Greetings All, I am working on a project in my shop that requires constant tension on a nylon cord. The cord comes is pulled off of a spool a certain amount and cut. I have drag on the spool because I don't want it keep spinning when I'm not pulling. But pulling against this drag is tiresome. So I was thinking that I could use a motor to help pull the cord. The motor would not have quite enough torque to pull the cord off of the spool by itself. But when I pull on the cord it will be easy because the motor would be helping me. I'm wondering how to control the torque of the DC motor. I think that if I keep the current limited to a certain value the torque the motor can develop will also be limited. If the voltage to the motor is set at a certain value then it will only be able to reach a certain speed. If I set the voltage so that the motor will spin fast enough to keep up with the maximum rate at which I pull the cord will I be able to pull the cord slower without having the motor try to feed the cord too fast? I'm hoping I can just use a current and voltage limited power supply to do what I want. One drawback I see is that when the cord is not being pulled the motor will be stationary but will be consuming power because it is pulling against the drag on the spool. So I would need to use a motor that could be stalled forever without overheating. If a brushed motor is used will this be really hard on the brushes? And could a brushless motor be used instead? Thank You, Eric
- posted
9 years ago