Negative Mold

shai_perednik

I need to create a negative mold of this fan duct which will then be used with simscale to simulate airflow and improve the duct.
How can I create a negative of this shape?  Any suggestions on where to start?
doc @ https://cad.onshape.com/documents/14f3d01d62b5237f728896c5/w/40e0afc950b8ca0dfecf9ef8/e/f3ea28b89020464ba125df5d.

Thank you!

bradley_sauln

The best way is to extrude a box as a new part around this fan so that both openings of the duck line up with the box faces. Then use the boolean subtract tool to create your negative: https://cad.onshape.com/help/#booleanparts.htm?Highlight=boolean

*Make sure to check off "keep tools" so that you don't lose your part.

bradley_sauln

The best way is to extrude a box as a new part around this fan so that both openings of the duck line up with the box faces. Then use the boolean subtract tool to create your negative: https://cad.onshape.com/help/#booleanparts.htm?Highlight=boolean

*Make sure to check off "keep tools" so that you don't lose your part.

shai_perednik

I tried that, but maybe my box wasn't setup right, I'll try it again

UPDATE.  that worked.  I had to sketch a box at the bottom and top of the duct, then loft between them to get the right shape.

øyvind_kaurstad

I'm also working on a cooling solution for my 3D printer, and I've also thought about using Simscale, but it seems a bit difficult to get going (because of the sheer complexity). I hadn't really thought about creating a negative to get a representation of just the internal shape, though. Now that I think about it, it seems obvious, so thank you for the tip.  :-)

Please update this thread with your progress on using Simscale for this, if you don't mind.

shai_perednik

Will do. I actually just imported the step file into simscale and started the mesh translation process.  I'll post any updates!

shai_perednik

I'm likely continuing this topic with the SimScale team @ https://www.simscale.com/forum/t/eniac40-layerfan-simulation-project-by-shaiss/47743 incase your interested 

øyvind_kaurstad

@shai_perednik: Thanks, I will follow that thread with interest.