Calculating Minimum Motor Torque for a PVC Pipe Feeder System

[jra12222]

Hi,
I am trying to 'size' my first motor to drive a system. I am trying to make a feeder where a PVC pipe is fed as shown. There are 2 vertical rollers, on connected to the motor as shown and an other coupled to a pneumatic piston to keep the pipe under pressure. the frictional force will be that of 12N while the torque required to overcome the force generated by the piston (assuming a worst case scenario and using F=PxA, and T=Fxr) was 6Nm. The total torque generated by the motor is that of 25.4Nm ( calculated using Power=torque x angular velocity).
While I am assuming that the motor is obviously more than able to overcome the frictional force, is there a way to combine both opposing forces and see the minimum torque required by the motor to overcome these forces?
Thanks in advance

 

[haruspex]

You need the radii of the rollers.
Divide each torque by the roller radius to get the force at the pipe. Add the force the slave roller needs to the frictional force and compare with the force from the drive roller.

 

[jra12222]

OHH damm that was much easier than what I was expecting haha! thanks a lot buddy!