Consew Spindle Motor - MitchBradley/Taig-Mill-and-Lathe GitHub Wiki
Consew Motors for Taig Spindles
Consew and similar sewing machine motors are popular as spindle motor upgrades for Taigs. They can be purchased on Amazon and other places for less that $150.
You can replace the foot pedal with a potentiometer but you must be careful of the wiring because the Consew speed control input is not ground-referenced, but rather is riding on a DC potential of about 160V. The voltage between the control leads ranges from 1.7V (motor off) to 4.8V (motor fully on), but the common mode voltage is 160V. This means that you must use a galvanically-isolated interface between your machine controller and the Consew control box.
Options for speed control isolation
Gecko Opto-isolated 0-10V Analog Output
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Commercial Signal Isolator Board
The KBSI-240D signal isolator board is popular for this purpose. It is adjustable gain so it is easy to configure for the voltage range that the Consew control needs. It can often be found used on eBay for about $35 or less. The only disadvantages are that you need space for it (about 1.5" x 5" x 3") in a well-protected (to keep fingers away from high voltages) box, and it requires a 120VAC supply.