Hi Brian,

I found that the circle you used to extrude the tube is not planar or flat, see picture.
I'm not sure how you have drawn the circle but if you do need the end at an angle it's best to draw the circle say in the front view first then extrude it, do your shelling then draw a curve at the angle and position you want and Boolean Diff.

Unless the circle was supposed to be flat ? ;)



Hope this is clear.
Cheers

Thank you both.
However, regardless of the source "flatness" or whatever I feel that such finicky things impeding the workflow are a bit of a bummer!

Here is a screen grab showing the source of the extrusion from the earlier boolean.

Brian

Danny was right with the flat circle. I cut it off flat and it shelled fine. Brian your probably like me with trying to figure out why certain things work then dont work. Shelling is a fine operation with a model that needs to be set up properly to work. Dont be discouraged that there are many different ways to do the same thing. I think for me personally I have to put more time into the design decision before I start whaling away.

Try a second approach and you may find your MoI.

Burr

Thanks Burr.
I tried out some variations on a theme which I am sure you can work out from the screen grab.
There are some funny "variables" which need different solutions for an apparent similar working principle.

Maybe others may want to experiment also.

Brian