Re: [CAD_CAM_EDM_DRO] servo motor replacement

dkmach2 wrote:

> I need to replace the servo motor on a tree j300 milling machine.
> What specifications do I need to be concerned with? Which ones can
> vary without problems?

Well, I'm assuming this is a permanent-magnet DC servo motor. What you
need is a motor with roughly the same kT and kV. kT is the torque constant,
or Oz-In/Amp. kV is the velocity constant, or Volts/1000 RPM. Another
constant is the maximum peak current. If you know how to reset the
current limit on the servo amps, then you can use a motor with a lower
peak current rating. If either the kT or kV are much different, or the
inertia or electrical time constant are very different, you will need to do a
complete servo tuning procedure, which takes some special equipment
to do right.

If you can do the servo tuning, then almost any motor that can reach the
speed necessary for your rapid feeds with the power supply voltage available,
and a kT such that the amp, at the amp's current limit, can deliver enough acceleration
to keep you happy.

Jon