really struggling with this definition

Hi all,

I am new to grasshopper and I have a presentation on Wednesday. I thought it would be easiest to do this in grasshopper, but since I am so new I have run into a lot of problems. In any case- attached are the two files (1 rhino and 1 grasshopper) from which I am working.

Here's my issue:

I have created a piston which can rotate and extend and thereby alter a surface--kind of like running your fingers on a stretched fabric. The problem is, how do I replicate the piston and have control over each piston seperately using the same surface? I would greatly appreciate your help.

Best,

- Augustin