So, as I like to shoot semi-high resolution panoramas and partial panoramas, I've been looking for a way to automate at least part of the process.
My first attempt, bolting my NN3 to the stepper motor shaft ended with a slightly less straight shaft. Thankfully, after reading the description of the new rotators for the NN5, I realized that a similar idea should work for a stepper drive. So, with a 1.5" ID thrust washer, a 1.5" OD x 1" long piece of aluminum, I made a coupler for my stepper motor, and a place for the NN5 arm to ride.
Initial tests are promising, I can get apparently back to almost the same pixel coming from the same direction and the same previous location. Coming just from the previous direction I'm seeing errors of about 6-10 pixels(85mm lens, Nikon D70) or about 0.02-0.6 degree error.
Absolute step size, which should average out to 1.8 degrees for this motor, varies by about 0.3 degrees. So I'm probably not going to be able to stitch using a template, but at least the shooting will be automated, and provided the automated control-point generator isn't too horrible, the work should be easy.
The next iteration will be to add a plate for the NN5 lower arm to ride on so it's not directly on the thrust bearing. Then a way to make it portable. Then maybe a worm drive, and then maybe a tilt axis worm drive... many months in the future.