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Having a hard time subtracting volume in a mold
victor_elmander
Member Posts: 5 ✭
Hello, pretty new to the surfacing side of onshape. After a lot of struggle, and a lot of circulat patterns of surfaces, I created a specific ornament design I've been thinking about for a while, but I can't seem to get the bolean to subtract the negative space in the mold (to be...). Am i doing anything wrong? Any other way around it?
Best Answer
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jelte_steur814
Member Posts: 183 PRO
here's an example of how you could approach it:
https://cad.onshape.com/documents/65f7c6c9f2b966ffd379b657/w/87dcdd466097de5cb104cbad/e/a81b6daafedb7fcf75b6bb97
I couldn't help myself and try this approach
0
Answers
This Boolean add of the 2 parts. See mass properties in lower right corner.
https://cad.onshape.com/documents/e4f73206564fcbec2c5f5ae4/w/302c910b85f39225c5c3a6c8/e/b9e7f994f861cf2201480586
@victor_elmander
Even though you have a composite part, it is made up of nothing but a bunch of surfaces. I don't think Onshape will let you use surfaces in a boolean. Also, if you can convert this to a proper part as is, I expect you will see the classic non-manifold geometry error come up.
I'd figure out the smallest section of the ornament that you can find that doesn't repeat itself. try and design that and create it into a solid slice.
(perhaps you can even do that by deriving some of these surfaces into a new part studio and trimming it smartly.)
then create one circular slice for the mold
then create a circular part pattern and mirror for both the mould and the part.
that'll save a whole lot of work and compute….
Thank you for the ideas, haven't got the time to test it further, as far as I understand it on your answers theres no easy way out. I might try to create it as a solid model from scratch, probably gonna need a lot of workarounds. Would be easy if the walls in a solid "followed" other surfaces when the transform command is used.
Might also try other CAD-softwares or 3D-modeling softwares. Thanks for the answers!
While you can use composite parts to subtract volume... They have to be a solid body. I've subtracted clean watertight STL files from native geometry successfully. The part in you example and the screenshot below will need some TLC to be able to use it in this case as onshape doesn't see it as a watertight object..
@victor_elmander :
here's an example of how you could approach it:
https://cad.onshape.com/documents/65f7c6c9f2b966ffd379b657/w/87dcdd466097de5cb104cbad/e/a81b6daafedb7fcf75b6bb97
I couldn't help myself and try this approach
@jelte_steur814 Thank you for the solution, will go through it and try it by myselft!