So we have a new x-axis stepper that we expected to be more powerful than the previous, but something seems off. The old X axis (and the current Y and Z axis), 425 oz in NEMA23 wired in bipolar parallel to a KL4030, at 3 amps of current. Our ways are pretty tight to eliminate play, but we've been able to move the table and head at 70ipm with 1/4 micro stepping.

The X axis motor is now driven by a 570 oz in motor. The motor is rated at 5 amp, but we've wired it in bipolar series (because the Automation Technologies website said to) so we're only giving it 2.5 amps. We're using a KL11080 driver. The x axis, no joke, now can be pushed at 375ipm! 1/4 stepping as well. It could likely go faster, but it can't get up to speed before it runs out of travel.

Normally I would be excited, except that the motor gets warm, even while idle. Not so warm as to be uncomfortable, but notably warm still. With my other motors, I never once noticed a stepper to get even slightly warm. So either

1) My new motor is getting too much of something and is on the highway to meltsville, or

2) The heat is normal and my other motors are under powered, hence less/no heat.

Can anyone shed some light on this?

The mill is an SX2.