Rope turnings in wood.

I am new to this group. Some here may have seen me post this question in other groups.

I want to do "rope" turnings in wood on a metal lathe. I plan to use shaper blades on a spindle to do the cutting. The foundation of what I want to do is to couple an encoder and a stepper. the encoder will be on the spindle and the stepper will be on the longitudinal(carriage) to drive them in sync. I need a user adjustable ratio to vary the pitch of the twist. yes its a lot like threading but the ELS wont work. it requires a minimum rpm and relies on a count once per rev of the spindle. it becomes less accurate the more coarse the twist of the "rope"(thread) becomes. The second problem I have is one of power. all of the DIY drivers i have been able to find are for less than 7-8. I have a motor rated at 9 amps 2.5 v per phase 900oz/in I figure I will need at least 600oz/ins unless I want to get wild on the reduction side of the drive and then I will have trouble fitting it under the cover on the headstock. I would really rather not go outboard with a drive.I have been to the commercial sites and know I can buy a driver for the motor but that's not why I am here. I have been told to run the motor with reduced power. I need the power that's why I have the motor!

Anyone got a handle on the electronic side of this? coupling actually two steppers with a handwheel input and being able to input a ratio between the two outputs for the drivers.