how to extrude a surface up to another surface

jeff_mcaffer

In spa patio | Part Studio 1 Copy 1 (onshape.com) I have the lower (gold/brown) thicken and the upper (orange) extrude and I'd like to estimate the volume between them. I figured I'd just extrude one up to the other but the Extrude feature does not seem to let me pick the lower (thicken) as a "face" to extrude up. If I use the upper as the face to extrude down, picking the lower gives an error when used as the "upto" part. (see Extrude 12).

I know the two surfaces do not have an exactly matching permitter but hope that's not the issue (don't see how I can make them align 100%). I also noted that you can't extrude any element of the thickened surface so it seems I've done something basic incorrectly with the thicken? Should a thickened part be just like any other part and have faces?

Help?

eric_pesty

Extrude 12 is failing because the "terrain" doesn't cover the entire area so in some places it has nowhere to "stop". Add a "move boundary" before you thicken (or I don't even know if you need the thicken at all?) so that the terrain is larger and it works:

eric_pesty

jeff_mcaffer said:

Oh. We'll there's that. It's there another feature that projects a perimeter and fills the inside? I guess you could put a plane in the middle and extrude both ways upto the surfaces. That would also allow you to define the angle of the edges (by tilting the plane).

Thanks again. Super helpful.

A loft could be an option but in this case the shapes are too different for it to "figure it out" (I had a quick go at it and it was a mess). The only other way I can think off would be to manually create lofted "faces" around the perimeter, and probably use a couple "fill" features to close up some of the resulting openings, then you would be able to use the "enclose" features to create a solid. I haven't tried it but that should work...

eric_pesty

Extrude 12 is failing because the "terrain" doesn't cover the entire area so in some places it has nowhere to "stop". Add a "move boundary" before you thicken (or I don't even know if you need the thicken at all?) so that the terrain is larger and it works:

jeff_mcaffer

Nice. I didn't know about Move Boundary. Makes it easy. Thanks

jeff_mcaffer

Actually, a quick follow question. Why can't I use "terrain" as the thing to extrude? It should have a face (I was thickening as an experiment do see if that would give something extrudable). 

eric_pesty

jeff_mcaffer said:

Actually, a quick follow question. Why can't I use "terrain" as the thing to extrude? It should have a face (I was thickening as an experiment do see if that would give something extrudable). 

Extrude only works on planar faces. 

jeff_mcaffer

Oh. We'll there's that. It's there another feature that projects a perimeter and fills the inside? I guess you could put a plane in the middle and extrude both ways upto the surfaces. That would also allow you to define the angle of the edges (by tilting the plane).

Thanks again. Super helpful.

eric_pesty

jeff_mcaffer said:

Oh. We'll there's that. It's there another feature that projects a perimeter and fills the inside? I guess you could put a plane in the middle and extrude both ways upto the surfaces. That would also allow you to define the angle of the edges (by tilting the plane).

Thanks again. Super helpful.

A loft could be an option but in this case the shapes are too different for it to "figure it out" (I had a quick go at it and it was a mess). The only other way I can think off would be to manually create lofted "faces" around the perimeter, and probably use a couple "fill" features to close up some of the resulting openings, then you would be able to use the "enclose" features to create a solid. I haven't tried it but that should work...