Hi there, not sure if this is the right place to post this but ill give it a go. This is my first post and im really new to 3d printing.
I am having some problems with a model I am trying to print. I have created it in blender, then exported it as an stl but I am getting holes at the top of the model. its quite a thin wall. I was wondering if anyone could give me some ideas on how to fix it. Its quite a thin model, only 1mm but even when I increase the thickness to 2mm I am still getting problems. I have attached the Blender file and the stl.
Layer thickness? I recommend 0.2mm unless a smoother surface is desired, then try 0.1mm.
Number of perimeters? I recommend at least 2.
Number of top and bottom solid layers? I try to keep the shell uniform, so I would go with 4 top and bottom solid layers if using a 0.4mm nozzle and 0.2mm layer height.
Infill? There really isn’t any even at only 2 perimeters and 4 top/bottom layers, so whatever you want.
Orientation? Is it laying flat on the print bed like this?
Looks like the headlight trim ring for an older VW Bug.
EDIT: What slicer are you using? I ask, because when I opened it in PrusaSlicer, it warned me that the object was dimensioned in m, and asked if I wanted to scale it to mm, and I said yes, and it brought it in with a volumetric dimension of:
Hi there, thanks for replying, ha ha you are close. Its a headlight surround for a 1967 vespa small frame that I have renovated. I broke the chrome one and needed a black one anyway. So thought I would print one and then spray it.
I have played around with different setting but none seemed to fix it so at the moment I am back to the default. Which pretty much looks the same as when I made loads of change. Its just the top thats being a pain.
And yep, its laying flat on the bed. Im using the slicer within Bambu Lab studio. The size is correct. It also asks me to change it to MM. the blender file is actually also in MM but it still asks me for some reason. But the measurement you have there of around 128mm is correct.
Ill gave your suggested parameters a whirl but getting similar results. See image.
It might have something to do with my original blender file? even though I now hove it set at 2mm thickness.
Okay, you are getting holes in the actual printed part?
Because from the screenshot you just posted, it sliced just fine. I am not seeing any holes in the sliced object, just the layers that make it look stepped because of the shallow curvature.
Yeah it seems to slice fine however the top part of the object still has a load of holes in it. After diving a little deeper into my actual model I seemed to have a load of zero faces and Non manifold edges. Im going to try to make the model again.
Here are a few images, the sides are looking wonderful, its just this top curved section. Couple of better results. the best one however is too wide on the top edge.
Nozzle is 0.4mm, standard basic Bambu Lab Basic.
I have actually rotated the whole object 90°. Basically so it prints vertical its sorted the top curve out but now the inside walls as a little crap. But im only printing a quick test. Just adds a bit more time printing it this way though due to all the supports I need.
Test 2 and test 3 look like you have 0% infill. I would set your infill to 100% if you can. When I slice the model you uploaded, there is 1.8mm of printed material - 9 layers of 0.2mm thick layers. That should be plenty for a good surface.
Actually, what it looks like is under-extrusion. The bridging layer did not join the perimeter layer properly. Test 1 looks the best, but even it looks like it has under-extrusion.
You should put a 6mm brim on both the inside and outside perimeter to help hold it to the print surface. It could be pulling up a bit as well. Enough to affect the print, but not enough to notice.
For a round object like this, I will almost always set enough perimeters that it’s all perimeters, and not use any infill generation. Tends to create a more consistent part and it’s a lot faster to print than having the bed/nozzle vibrate away creating infill, and I think it’s stronger too.
And in addition to setting it to like 8 perimeters as @mcdanlj recommended, definitely use an inner and outer brim. The wide area at the top hides the crazy thin wall that is the only attachment to the build plate.
BINGO, you can’t trust any of what’s going on after your model has separated from the build surface. It looks like all 3 of the pieces in the photos had come loose from the build surface.
Brim or even raft if you have to.
Hi guys, thanks for all the help. Ive changed a few setting as recommended by your good selves. the model certainly looks better but im still getting some holes on top.
Here are the setting I have changed. Everything else is default:
Layer Height: 0.1mm
Wall loops (perimeters): 8. I tried more but it doesnt effect it.
Detect thin wall: On
Top/Bottom layer shells: 4
Sparse infill density: 0
Raft layers: 2
Brim type: Inner and Outer
Brim width: 6mm
Brim-Object gap: 1mm
Is there anything I am missing Thanks for your patience guys. Bit of a new boy here.
I just increased the line width of the inner and outer wall and it seemed to have closed up the holes a little. But I am not sure thats the best way to do it?
Well guys, it looks like we have some great success. I printed off just the top part and it has come out great. No holes. I have given the piece a little sanding so smooth out the rough bits but looks great.
The supports are a real pain to get out as they are so small and trapped between the walls, but thats a minor thing.
Thanks so much for all your help. I know where to come next time.
I do not understand this statement. There should not have been any supports “trapped between the walls”, unless you meant just this shallow cove on the underside of the rim?
