How to analyze for torque needed

[blacktie]

I am hanging a pole (made of pvc) on a wall. On the pole will be a roll of kraft paper. I would like to hook up a simple belt driven reversible motor for the purpose of turning the roll to let the paper down then wind it back up.
How do I determine the amount of torque the motor should have to perform the task?

Please be gentle - I googled the random question to get my registration to pass - I have no clue about the science of these things - normally, if they weren't so dad gum expensive, I'd just buy one of each motor and try them til i found one that worked.

 

[Navin A S]

The amount of torque required will depend on several factors, including the size of the roll of paper, the weight of the paper, and the friction on the axle of the motor. Generally speaking, the larger the roll and the heavier the paper, the more torque the motor will need to have. Additionally, if you are using a belt-driven motor, the belt itself can add additional friction and require more torque. To determine the amount of torque required, you should first measure the size and weight of the roll of paper, then calculate the amount of friction on the axle of the motor. You can then use this information to help you select a motor with the appropriate amount of torque for the job.