Fig. 3.1: Franklin Mill Motor on Lathe
A motor that can be mounted right on the lathe headstock is a nice, compact approach common to many small lathes. I found such a motor at surplus, a Franklin 36-frame, 1/5 hp Model 1206030400. It turns out that this is exactly the same motor that Taig sells for its manual mill but I didn’t know that at the time. It also carried a Xerox part number so it was, at least for a time, an OEM for them. Franklin kindly provided a schematic showing the Xerox wiring with two capacitors and a starting relay. But it started and ran just fine as a single capacitor, PSC motor. I say ‘just fine’ but that’s not altogether true. This motor runs with perceptible electromagnetic vibration. The Xerox circuit may have smoothed this out or it may just have been damped by the mass of a heavy machine. But as a PSC, when attached directly to the Taig headstock as shown in Fig. 3.1, some kind of resilient mounting is definitely recommended. A simple solution uses small rubber grommets between the motor and mounting plate and is reasonably effective at isolating the lathe from this vibration. I used this layout briefly while developing my next system but never really liked it very much.