Simple pipe bending

Hello,

Here is what I have:
I have a long pipe with a fixed lenght.
Along the outer edge of the pipe I have a line with several points.

The points are like magnets. I want to see how the pipe bends and reacts when given points come together. However, I want the pipe to maintain its diameter and lenght.

For some reason the points come together but the pipe never bends properly.

Thanks for tips

Hi Alice -

Please post the .gh file. Make sure to internalize any possible Rhino geometry and to mention 3rd party plug-ins that are used.
-wim