Push/Extrude to connect rectangular and round shape

Dear experts,

I am designing an air duct adapter between rectangular bower fan nozzle and a round pipe. How do I connect the 2 shapes? I tried to cover individual sections from inside and outside using the Sandbox tool, however this does not get correctly interpreted after the export into .stl…
I am expecting something like intelligent Pull/Extrude along the lines which connect the edges.

Thanks beforehand,


You can do it manually but Curviloft is your friend here.

Great Tool! Many thanks for your help!!!

Just like you see in the store, drawn plan view then pull up. Attached is 1/2 to no particular dimensions.
Check out the engineering tool box they have some ANSI compliant items

I think tis can be developed so if you have break you can buld on site:slight_smile: