This is my first post here. I’ve mostly been working in Fusion 360 in the past, but I recently started exploring Rhino and Grasshopper… and I’m really loving the freedom and power they offer. I’m still learning the best practices, so I’m hoping to get some guidance from the community.
I’m trying to prepare a model for 3D printing in vase mode.
My goal is to export only the curved surfaces of a repeating pattern generated in Grasshopper (a kind of wavy, interlocking weave).
The issue happens at the slicing stage:
the surfaces have irregular junctions, small breaks or misalignments between modules. In Rhino the geometry looks clean, but when I inspect section cuts (or once in the slicer), the transitions between surfaces are not smooth. I’ll attach an image so the problem is clearer.
I’ve tried several approaches, including:
– Join Brep
– Mesh Brep with high-resolution settings
– Split / slice
– Baking and using Join directly in Rhino
…but I still get small “seams” or discontinuities that show up during slicing.
What’s interesting is that I previously got this working when exporting a similar surface-based model from Fusion 360: the slicer followed the surface smoothly with no breaks. With Grasshopper, I can’t reproduce that same continuity.
I’m attaching my Rhino and Grasshopper files (and a screenshot of the issue) so you can see exactly what I’m working with.
I’m trying to figure out: how do I obtain a single continuous surface (or continuous set of surfaces), without internal seams, from my Grasshopper pattern, so that the slicer can follow it smoothly in vase mode?
Thanks in advance for any help or insight, I really appreciate it.
Thanks for the example, it helped me simplify the initial wave, but it didn’t fix the slicing issue. Even with your clean version, the slicer still shows small breaks along the surface, so vase mode isn’t smooth.
Maybe this could be related to mesh or surface resolution?
I’m attaching a slicer screenshot.
so its not a rhino problem. but happens in the tesselation or slicing.
the wave looks edgy …
do you do the tesselation in rhino? in gh? can you share that?
it could help, to cut the surfaces at the crossings before tesselating.
(just realised that your wave relies on the parametrisation of the arc. thats why your wave length is not constant)
Thanks for the hint about tessellation, that pushed me to look into it. I tried increasing the mesh resolution directly in Grasshopper (screenshot attached), and I pushed the settings very high, but I’m still getting the same issue in the slicer. The small breaks/seams are still there even with a very dense mesh.
Not sure what to try next.
Were you referring to this kind of tessellation, or did you mean something else?
Hi Pierre - you’ve posed a difficult problem for yourself which I don’t think you are going to be able to solve using your proposed method. Vase mode was developed for printing a smooth, solid surface that has a thickness = the diameter of your printer’s nozzle and that can be printed in a single continuous flow of extruded material. The key word there is “continuous”.
This is not what your design specifies, because there is no straightforward way the slicer can get from the top of one of your wiggly layers to the bottom of the next one. The results you got are the slicer’s attempt to do this, but that’s ever going to produce the results you are trying to achieve.
What i did was modify your GH file to use a different, simpler approach that works with no problem by replacing Vase mode with standard layers that have a specified wall thickness of 0.5 mm - but that turn out to be printed as a single loop of filament.
The only issue is the time SUnion requires to produce the final result. My PC has a fairly slow CPU, so for designs like this I installed the Sasquatch add-on which has a nice multi-programmed version of SUnion that saves a fair amount of time. You probably don’t have that add-on, but here’s a screenshot of how it compares with the standard SUnion:
You can see that there is only one loop per layer, which is what a Vase mode print will produce, so this method does produce the thinness you want. I never print things this thin, but it should be ok for a hanging lamp shade that no one touches.
Here’s my tweaked version of your GH file - let me know if you have any questions.
Thanks a lot for the explanation, it definitely helped me understand the limitations of using vase mode with this kind of geometry, at least when coming from Rhino/Grasshopper. In my tests, the slicer just can’t maintain a clean continuous path with the surface data exported from Rhino, which leads to those unwanted jumps and seams.
did a few more tests on my side. Interestingly, I Imported in rhino a 3MF originally from Fusion where I get the clean result I’m looking for in the slicer. But once I re-export that same model from Rhino as 3MF or STL, the file gets altered and I run into the exact same issue I’ve been getting with the Grasshopper-generated version. So this really confirms that vase mode isn’t a good match for this geometry in Rhino/GH.
The good news is that my GH version slices correctly if I stop trying to use vase mode and instead print with a single perimeter at 0.75 mm. That gives me a clean continuous toolpath. I’ll try an additional print with a random seam tomorrow to check if the layer transitions are acceptable.
So for now I’m going to drop the vase mode approach for this project, but I learned a lot about Grasshopper and geometry handling through this process, so it was definitely worth it.
