Rotate surface on a curve

Rhino Rhino for Windows
1

Just a beginner with Rhino. I am trying to rotate a triangle 180 degrees along a ushaped curve. I would think that either a extrude to a curve would have a rotate option but I couldn’t find one. What do you suggest?

2

Hi Scott- post a file with what you’ve got; from your description I can imagine more than one scenario…

thanks,

-Pascal

3

I think you’re looking for the command Sweep 1 Rail… --Mitch

4

I’ll assume stmoen wants to have the triangle wrap around the curve in a helix.

Method to do so:

  1. Create a second curve which wraps around the second curve using Helix with the Around Curve option.
  2. Sweep2 with the original curve and second, helical curve as the rails and the triangle as the section.

Helix Sweep Example DC.3dm (101.7 KB)

5

I rest my case.

-Pascal

1 Like
6

Still taking bets… :smile:

1 Like
7

rotate surface.3dm (56.1 KB)

File is attached. Pretty simple. I just want to rotate the triangle 180 degrees around the curve.

Thanks -

Scott

8

Mitch wins.

Hi Scott - Try: DupBorder on the surface. Then select the arch, and start Sweep1. Select the border curve as the cross section. Once the sweep is complete, use Cap to close the ends off if needed.

Pascal

9

This is the same result that I got before. How do I get the rotation using this method? It would seem to make sense to add a “rotate” option to the Extrude Surface to Curve command.

10

If you want the profile to rotate as you sweep, place a rotated profile at the other end of the path- make sure the closed curve arrows line up correctly as well.

rotate surface_PG.3dm (104.7 KB)

-Pascal

11

Thanks-

This is closer to what I want. I’ll need to find some tutorials on the sweep rail to completely figure this out.

Scott Moen

214-483-7682 (w)

303-906-4449 ©

12

Pascal’s solution does not look twisted to me. Two edges are planar, and the planes they lie in are parallel to the plane of the original curve.

An alternative: rotate surface DC2.3dm (142.6 KB)
Created by:
Helix with Around Curve option, 1/2 twist using original curve and the three vertices of the triangle in succession.
Loft the three helical curves, straight sections, closed loft
Cap the lofted surface
This surface has sections which are the same shape and size as the original triangle.

13

Thanks. This is helpful since I can do more than one revolution which I couldn’t with the previous solution. Sure seems complicated for rotating a surface along a curve!

14

Hi Scott - Here’s another option -

rotate surface_PG_2.3dm (137.5 KB)

Start the Twist command on the straight extrusion - set the axis on the line down the middle, Infinite option set to Yes at the command line, and type in 180 as the amount (degrees) to twist. The straight extrusion is mapped to the curvy curve using Flow, with History recording turned on.

-Pascal