Sweep around circle projected onto the side of a cylinder

Wolfram

I'm trying to create what amounts to a saddle shaped square groove around a hole in the side of a cylinder.  

Quick recap:
I created a sketch on an offset plane defining the inside wall of the groove and did a surface extrusion down to the cylinder wall to create the "wrapped" feature.  
On a perpendicular plane, I created the groove sketch, constrained it with Pierce to the projected path of the intersection of the surface extrusion and cylinder.  
Sweeping that sketch along the projected path created what initially looked like the groove I was going for.  

After a closer look, the sweep does not maintain the original depth of the groove.  Is there a way to achieve a constant depth groove around a wrapped path?  

FWIW, I imported the initial geometry from an .iges generated from my CMM inspection.  I disabled the import after extracting the shapes/sizes I needed, but don't know if this is creating any problems.

https://cad.onshape.com/documents/58a4dc84baa7e90f794dc5c8/w/a7a3f7edbe30043501d3ff8d/e/52139405c6ba1d810a77e170

Thanks in advance!
-Tim

NeilCooke

Hi @Wolfram should the side walls of the groove be vertical wrt the axis of the bore or angle around the bore like in your model? If they should be vertical you can extrude a sketch up to face with offset (new last week).

philip_thomas

@Wolfram - Thank you for your post. Posting a link to your problem is ABSOLUTELY the best way to get help.
I have no idea if i have correctly understood your needs, but wanted to offer a couple of geometry solutions that might help you.
The document pasted below contains two additional part studios that shows a couple of different end-cases. 
In the 'vertical' solution, the groove walls remain vertical and parallel to one another.
In the 'normal' solution, the groove walls remain perpendicular to the base part and parallel to one another.

Again i have no idea if this is what you wanted and i am happy to answer any questions.

https://cad.onshape.com/documents/58a6181b22115e0f6fe02a1d/w/2ff0f97f44b2066711040dfa/e/cb1c4fe9a5665785f43b4344

philip_thomas

Dammit - @NeilCooke posted while i was building mine!

NeilCooke

Hi @Wolfram should the side walls of the groove be vertical wrt the axis of the bore or angle around the bore like in your model? If they should be vertical you can extrude a sketch up to face with offset (new last week).

philip_thomas

@Wolfram - Thank you for your post. Posting a link to your problem is ABSOLUTELY the best way to get help.
I have no idea if i have correctly understood your needs, but wanted to offer a couple of geometry solutions that might help you.
The document pasted below contains two additional part studios that shows a couple of different end-cases. 
In the 'vertical' solution, the groove walls remain vertical and parallel to one another.
In the 'normal' solution, the groove walls remain perpendicular to the base part and parallel to one another.

Again i have no idea if this is what you wanted and i am happy to answer any questions.

https://cad.onshape.com/documents/58a6181b22115e0f6fe02a1d/w/2ff0f97f44b2066711040dfa/e/cb1c4fe9a5665785f43b4344

philip_thomas

Dammit - @NeilCooke posted while i was building mine!

Wolfram

Thanks for the responses guys!  To answer @Neilcooke's   question late, yes, the groove walls need to stay normal to the base part.  @Philip_thomas , your "normal" solution works great.  

For my understanding, what caused the behavior of the sweep I had tried?  The groove wall was somewhere between normal to the surface and inline with the projection.  

Thanks again for your help.