Trying to make a duct between two rectangles on offset planes

aaron_kahn

I am trying to make a simple little fan duct for my 3d printer but I can't figure out what steps to take. I want to connect the two parts with a smooth even thickness. Sorry if this is a super noob type question. 

Here is what I have done so far:
https://cad.onshape.com/documents/da50eb6eeb8dbcc1bf8a1546/w/788cfb197c90b551e4f03d46/e/602e174d4a265f720d9d1c29

owen_sparks

... and after a few fillets and a boolean:-



O.S.

aaron_kahn

I figured out how to do it by breaking down the duct into 4 sides by drawing diagonal inside corners, then loft the 4 sides separately between the 2 parts and it worked. Seems like it could be smoother and nicer looking so I'm still open to ideas on a better way to go about it.   

owen_sparks

** Deleted duplicate post.

owen_sparks

Hi @aaron_kahn

Here is my take on it, there will be others I'm sure.

The current loft does not like nested profiles that is to say a sketch with one rectangle within another.

So two appoaches:-
(a) If you want constant wall thickness build the whole lump as a solid and then shell it to the thickness you want.
(b) If you want varying wall thickness loft 2 solids.  One for the outer and the other for the void.  Then boolean the void from the outer.

The example below uses (a), all that is left is to boolean the new duct part to your existing bits.  

To make it I've:-
(i) Deleted the nested profiles from your sketch 5 and sketch 6
(ii) Made a loft between those sketches. 
(iii) Used match tangency Edit, no I didn't, it was "normal to sketch" on each sketch to form a nice smooth join
(iv) Used match vertices to avoid a nasty twist
(v) Shelled the part.



https://cad.onshape.com/documents/573714b2d007469f0d6a61fe/w/079616fbf96a95463611abe0/e/14c0685599b6fd8f8d89cb7a

Hope that helps,

Owen S.

owen_sparks

... and after a few fillets and a boolean:-



O.S.

aaron_kahn

That is awesome @owen_sparks !!! That's exactly what I was trying to do! I will study what you did and see if I can implement that. Thanks for your help!!

owen_sparks

aaron_kahn said:

That is awesome @owen_sparks !!! That's exactly what I was trying to do! I will study what you did and see if I can implement that. Thanks for your help!!

You're welcome, happy to help.

Shout if it doesn't make sense.

Cheers,

Owen S.