Help with Surfaces

[mcyr]

Hi All,

I am fairly new to ACAD2000 and would like to make a 3D surface defined by three orthogonal arcs, with each end tied to the end of another. In the end it would "look" like half a shoe stretcher, if that makes sense. I've attached a file if that helps.

Does anyone know what command to do this? Also, would the command work if one or more of the arcs was replaced with a polyline? Thanks for any help!!

Best regards,
Mike

[ger21]

AutoCAD won't do it with 3 arcs. If you can clip the point a very small amount with another line (or arc or spine) you can use the tabsurf command. Use surftab1 and surftab2 to specify the resolution of the mesh.

[mcyr]

Thanks, Gerry. I was glad to see you respond because you've always provided the best information. I thought about the solution you suggested but I got lazy and thought I'd check to see if there might be a better way. Are you familiar with other CAD software that might do what I'm looking for? Thanks again.

Best regards,
Mike

[ger21]

Rhino probably would, but I don't know for sure. What I'd do is draw a small arc a very small distance from the point, and use tabsurf to create the surface. Then go back and fill in the point with individual 3D faces. The reason AutoCAD won't do it is because meshes in AutoCAD can't contain triangular faces, which you'd end up with at the point. That's why I'd draw the 3D faces in. If you want to post your drawing, I'll do it for you.

[mcyr]

Thanks again, Gerry. I broke the top ellipse/arc and extended it with a line (where the ellipse was pretty flat), creating 4 entities. I've attached what I was after below.

I'm trying to figure out how to mill foam wings with my DIY CNC that can't be cut with a hot wire foam cutter (non-symmethric ellipitical planforms) and needed to figure out a way to keep the wing tips from reducing down to a line/single point at the tips. With 4 entities available I was able to use the edgesurf command to create the surfaces I was after. I'm going to give your solution a try because I'm sure I'll learn something new that will come in handly in the future.

Best regards,

Mike