DIYbanter - View Single Post - Help please w/ electromagnetic slip clutch

Jon Elson[_3_]

wrote:

The handwheels turn an encoder that makes a servo motor turn a
leadscrew. I want to monitor the servo current draw and use it to put
a drag on the handwheel. So more work for the servo makes the
handwheels harder to turn.
What you want is a small servo motor controlled by a servo amplifier. The
torque is proportional to motor current. Just take the current monitor
signal from the servo amp, amplify and apply to the handwheel motor.

Trying to do this with clutches or brakes will lead to great frustration.
Only the most exotic clutches and brakes are very smooth, and otherwise
would put a lot of stick-slip friction into a systemw here you really DON'T
want that.

If the main motor is a DC brush servo, it is possible that a resistor can be
put in series with it, and the handwheel motor connected across that
resistor. Then you would not require a separate small servo amplifier.

Jon