Nick Bergh has (IIRC) the only remaining, working 1925 Western Electric lathe with it's full-size rack of electrics. It has a weight-driven motor, you can see it in action in the PBS show "American Epic".Inigo wrote: And using a weight controlled motor?
All the Diamond Disc lathes also have weights, even the few with electric cutting heads.
And they would have been using wax, but throwing the acetate in the trash looks much better on-screen then sending the wax back for shaving