Hi guys,

Jonathan, if you are genuinely willing to machine two rotating ball-nut/motor mount things for me at a good price then I'll go for it :)

I'm sorry to be persistently stupid but I still don't understand the desire for 10mm pitch. This is my thought process: Two screws with the same pitch, turned at the same RPM, will give produce the same speed and distance of movement. In practice, one axis will have a greater load than the other, so it will need more torque for the screw to maintain the same RPM. However, with adequate torque (two screws, two motors) there should be enough torque to do that. In fact I'd expect a larger screw pitch to need even more torque. If the 10mm screw moves twice the distance with one turn, it will require twice the force to turn it, not to mention the greater mass of the load.

Where is my thinking going wrong?