Helix around a spline 1

[PSI-CAD]

Have a look at the flexible part. The angular value gives a wrong result when over 720°

So, I would like to create a guide curve around the circle

There is no option in helix function to create it around a spline instead of a linear direction.

Does anybody have an idea with a law function ?

Thanks in advance
Didier

 

[RobLN]

I'm guessing that the problem is the flattening out of the shape that you don't want.
Here is a law curve defined shape you can control the rotation of the coil with the angle expression. Not one of my models but I found useful in trying to understand how law curves can be set up.
This works great with a round tube - not so great with a half tube
Maybe someone knows how to control the relative rotation of the half tube to run it consistant with the guide string so its not all wobbly...

 

[PSI-CAD]

I just found by myself the solution with project arc length function.
Have a look at the part flexible.prt
Didier

 

[RobLN]

Hi thats a good solution. I'd not spotted the face normal option within the swept command.

Thats a good way to create the spiral with the projected curve. Thanks for sharing the model. I'm sure it will come in useful in the future.