Improving the Gingery Lathe

My main concern about the Gingery lathe (PDF @ >>11164) is that it doesn't have a through-hole on the spindle. I also don't see why the bed couldn't be welded from plates. Perhaps one could eliminate the need for a heavy bed with the proper use of a counter-rotating balancing shaft with counterweights and brakes (actuated by an accelerometer on the spindle to simulate the action of the cutting tool against the work piece). This could perhaps allow for a lighter, more compact lathe that's still capable of machining large parts. Another feature that would make the lathe more compact and modular is an adjustable head height to allow the user to change the swing of the lathe and to allow for milling operations (using the head as a horizontal milling head). Like a milling head, this head could be trammable to ensure a good runout despite the reduced rigidity from the height adjusting mechanism (currently envisioning a rack and pinion that's used to adjust the table height on a vertical mill).

Are you aware that Gingery also has a horizontal mill book? I'd go looking there for design inspiration. More generally, I guess footprint space is at a premium for you, and that's why you want a lathe/mill hybrid? I've been there (still am), but this still reads as a pretty risky constraint to me, so think the blueprints through before you invest the time into fabricobbling. Also consider an alternate design; I've never used one, but all the milling attachments for lathes I've read about either add a vertical way attachment to the cross-slide for the table/vise or replace the spindle with a column-like assembly. Perhaps these are the popular designs because they work better. I'd worry that a homemade lathe I have to tram means a lathe that wanders if I'm not absolutely on top of chasing play out of the parts during manufacturing. For parts, if you're going to modernize the head at all you're probably going to replace the ac motor and speed belts with a dc motor, which has its own advantages and disadvantages but will let you mount it and the spindle to each other so they can be moved together. Once you get into building a true hollow spindle instead of turning dead centers I'd also just buy roller bearings. They don't even have to be the expensive spindle ones, just anything ground from hardened steel will beat trying to make your own. A pristine machine without functional bearings is a glorified paperweight, so don't make yourself suffer through being unable to get usable parts out of your only machine tool.

>>11174 >Are you aware that Gingery also has a horizontal mill book? I was aware. Thinking his design was of the vertical type, I didn't consider its relevance in my OP. >More generally, I guess footprint space is at a premium for you, and that's why you want a lathe/mill hybrid? Yes, but also to build a more modular and universal machine tool. I want to remove as many unnecessary constraints as possible to make it easy to modify the length between centers, the swing over the "bed", or some other innovative modification. Basically, like an Emacs for machine tools. >all the milling attachments for lathes I've read about either add a vertical way attachment to the cross-slide for the table/vise I don't like that design, because you are limited by the machine's "swing" what sizes parts you can machine. >replace the spindle with a column-like assembly That's the design I had in mind. If I understand correctly, Gingery's solution for the "tail stock" is an elegant way to ensure the head and tail are at the same height. >just buy roller bearings This. Maybe capping the rollers with balls to handle axial loads.