- #1
Mech13
- 1
- 0
Hello,
I am to use a motor to turn a spool and lift a weight.
The bit that's confusing me is the moments active in this situation.
I would assume that the only torques to consider are the torque exerted by the motor and the torque caused by the weight of my object. I would think that the capstan equation applies in this situation and that the torque needed to pull up the weight would be RSpool*(Weight/e^(Coefficient of Friction*Theta)). However, I'm not sure if I'm missing something. I would like to raise the weight and keep it suspended with some kind of mechanical lock on the shaft. I looked at winches which, unless I'm mistaken, are the same thing I'm describing, but in McMaster the capacity of a winch is shown as less when the wire rope is fully wound. This goes against what I assumed which was that when fully wound it should be easier to hold a larger weight. Can anyone shed some light on my confusion or point out flaws in my thinking? My apologies if this was hard to follow I have included a rudimentary picture bellow. Let me know if any clarification is needed. Thank you.
I am to use a motor to turn a spool and lift a weight.
The bit that's confusing me is the moments active in this situation.
I would assume that the only torques to consider are the torque exerted by the motor and the torque caused by the weight of my object. I would think that the capstan equation applies in this situation and that the torque needed to pull up the weight would be RSpool*(Weight/e^(Coefficient of Friction*Theta)). However, I'm not sure if I'm missing something. I would like to raise the weight and keep it suspended with some kind of mechanical lock on the shaft. I looked at winches which, unless I'm mistaken, are the same thing I'm describing, but in McMaster the capacity of a winch is shown as less when the wire rope is fully wound. This goes against what I assumed which was that when fully wound it should be easier to hold a larger weight. Can anyone shed some light on my confusion or point out flaws in my thinking? My apologies if this was hard to follow I have included a rudimentary picture bellow. Let me know if any clarification is needed. Thank you.