Quote Originally Posted by jarjar View Post
A 400W servo (rated at 1.2Nm @ 3000rpm) is plenty enough. 200W is also probably enough.
I will be using a Yaskawa 400W servo with brake for a 60kg Z axis (moving part only), driven by a 5mm pitch ballscrew @ 1g accel and 20m/min.
The servo has a peak torque of 4Nm, and moving this axis will only require about 2Nm peak.
In post #2 http://www.mycncuk.com/threads/13448...672#post114672 you said that these 180W servos that I had bought were only toys and that 400W would be the bare minimum. I think you were talking about a little bit different design in that case so I can just ignore it, correct? Anyway the price difference between a Delta 200W servo and a Delta 400W servo is minimal.

Will you be using direct drive for that Z-axis? I checked that those servos are rated at 3000rpm, so direct drive with 5mm pitch would result in 15m/min. Also what diameter will that ball screw be and is it possible to spin it that fast?

Your moving weight sounds extremely heavy! Are you designing it in steel? How did you calculate how much Nm will be needed to move the axis?

Wow, this turned into a lot of questions, lol!