dc motor

I have two machine restorations going on that I'm unsure what route to take so I guess I'm trying to lean on the community for input, but unfortunately I think the questions have a little bit of the chicken and the egg quandary inherently built in, but what route should one take when breathing...

I finally got my TH/QC54 lathe dc motor conversion done, and up and running! I did some practice turning on a scrap piece and all seemed to work fine. Took into making my first actual part, a small shaft .390 diameter CD steel. I made a number of passes on the part, when the motor speed...