Useful as an upgrade or a spare for Hegner scroll saws.
Single speed machines have a standard motor with a double pole ON/OFF switch.
Variable speed machines have a different motor with a shaft encoder and V/S control
With the exception of the industrial rated Polycut machine the motor and switching is identical across the range of Hegner scroll saws
Single speed motors/machines cannot be upgraded to variable without replacing the motor
Hegner scroll saws are one of these variants
Single Speed - with switch under the table
Variable Speed - with dial up controller situated under the work table
Variable Speed - with the speed control integrated into a footswitch controller