issue with sweep

AmRad

I am creating 3/4" NPT threads on this part, and i have successfully got the sweep to work on the adjacent side from this but doing the exact same steps wont allow this sweep to generate. How would I go about finding what is causing it to not generate?

AmRad

It works fine if I select new instead of add or remove.

 

_anton

Looking at the red curves, I'm guessing you're creating nonmanifold geometry. Have you tried the Thread Creator feature? That might be more robust than a manual sweep.

MichaelPascoe

You can hover over the red feature and it will give you an error hint. The issue is probably that when it tries to remove the material, it is creating a shared vertex or edge. 

Onshape has decided not to handle non-manifold edges, probably due to the Parasolid kernel that Onshape is built on. An example of non-manifold edges is when two squares are diagonal from each other and they share the same corner edge. This could be what is happening with your sweep. You can try to use the boolean feature separately. Even try thickening the entire part a very small amount so that it doesn't share any edges with the part you are merging it with.

Please share a link and make your document public if you would like more specific help with it.

rick_randall

I believe the issue is 1) where the triangular profile touches the edge of the original part - or 2) the pitch is the same as the length of the side of the triangle profile

1) try separating the triangle (create a gap) from whatever geometry you used to position it to the original part by a very tiny fraction. - or

2) reduce the side of triangle profile by a tiny fraction (say, half a thousandth smaller than the pitch)

 Hope this helps

martin_kopplow

If I had it working on the adjacent side, I'd just cut the thing in half and use a circular pattern of 180°/2 instances/add. I'd probably do that anyway. ;0)