lofting two pipes together

jeff_mcaffer

I've used the pipe custom feature to create two different diameter pipes and am trying to connect them using a loft. While I can use edges to do a surface loft, I can't use the end faces of the pipe to do a solid loft. I get an error saying you can't use faces/regions with inner loops. Is there a way around this? Most of the related scenarios use some variation of lofting some blocks and then hollowing them out. Unfortunately, in my scenario, the awesome pipe tool is creating hollow pipes so I don't have a block to hollow.

Here's the doc. See the two lofts on the 90 deg elbow.  hydronics | Part Studio 1 (onshape.com)

Ultimately, I want to union all of these into one part and union can't mix solids and surfaces.

eric_pesty

If the pipes are different wall thickness, then you will have to create a sketch on each pipe and loft a solid section, followed by a second loft to remove the center.
You might also be able to create two surface lofts (one for in inside, one fore the outside) and use an "enclose" feature to crate a solid (using these two surfaces and the end faces of the pipes.

That said looking at your model I am not sure you need to do a loft when you could just extend the faces and blend them using chamfers/fillets.

mahir

There's usually lots of different ways to accomplish something in CAD. Here are 4 methods off the top of my head. The regen times don't seem to make much sense, but the simplest method for round pipes is to just revolve the connections.

https://cad.onshape.com/documents/293ea40d717393ea3b840ac5/w/e09235d8b53f6c85272755aa/e/d5851f8f6548362d130e0587

eric_pesty

If the pipes are different wall thickness, then you will have to create a sketch on each pipe and loft a solid section, followed by a second loft to remove the center.
You might also be able to create two surface lofts (one for in inside, one fore the outside) and use an "enclose" feature to crate a solid (using these two surfaces and the end faces of the pipes.

That said looking at your model I am not sure you need to do a loft when you could just extend the faces and blend them using chamfers/fillets.

mahir

There's usually lots of different ways to accomplish something in CAD. Here are 4 methods off the top of my head. The regen times don't seem to make much sense, but the simplest method for round pipes is to just revolve the connections.

https://cad.onshape.com/documents/293ea40d717393ea3b840ac5/w/e09235d8b53f6c85272755aa/e/d5851f8f6548362d130e0587

jeff_mcaffer

Thanks @mahir and @eric_pesty. As I'm learning, lots of different ways of thinking of this. I had tried the inner and outer lofts but didn't click on `enclose`. Similarly, the power of `shell` did not really trigger for me. Great stuff. thanks again.