Issue with Shell when thickness is bigger than 0,03 inch

alain_ciotta

This is my public design:
https://cad.onshape.com/documents/58ea84ac604d230f769d4631/w/f4d42a9b3a07d5488a1a7e7e/e/761640a13e4f517e5410db22

Look for the tab: Torso v3

When you look to Torso v3, the part looks perfect. The issue I am facing is that every time I increase the thickness of the Shell above 0.03 inch, the part becomes a block and not halo anymore.

The ideal thickness will be 0.2 inch. How can I do that

PS: This part is needed for the STEM project for the VexIQ Worldcome

leon_poot

The small holes in Sketch 3 are causing your issue. The offset from these created by the shell are exactly touching each other in one line at a 0.2 in thickness because of their diameter and distance from each other. Onshape just doesn't know what to do with the faces. Same thing happens when I try to extrude these separately and boolean them to the body after the Shell.

owen_sparks

Here's a bodge to give a thicker shell:-

https://cad.onshape.com/documents/58f5e0e66ac18f1078f5c8be/w/7f6385ea32bd3ee2ca093016/e/48fcf6ddc162fb1dfda9d09c

The principle was to:-
(1) Make a boolen tool that is the negative of the part including the small details that cause the shell to fail.
(2) Delete the faces causing the problems.
(3) Shell to whatever thickness you wish
(4) Use the boolean tool from 1 to put the features back in.

Told you it was a bodge 

I presume you'd need to bash some of the faces to make holes deeper.  I'm sure with some reordering of features there's a much nicer way of doing it!

Cheers, Owen S