Shell tool gives wrong dimensions?

daniel_gross754

I am trying to make a vacuum nozzle that goes from a ⌀1.2" to a ⌀0.5". I make two sketches, one of them offset above the first by 1 inch, and the bottom circle is ⌀1.2625" and the top circle is ⌀0.5625". I use the loft tool to make a cone-shaped transition between them, and then use the shell tool to make the solid shape a hollow cone with walls of 1/16" or 0.0625". I then measure the distance between the two circles, and I get 0.066218 in which is not 0.0625 in. How is this possible, and what do I do to fix this?
Document link: https://cad.onshape.com/documents/4a9cc4bfadeb446d9d3e17e5/w/59eb5abbce17118dfd9af26f/e/991ccafa440a9706162821ed?renderMode=0&uiState=63dff0dc52901e10760b1192

bryan_lagrange

How about this

https://cad.onshape.com/documents/45caccaf3ef607f4df1ebb92/w/929edbb093ad38bbeedb76fb/e/d014d5e3bdb10408ef475f6c

NeilCooke

Because shell is a wall offset.

daniel_gross754

Okay...so how would I make a hollow "cone" with a wall thickness of 1/16"? I can't loft between two rings, it does not allow that.

bryan_lagrange

How about this

https://cad.onshape.com/documents/45caccaf3ef607f4df1ebb92/w/929edbb093ad38bbeedb76fb/e/d014d5e3bdb10408ef475f6c

NeilCooke

Shell to 1/16" - trigonometry states that the distance measured between the two "top rings" is not the same as the wall thickness.

daniel_gross754

I did find the solution and it is what bryan_lagrange linked, but slightly different. As NeilCooke said that the distance between the top rings is not the same as the wall thickness. The answer is: Make a sketch for a revolve action, and set the distance between the two rings, not the distance between the line.