Sure, let’s get into the numbers. If your pocket watch ticks at 18 beats per second and you want the espresso to finish in 25 seconds, that’s 450 ticks total. To get 450 ticks from a 18‑tps watch you need a gear train that slows it to 1 tick per second. A 1:18 ratio works, but you can also use a 2:36 ratio to keep the teeth count manageable. Keep the gear teeth even, use a light oil, and test the timing by running a dummy cycle. I’ve got a few old watches that still tick perfect; just remember: the moment of extraction is the moment of the tick.