2020 9:41 pm
Chin
 chin
(@chin)
New Member

@thomas-b13
Could you post a picture with your changed Settings in the Prusaslicer? Mine is in a different language and I have trouble finding the right collumn.
Ty 🙂

Posted : 11/06/2020 8:36 am
thomas.b13
(@thomas-b13)
Eminent Member

@oxygen

Definitely better than what I've been getting, the seam is still not great though when I compare to my other printers,  must just be the mini. 

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Posted : 11/06/2020 12:18 pm
Oxygen
(@oxygen)
Estimable Member

shall I share the STL and GCODE file so you can compare the results? I have a Bondtech heatbreak

Mini with FW:4.2.1 + Bondtech Heatbreak...
Posted : 11/06/2020 1:00 pm
thomas.b13
(@thomas-b13)
Eminent Member

@oxygen

That would be useful yeah, just to see what its like. I did not know bondtech did a heat break for the mini, I might just get one. 

I have bondtech on my Wanhao I3 and Raise N1, just seen they do an extruder upgrade kit for the mini also!

https://www.3djake.uk/bondtech/prusa-mini-extruder-upgrade-kit  

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Posted : 11/06/2020 1:58 pm
Oxygen
(@oxygen)
Estimable Member

tubetest_STL_and_GCODE these are the requested files

Mini with FW:4.2.1 + Bondtech Heatbreak...
Posted : 11/06/2020 3:37 pm
Oxygen
(@oxygen)
Estimable Member

Let me emphasize I have chosen to buy the heatbreak and try to solve problems I had with the original part, you mileage may vary... I will not take the blame if your issues are not solved.

Mini with FW:4.2.1 + Bondtech Heatbreak...
Posted : 11/06/2020 3:41 pm
thomas.b13
(@thomas-b13)
Eminent Member

@oxygen

Oh I know and I would never blame anyone, this is 3d printing after all. I like to upgrade where I can anyway as with all my other printers. I went ahead and got the bondtech extruder, no difference after that, didn't really expect it to be. I've got the heatbreak but not installed yet, I will test after that also. 

Again, I doubt it will fix it but you never know. I'm printing that gcode file you provided just now, will see what that turns out like. 

I decided to print something rectangular, a small piece and those blobs/zits are all over similar to the above photos. I then switched filament to filamentive matt black and while there are fewer artifacts there are still too many for me to be happy with it. 

I have a feeling if I turn off retraction again they will disappear, but that's not really a solution. Whats odd, in the preview the retractions are all aligned and don't match up with where I see the artifacts. 

I'm thinking there has got to be something up with the hot end causing this, kinda at a loss and may just have to raise a support ticket.

@Chin

 

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Posted : 18/06/2020 8:46 pm
Oxygen
(@oxygen)
Estimable Member
Posted by: @thomas-b13

[...]

Please send me the STL of your project (either here of by by sending me a direct message) I'll print it and then we see where the issue is

Mini with FW:4.2.1 + Bondtech Heatbreak...
Posted : 18/06/2020 9:17 pm
thomas.b13
(@thomas-b13)
Eminent Member

@oxygen

Printed with the filament I had in, matte black. Looks ok to me, apart from a slight defect on the right in photo. Based on that file and what I saw I'm guessing there is very little retraction going on?

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Posted : 18/06/2020 10:32 pm
Oxygen
(@oxygen)
Estimable Member

agreed, this is after you placed the bondtech heat-break or before?

Mini with FW:4.2.1 + Bondtech Heatbreak...
Posted : 19/06/2020 6:56 am
Stephen
 ste
(@ste)
Active Member

Hello, 

Just out of interest, what temps are you trying to print at and have you printed a temp tower. I was getting this problem and retraction got it down so far but then still had little gaps. I did a temp tower and I was printing the models at to high temp and needed to come down to 180 for my PLA. No more problems since. 

Posted : 19/06/2020 11:37 am
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