What am I doing wrong when I try to remove-extrude a tangent circle partway through a larger object?

bruce_lortz

https://cad.onshape.com/documents/58606695cf3a52102fa47e41/w/0db91893da8c5462d41ada9c/e/6b3a099e251b66fedbe8707e

I could have sworn this worked in the past. However, I can not see what I'm doing wrong at this time. I would like to make two circles extruded through a larger object. The innermost circle goes completely through the object, the second circle, tangent to the inside circumference of the innermost circle only penetrates through half of the object.

I noticed that if I avoid using the upper right hand section of the second circle, the object will render, and I can possibly do some other sort of manipulation to get what I want. But I'm curious as to why this is failing.

Thank you for your time,
Bruce Lortz

mahir

It's probably because you're trying to generate a cut with a degenerate edge. CAD doesn't like knife edges (zero thickness geometry). Instead, for the half-depth extrude a full circle. The end result will be what you want. See the link below.

https://cad.onshape.com/documents/58607487ef12fe1027f18a8f/w/27d918441d095c401eb50aac/e/a585510b81662e3a62d19042

mahir

It's probably because you're trying to generate a cut with a degenerate edge. CAD doesn't like knife edges (zero thickness geometry). Instead, for the half-depth extrude a full circle. The end result will be what you want. See the link below.

https://cad.onshape.com/documents/58607487ef12fe1027f18a8f/w/27d918441d095c401eb50aac/e/a585510b81662e3a62d19042

bruce_lortz

Thanks for the info. I still see this as a failure of the software. It is not idiot-proof enough to stop the likes of me.