How to connect my propellers to my drive shaft? and collet gripping force?

Question

Okay so just to explain my problem. I have a central shaft that has two belt drives connected to it. Each belt goes to a propeller on either side of the drone. I need to connect the shaft that is being spun by the belt to a propeller. I'm using the APC 13x6.5 props. The parts I need The shaft that is being driven by the belt, and a means to connect that shaft to the prop. I was on the motionrc website and it seems to me that it would be much more difficult to use one of type a,b, or c adapters, so I thought about a collet. Now if each prop is making 6lb of thrust, I want to make sure that the gripping force of the collet is sufficiently high enough. I was wondering how I could go about this. I understand I need to calculate the strain, as a result of the applied force used to tighten the collet, but for that, I would need deflection, so I'm stuck. Can I get some steps and explanations on how to calculate this?

By the way, the thrust from each prop is around 6lbf.

Answer 1

In general, collets provide plenty of grip for propellers.

To calculate the clamping force, I think you could take the torque you apply when tightening it, multiplied by the pitch angle of the thread, multiplied by the angle of the cone in the collet.

Then you could turn that into a maximum thrust with the friction coefficient, which you could probably look up.

Or you could just measure it. Do up a collet, and hang weights on it until it comes off.

I don't think you need to calculate strain. That's how much things deflect under a stress.