Pauly,
The flywheel effect of the platter on that cutting lathe would be negligible compared to the 75kg/cm torque generated by the motor. From pictures on the net it's evident that a really decent cutting lathe like the Neumann has a much stronger drivetrain. A lathe strong enough to handle the fundamental drag on the cutting tool should be impervious to small modulations in drag. Still, somehow tools never quite seem to be as good as they should be. I have a metal lathe with a 10" chuck & a 2hp motor & I still manage to find jobs that are too big for it.
I did find a reference to pitch problems introduced by stylus drag on lathes used to cut 78rpm records in the 1920s.
The flywheel effect of the platter on that cutting lathe would be negligible compared to the 75kg/cm torque generated by the motor. From pictures on the net it's evident that a really decent cutting lathe like the Neumann has a much stronger drivetrain. A lathe strong enough to handle the fundamental drag on the cutting tool should be impervious to small modulations in drag. Still, somehow tools never quite seem to be as good as they should be. I have a metal lathe with a 10" chuck & a 2hp motor & I still manage to find jobs that are too big for it.
I did find a reference to pitch problems introduced by stylus drag on lathes used to cut 78rpm records in the 1920s.