Tapering zig-zag extrusion with fillets

Hi All,

I’m trying to create an extrusion where the cross section scales as it goes along the rail. Using sweep2 gave me something close, but it gets real wonky at the turns due to the radii changing the distance between the rails.

Alternatively, I’ve tried building it without fillets, which gives me the 3d shape I need but I have no clue on how to soften all the edges. The contour of the first set of rails is fixed, so I would probably have to manually edit the edges individually.

Any advice on how to go about modeling this?

sweep2 w/ curved rails:

sweep2 w/ straight rails:

tapered zig.3dm (691.4 KB)

Hello - I guess that is going to be tricky - or tedious at least. I think I’d just work with FilletSrf here and make these all by hand, so to speak. FilletEdge can get you a lot of the surfaces if you guess right on the radii, but it will not trim in right with this configuration, and I think it will be better just using FIlletSrf all the way…

The key will be getting the top corners filleted - you need to make fillets between fillets and surfaces, so the order is important, and there will be trimming to do…

Here’s one corner:tapered zigCorner.3dm (198.7 KB)


thanks for the response pascal.

the big issue was keeping the various radii on the rails. I was playing around with blendsrf but realized I could just loft the whole thing with another crv for the peak. A lot less edges to clean up with fillet this way too.