What determines the rotational speed at which a centrifugal clutch starts to engage?

Question

What determines the rotational speed at which a centrifugal clutch starts to engage?

Answer 1

two things: the mass of the flyouts and the spring constant of the restraining springs.

Heavier flyout weights --> higher engagement RPM.

Stiffer springs --> higher engagement RPM.

Answer 2

w^2/r -- The centripetal acceleration.

At a particular rotation speed, weights attached to the clutch plate will slide out as a result of the acceleration.  These weights (if I remember correctly) are attached to springs.  So in designing a clutch, you can also design the speed at which it will start to engage.

Answer 3

The internal shoes are usually spring-loaded.

Centrifugal force has to overcome the tension.

Then friction on the outer shell has to overcome inertia.

That in turn, has to exceed the load, which is attached.