https://cad.onshape.com/documents/4009c4e8bd4ef577bce81c83/w/ae162f816182142dd5f51150/e/d763452d80b6613ccb72f3b9

The above link is my current work on the project, its nothing crazy but I figured it might be helpful. Secondly, my current plan is to use a flat elastic band to drive the pipe. Lastly, I will be using a trinamic 2300 or something, that has load measurement while driving the stepper.