I'm trying to build a kinetic machine that rotates socket ratchet tools (e.g. https://en.wikipedia.org/wiki/Socket_wrench) to make a bunch of ratchet 'clicking' sounds for an art project. I'm trying to determine the proper stepper motor to do the job so I'm mostly looking at how much torque will be required. I just wanted to go through my calculations to see if I'm estimating the required torque properly. NB: keep in mind I'm not taking into account the friction imposed by the socket clicking mechanism....
I'm modeling the ratchet as a lever with equally distributed weight (M=1.4 kg) and of Length=R=0.475m) to calculate the moment of inertia for a lever: I = (1/3)MR2 = 0.089 kg-m2
If I want to be able to rotate the ratchet, I have to apply acceleration to get it moving from rest. I want it be able to make one rotation per second. alpha = 1(rev/s)*2$\sf\pi$/1s = 2$\sf\pi$
Therefore, I'm estimating that the torque needed to get the ratchet to start moving would be T >= I*alpha = 0.56 N-m . Does this seem right?
Also, I'm wondering how I can reduce the torque constraint. For instance, if I attach an arm appendage to the shaft on the motor so that its pushing/rotating at the edge of the socket wrench, it seems like this would significantly reduce the required torque? How would I factor this into my calculation?
Any advice would be super appreciated! many thanks in advance!