Ball screws are nice but expensive. We have more

friction and reduction

so I hope this does not happen to us. I would

hate to have to readjust

the prop if the RPM creeps up.

Is that Pittman motor a permanent magnet motor?

If so, design a provision in

the circuit to short the motor.  That will 'brake'

the motor and prevent it

from rotating.

Marc Pedings

Thanks Marc. Good idea. I will bet that will works
on yours too Jeff.

Paul Lamar

Vance Jaqua wrote:

I agree that ball screws are over kill, and actually
have significang disadvantages for this application.
They are by neccessity rather coarse in pitch - a
finer pitch V thread is irreversible and will require
less reduction on the motor drive - the system will
have torque to burn. Also many actuator motors are
equipped with magnetically opened drop out brakes for
minimizing over run and non reversal power off. - Vance

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