I’m trying to print this PC case part. I was able to print another part where these vents were oriented vertically and they came out perfectly. Last night I had an issue with this part so I dried the filament overnight to eliminate that as an issue. Now I’m still having an issue, but it’s strange because there are 5 rows of vents. The outside rows on either side are printing really nicely and the middle ones are all messed up. And you can see when it’s printing it’s not putting down a clean line, it’s like a thin strip that is raised. Any idea why this is happening/what I can do?
It looks like you may be pushing the limits for overhangs. Depending on what filament (type, brand) you may need to make changes.
You can try the following:
- calibrate your filament for pressure advance and flow ratio
- set wall order to outer first
- slow down outer wall speed by 50%
- slow down your overhang speed
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Hey thanks for the suggestions. I have some questions. Isn’t outer wall first worse for overhangs? I’m happy to try it, but I thought that you want the inner walls printed first to give more surface area for which the inner wall to adhere.
I have already calibrated PA and flow rate (I do this with every filament) so those shouldn’t be the issue.
Lastly, any idea why it’s consistently just those three inner columns or what I can look at to figure that out? I’ve printed this twice now and in both cases the results were identical, good outer columns, terrible inner columns. Obviously happy to try slowing down outer walls, etc, etc, but it doesn’t make sense to me the inconsistency between identical features using all the same settings.
Nozzle size ? Settings ? Can you share the 3mf or export the gcode sliced file ( gcode.3mf ) And is this the same issue you had “last night” ?
It should be inner/outer for overhangs. Doing the outer wall first causes an issue because it doesn’t have anything to support it.
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I’m using a .4mm hardened steel standard flow nozzle. Most of the settings are just the 0.20mm Standard @BBL H2D. The changes (I just used the designer’s settings) are as follows:
Wall generator: Arachne
Wall loops: 4
Support Type: normal(manual)
Support Style: Snug
The filament profile is the Polylite ABS preset, with pressure advanced calibrated (using Ellis’ pattern) and flow rate calibrated as well.
Gcode file is attached below.
Yes, this is the exact same issue I had on the first attempt. The outer column on either side printed pretty well (not perfectly) and the three inner columns have all the defects shown in the photo. The only thing I changed between the two attempts was drying the filament in the AMS2 Pro overnight. I don’t think it was wet, but wanted to eliminate that as a possible issue.
Yeah, the outer wall first was a mistake, my bad. Inner wall first for this design. Have you tried lower layer heights? Any noticeable bed adhesion issues?
It could also be a cooling issue since the center of the part has the issue.
Orcaslicer doesnt load that “.3mf.gcode” but im not sure if thats a problem or not. Bambus new formats are straying really far from open support lol
You mentioned the filament profile was Polylite ABS, and this is assuming that you are actually using Polymaker Polylite ABS as well:
Check your SEAMS. That overhang looks at or over 45degrees, which means it needs all the help it can get. You want your seams to happen on the side of the hole that is not overhung, and each of these “holes” gets its own seam position, so that might differ from the outer row vs the inner rows.
If you have control of this model and the following is acceptable to the airflow - I would reconfigure the angle at 30 degrees, and it’ll magically become way more printable.
This shape combined with ABS’ trademark shrinkage probably is doing some sort of “squeezing” on those outer rows that is not happening on the interior ones.
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I would also slow down 50% and take 5° off the bed leave chamber hot, those overhangs dont look TOO bad they are doable but slow. On the upper surface they are lifting this is also dangerous for the nozzle crashing into them. This happens most of the time because everything is too hot when the nozzle passes for the next layer so it pulls the overhangs up, therefore my recomendation just a tad cooler bed so the part vs. air delta is higher this with slower printing say layertime atleast 300 not 260-280 should result in way better overhangs.
The upper surface looks overextruded too, 0.9975 flow is on the higher side imho but you calibrated that you know it better than me. Since this is a preconfigured file as you stated, it doesnt look like the speeds where altered wich lets me to believe maybe the designer also printed it slower ? 0.16 layerheight as suggested would also help a lot
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Thanks for the tips everyone! Sorry was busy with family and didn’t have any time this weekend but will try to reprint with these suggestions and see how it goes. I’ve been having some adhesion issues at the edges of prints lately so was running the bed at the upper end of the range, but that didn’t seem to help anyway and I needed adhesive. I think the build plate may need to be replaced as well for that problem and hoping these suggestions can clean up those overhangs.
This looks like a slicing error. Send your 3mf file. Sometimes the slicer is not generating brdiges properly so it might need manual tuning.
Youre in the H2 Subforum, there is no orcaslicer here 
sadly
He attached the 3mf.gcode file, those are overhangs, not bridges and they are sliced correctly in the file if hes using this specific file there are not problems in the slicing then. The file like this i would print too, run into the same problems and then try what everyone suggested here already. Should work then
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Yea definitely not a slicing error. FWIW I have a lot of experience with 3D printing (I did my first 3D print in 2003, ran some printing at my last company, and have been printing at home for the last 6 years or so) and I always check my slices for obvious errors before printing. I have less experience with ABS specifically. Some from printing/building a custom 2.4/Doomcube, but have never used Polymaker ABS and this geometry was a bit unique to what I’ve printed before.
Since I made multiple changes, it’s hard to say which was most impactful, but I moved the seams, so they are not on the overhangs and reduced speed. I’ve had some adhesion issues with the build plate I’m using, so rather than lower bed temp I bumped up chamber temps by 5 degrees to get that larger delta.
All the changes combined for an absolutely perfect print. all the overhangs came out pristine.
Thanks for the help everyone, really appreciate it!
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