(SOLVED) ABS print issue: Blobs/Zits on final print (pics)

Help with printing with specific plastic filaments.
gapdev
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by gapdev » Sun Sep 25, 2016 12:46 pm

Set the extrusion width to 0.50 and you should be good to go.

Kenny

mpick67
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by mpick67 » Sun Sep 25, 2016 4:34 pm

gapdev wrote:Set the extrusion width to 0.50 and you should be good to go.

Kenny
Hello Kenny,

Just made the adjustments. I'm printing the part right now, and I think it's going to work! THANK YOU! :D

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DougZ
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by DougZ » Sun Sep 25, 2016 6:00 pm

Ah @gapdev, you saw where I was headed, but actually, I'm not sure that is exactly the solution. The raw model gcode preview shows the thin wall gap issue, as shown here:
pic1.png


Note: for some reason the 2nd and 3rd pics seem to be displaying out of order after posting my message. They looked OK when I did the preview however after submitting the post the two pics seemed to swap places. The filenames are correct but the images are swapped.


Changing the extrusion width from Auto to Fixed @ 0.50mm looks better, but I notice the preview still shows some gap (look near the corner):
pic2.png
pic2.png (102.26 KiB) Viewed 2280 times
Is I change the extrusion width back to Auto and instead go to the Infill tab and change the Outline Overlap to 50%, look what happens:
pic3.png
@mpick67, if the extrusion width setting doesn't completely solve your issue, try this additional setting. Also, no need to print the entire model, you can print just a portion of it and/or use multiple processes to test different settings in the same print job on the same model. Let me know if you need more info on how to do that.
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mpick67
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by mpick67 » Sun Sep 25, 2016 7:36 pm

gapdev wrote:Set the extrusion width to 0.50 and you should be good to go.

Kenny

Ok, I thought that was going to work, but near the end of the print it started messing up again. :|
DSCF7130-2000.jpg
DSCF7129-2000.jpg
I'm going to try your solution next @DougZ.

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DougZ
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by DougZ » Sun Sep 25, 2016 8:08 pm

Sounds good. If thy doesn't work I will try printing it myself using the same filament to see what happens. If I have success I'll post the .fff file so you can compare settings.

I may also try Cura. The electrical box in my initial post was sliced using Cura and turned out great.

Are you hiring any popping/snapping when printing?
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mpick67
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by mpick67 » Sun Sep 25, 2016 9:36 pm

DougZ wrote:Sounds good. If thy doesn't work I will try printing it myself using the same filament to see what happens. If I have success I'll post the .fff file so you can compare settings.

I may also try Cura. The electrical box in my initial post was sliced using Cura and turned out great.

Are you hiring any popping/snapping when printing?
No, I don't hear any popping or snapping sounds.

I printed the stl again in CURA for a baseline with a Filament Diamter of 2.95. While this improved the CURA "version" of the print slightly, I still see significant blobs/zits like before.
DSCF7131-2000.jpg
I then printed the file again with Extrusion: AUTO and Outline Overlap: 40% (I chose this over 50% because this was the lowest outline overlap that infilled 100% of my model according to the gcode viewer.
DSCF7132-2000.jpg
Also, I edited the model slightly to make all of the wall thickness of my model the same. One wall was .005 mm thinner than the rest. Here is the new stl I'm trying to print. Again, thanks for all the support and help guys! I really appreciate it! :D
Attachments
nasa cast v2_fixed.stl
(119.32 KiB) Downloaded 59 times

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piercet
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by piercet » Mon Sep 26, 2016 8:00 am

mpick67 wrote:
I printed the stl again in CURA for a baseline with a Filament Diamter of 2.95. While this improved the CURA "version" of the print slightly, I still see significant blobs/zits like before.
Those are at least mostly layer start points. You probably have Randomize Layer Starting location and Start external perimiters first enabled. That or this is a thin enough part that it can't hide the start blob inside. If you turn off random layer starting location, you should end up with those blobs in a line. You can minimize them by playing with retraction settings, making the model a minimum of 3 passes thick, enabling a "start layers in corners or inner perimiters" button if cura has one, or similar techniques.

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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by gapdev » Mon Sep 26, 2016 12:56 pm

Personally, I would redesign the box so it is a multiple of my extrusion width, so that there is either a good amount of infill, or it only uses perimeters for infill.

Simplify 3D has known issues with thin walls (although if you design around the issues, they no longer become issues :o ). The gap fill quandrum is another issue.

Kenny

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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by kcchen_00 » Mon Sep 26, 2016 2:38 pm

Gapdev is spot on, IMO.

If you can redesign the wall to be a multiple of your extrusion width that would be best. Otherwise adjusting the extrusion width slightly (+/-.05) can fool S3D into getting a better thin wall fill.

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DougZ
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Re: ABS print issue: Blobs/Zits on final print (pics)

Post by DougZ » Mon Sep 26, 2016 5:48 pm

I experienced the same printing your model. What did you design it in and what wall thickness were you going for? I measured 1.61mm ~ 1.63mm. Echoing what others have said, try making your walls a multiple of your nozzle size (if fixed) or extrusion width (if auto)..
Last edited by DougZ on Mon Sep 26, 2016 10:46 pm, edited 1 time in total.
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