1. What would be your recomendation for the torque rating for stepper and sevo motors if the motor is directly connected to the ball screw without reduction in order to avoid any lash from the reduction system ?

2. What be the recomended motor speed ? 1500, 2000, 3000, 4500 RPM's

Thanks in advance for your precious advise.

Daniel.

Daniel, Unfortunately your question is equivalent to 'How long is a Piece of String'
Way too little information.
I would suggest for insight into the mechanics required, play around with one of the free motor sizing programs like http://www.motionvillage.com/motioneering/index.html
Your question 2/ also depends on the mechanics which will decide the size (dia/lngth) of the ball screw and how fast you can operate it.
Al.

Sorry Al, I forgot to mention the application.

I am looking forward to find a Bridgeport or Bridgeport clone and modify it.

In Parrallel I would like to get the motors and their drivers, I already go a DeskCNC controller and the software.

I went through all the threads. Looks like a 1500 oz.in Stepper or 560 oz.in Servo should be fine as diredct drive, can you agree ?

If it is the case which type would be good from the nominal speed types I mentioned above.

I guess ball screw should be 5mm or 0.2" pitch. from what I could read, 3/4 or 1" screw size should be fine ?


Thanks in advance

Daniel.