Weird Z seam phenomenon
Trying to print the PlanePrint thinwall wing test part in anticipation of building their Notos. https://www.planeprint.com/notos
Printer - Prusa Mk3S, Diamondback 0.4mm nozzle, 0.25mm layer height, with Polymaker LW-PLA (pre-foamed).
I have no problem printing this material normally, but have run into an odd issue. This part (and most of the plane) is designed as a surface, so it can only be sliced using experimental Surface mode in Cura 4.12.1. I have moved over completely to PrusaSlicer more than 1 year ago, but the single wall surface model design cannot be sliced in PrusaSlicer. Vase mode does not work for this part, either.
I was struggling to eliminate holes in the underside of the angled triangular flat wall. It appeared to be under-extruding, I believe. Despite the appearance of the part, prior to cleaning it up, I am having zero issues with stringing on this part or other parts. Internal parts are clean.
Per Rene at PlanePrint, I've increased the retraction prime amount to as high as 1.5 to get the angled wall to fill completely. At the Z seam I can watch the print head actually print this weird wall perpendicular to the Z seam, despite it not being visible in the slicing preview movements. As I increased retraction prime amount from 0 to 0.3 to 0.5 to 1.0 to 1.5 I've seen this weird wall extend further and further out from the actual wing part. The weird wall is actually a full wall thickness thick.
In the cleaned-up part, you can see the underside of the triangular wall. The slot in the back vertical wall is for a hinge to be inserted. It's not a defect.
I have not seen similar defects in image searches I've done.
- Any idea what causes it and what to do about it?
- And as an adjunct, is there any chance that PrusaSlicer will ever support this sort of surface model? The Bambu guys are asking the same question on their forum, as their slicers is based on PrusaSlicer.
The part I'm printing is in the tuning parts file here https://www.planeprint.com/free-tuning-parts. The part is called WINGTEST_P3 LW_Planeprint.stl if anyone wants to try it. It's a 35 minute print and weighs 3 grams.
Thanks in advance for any and all suggestions!
RE: Weird Z seam phenomenon
Can you please attach the file as a Project file?
Click, 'File.Save Project As'... in Prusa slicer, and save the project as a .3mf file, then zip compress the project file and attach the zipfile to your next post.
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
RE: Weird Z seam phenomenon
Thank you, Joan,
I wish I could upload a PrusaSlicer file. The part in the photos had to be sliced in Cura, not PrusaSlicer, because this part can't actually be sliced in Prusaslicer. I know it sounds weird, but it's true. PrusaSlicer doesn't support the surface mode for this particular single wall surface model. I've seen that problem posted elsewhere.
The link to the test part STL and partfile name are in the original post if you or anyone else wants to give it a shot.
I've talked with PlanePrint.com and while they have PrusaSlicer settings (and Cura settings) for many of their aircraft, they cannot do so for this particular model and certain others. A special experimental surface setting in Cura 4.12.1 is required. Trust me, I do not wish to use Cura any longer. It gives me a headache.
Here's a guy who uses these same PrintPlane.com test tuning parts to dial in his printers for another plane.
I can't help you with your current issue but these pages might be of use:
https://blog.prusa3d.com/3dlabprint_3d-printed_airplanes_74900/
https://3dlabprint.com/faq/prusaslicer/
Cheerio,
RE: Weird Z seam phenomenon
That 2nd link, with even/odd settings looks like something I'll try tonight. Thank you.
RE: Weird Z seam phenomenon
Whelp, as it turns out, the even/odd setting mentioned here https://3dlabprint.com/faq/prusaslicer/ was something I'd already been using in my PrusaSlicer profile for airplanes using LW-PLA. It was already set to that and won't slice properly.
I'd love any other suggestions!
RE: Weird Z seam phenomenon
I spoke too soon. I went back and added ALL of the settings on the page that Diem linked (thank you!). The part appeared to slice fine, with hollow interior and curved interior ribs. But I got an error message "There is an object with no extrusions in the first layer". Sure enough, the sliced part is somehow levitating 1.5mm above the build plate. And I cannot save the gcode or send it directly to the printer. Something in these settings is causing the 1st layers to either not be detected or to levitate. So close...just not yet there.
Settings:
https://3dlabprint.com/faq/prusaslicer/
Help?
You probably have a faulty file, in some circumstances with some CAD software, a microscopically thin extension, far too thin to print, extends beyond the base; the slicer 'balances' the part on it's lowest point but cannot generate extrusions thin enough so nothing is there to hold it up ... hence the warning.
Two possible fixes: split to objects, if the extra is seperate this may be enough 'though the extra *might* still be able to interfere with the print.
Use the cut function to remove the invisible bottom part - logical but not intuitive.
And there are software file fixes that might be better if these don't work.
Cheerio,
RE:
Diem, thanks much for your suggestions. I did the "split to objects" and the slice looks ok, but I got an error "Conflicts in G-code path". I'm setting the print to start and heading in to work. I'll check at lunch.
I've also saved the project (with the levitating part) as a 3mf and it's uploaded here. WINGTEST_P3 LW_Planeprint
You now have two objects occupying the same space - 'split to objects' then 'arrange' and they will be spaced - it slices OK then but I haven't tried to print it.
Cheerio,
RE: Weird Z seam phenomenon
Don't split to Objects, use Split to Parts instead. Looks like it slices ok with that option.
If you trim the bottom the model will be too short.
Took that model into Blender and the entire bottom is about 430+ intersecting parts so Im not surprised that its missing stuff at that level. I don't think there is any uber thin spike out the bottom as there are no vertices below the model that will cause that. I think its just the bottom of the model itself once you see how its constructed is a mess.
RE:
I didn't "arrange" so it came out less than awesome. Lots of issues. I guess "arrange" will be next?
I will also try "Split to parts", Neophyl. I've made a change in Cura from their forum and it's now printing fine without the weird wall at the Z seam. "Wipe nozzle between layers" was enabled so I disabled and the print is going well. I hope to get it to print well in PrusaSlicer, since I really don't enjoy Cura. At. All.
Thanks @neophyl I hadn't tried parts. I really must take another look at Blender, it seems very useful for this sort of visualisation.
The main body is effectively three seperate compartments held together by a single perimeter on what will become the underside, this is going to be a fragile object. We see quite a few of these plane model issues; I'm never sure if the designers are genuinely pushing the design limits or forcing shapes into 3D printing that would be better made by another technology.
BTW @rcaddiction, white and pastel filaments are always trickier to print because of the high proportion of pigment, you might do better with a dark filament or a clear one.
Cheerio,
RE:
Split to parts gave me essentially the same results as the photos above. I don't understand why the flat bottom of the wing profile is so ratty.
Color - most of us print planes in light colored filaments because the emissivity of dark filaments cause the plastic to heat up and deform in direct sunlight. Plenty of people have printed and flown this F3A style plane. I've finally got the part 100% perfect in Cura, so it's quite possible. I'd just rather not use Cura.
I did find what was weird about the 1.5mm levitated area. It corresponds to an initial layers with extra perimeters on the open surface that sits on the build plate. I can see it on the finished Cura part. The wall is double thick for approx 1.5mm on the one end.
Below is the part printed in Cura 4.12.1 using Surface Mode with zero post cleanup. Wish I could get this done in PrusaSlicer.
