Super 8 sprocket with 20 teeth and 5mm shaft for rigid or flexible coupling.
Each tooth is:
H = 1mm
D = 0.9mm
W = 0.9mm
modulus between teeth is 4.1884 mm, computed on a real sprocket from an old projector.
If coupled with a Nema 17 stepper motor, every frame need exactely 10 steps.
It could be useful in DIY frame-by-frame telecine machines.