Best servo for SLOW rotation

I'm trying to determine what AB servo is most appropriate for slow but smooth rotation speed. In the past we have dealt with other servo brands and drives. The sinusoidally commutated motors are the smoothest at very low rotation speed (e.g. < 0.5 RPM). But I can't find anything in AB literature that indicates whether AB servos or drives are sinusoidally commutated, so I'm a bit worried they are not smooth at such low speeds.

By the way, we're looking at something in the 1.3-5 Nm rated torque range, depending on the gearing we choose downstream later.

Any input would be appreciated.

John

Why are you stuck on a servo?
you can do that with a Flus Vector drive
I have a system running a weld bead at less then 1 hz using a Flux Vector drive
the weld bead is perfect
just use a high ratio gearbox with a 5000:1 ratio you should have no problem

I'm not familiar with all the capabilities of the flux drive. But if it can use encoder feedback it may be possible. I need the encoder for position control, back and forth. Also our gearbox will be more like 20:1 or less in order to hit the high speeds we need as well as low. I can't go to 5000:1, or even above 100:1. I'm trying to strike a balance in rapid homing/return over long distance and very steady, slow movement.

The other factor is that we're replacing a servo in there now... I was hoping to find one that bolted right in with little modification.

John

John
I apologize I did not make myself clear
The 5000:1 is the stable speed range of the Flux Vector drive system ( motor with encoder and VFD using encoder feedback)
An 1800RPM motor can run as slow as 0.4 RPM and be within the operating range.
You can then couple that with a gearbox of any ratio you want to go even slower.
A 20:1 gearbox would reduce the final speed even more giving you a very low final output speed.
This configuration will be a lot cheaper than a servo system and in most cases you will not see a difference in performance.
As for positioning with a high pulse per revolution encoder you should have no problem with positioning either.
I have actually used a Flux Vector system to hold a load as zero speed ( This depends on the VFD and Motor used )
If you want more details pm me.

Gary