I've never seen a lathe with 3 gears for the Threading Dial Indicator. Is that typical for a metric lathe?
Both of my lathes have imperial threading screws. The newer one, I can select metric threads with the change gears, but I can't disengage the half nut. That's a major PITA. I had read about making a new gear for the TDI that would enable doing metric threads and allow the half nut to be disengaged. But I'm not sure if that's true.