Nickeldave wrote:I have Shopsmith #191428
I would like to slow it down some for turning.
I'm not interested in spending over $1000 for the upgraded head.
My thoughts are I could use a router controller to slow it down.
I'm sure this is a bad idea but wanted to know what y'all thought.
Router controllers won’t work with an induction motor, which is what powers your Shopsmith. Induction-motor speed is controlled primarily by the supply frequency. Variable-frequency drives (VFD’s) do indeed change the supply frequency to the motor — but they are only suitable for three-phase induction motors. The starting circuits on single-phase induction motors aren’t compatible with VFD’s.
Router controllers effectively change the voltage applied to the motor. This enables them to control the speed of “universal” motors. Or to dim light bulbs. Or to “release the magic smoke” from an induction motor.