I have to start somewhere, so my "actors" occupy an area 14 inches wide by 9 inches high by 5 inches deep. My "stage" is 2 feet by 4 feet (with two 4 inch by 5 inch "wings" to support the photo rail).

To create an animated product, the camera must start and sequence at the same spot every time (48 or 45 photos to represent one "frame" for the stop motion production). I placed a magnet on the photo rail.

A 3d printed bracket allows the magnet to move under the rail.

An Arduino controller senses the magnet position and (with a relay connected to a camera remote cable) takes the photos.

At the slowest speed for the camera rail, my camera (Canon EOS 250D) needed to take about 4 images per second. It would only take 2 per second. I need to slow the rail or speed up the camera--that's my next subject.