[dekhn]

I've built a similar device to this (originally for a solar tracker that keeps the sun at high magnification in the middle of the frame, but it turns out to be ideal for panos as well).

It's a DSLR with crop sensor, 300mm lens, stepper+gear for azimuth and stepper+belt for altitude (with gearing to get more torque for both). I used this system with Hugin to assemble 180 degree x 180 degree, 5 degree azimuth and altitude steps (so, about 5X your resolution, I don't have the same zoom as you). Results are great- I can give this straight to hugin, update a PTO file with my known angles, and it assembles without any futher optimization. I do pan with a planned path.

If the belts are real tight, backlash is neglible (seems to be a lot smaller than any gear I could print). If you're having that much backlash on tilt (that it's shaky and sensitive) I think you might need to re-engineer the frame to be more stiff (which will cause the shakes to dissipate faster) or tune your motors (tuning velocity and acceleration). You might also be able to use a spring to keep the gear in place. I tried to get a 3D-printed worm gear working, but never made it compact enough to be practical for the altitude.

I had white PLA, in direct sunlight/90F ambient for hours, and it warped. I only noticed because I was inside watching the incoming images and the altitude staged started to "melt" causing massive positional losses.

[encypruon]

Good results without optimization at 300 mm sounds pretty impressive. Maybe belts are the way to go. Thanks for taking the time to elaborate!