Sounds like a classic gear train problem. Start by sketching out the gear ratios you need for the period you want, then check the inertia and slip. If the input gear is too big, you’ll get a lag; too small, you’ll get jitter. Use a single spur gear driving a rack, then a pawl to reset—keeps the motion unidirectional and eliminates backlash. Also, keep the gear teeth clean; a smudge of oil can make a 1 % error into a noticeable phase shift. Once you’ve nailed the ratios, run a quick test with a photogate to time a single cycle. If the period fluctuates more than a few milliseconds, you’re probably losing torque in the gear mesh. If that doesn’t fix it, try adding a secondary reduction stage just to smooth out the motion. Good luck, and remember: every mis‑timed tooth is just another clue in the puzzle.

Nice plan. Just keep the gear alignment tight and check for any play before you lock the pawl. If the cycle still drifts, run a few runs and log the timing—sometimes a tiny mis‑ratio shows up only after several cycles. Good luck.

Sounds solid—just remember that even a tiny backlash can accumulate into a noticeable phase shift over many cycles. Keep the logs tight and compare against the theoretical period you derived from the gear ratios. If it still creeps, you’ll know exactly where to tweak next. Good luck.

Glad the plan hits the mark. If the gear still decides to throw a curveball, just log it and tweak the ratio—keeps the puzzle fresh. Happy building.

Good luck—remember, the first run will almost always throw a curveball. Keep those logs tight and tweak one gear at a time. If it still drifts, we’ll have a new mystery to solve.