I am using servo and stepper motors for the first time, and have been searching for a solution to this basic problem:
I want to drive a shaft with a motor, whereby this shaft also has a ‘neutral’ state that can be switched on/off with a microcontroller. In this neutral state the shaft should spin freely, without any friction or resting torque from the motor.
This is any extremely low RPM application, so a precisely balanced solution is not needed, however a low weight/volume solution is preferable. I am currently using a small servo (35 x 16.9 x 32mm) with a max torque of 4.2kg/cm.
The simplest solution I could think of was to build a primitive clutch, whereby one or more solenoids bring a plate that is attached to the motor into contact with a plate that is attached to the shaft. If there is an existing off-the-shelf solution or alternative mechanism that anyone can suggest I would be very grateful to hear your thoughts.