The fastest set of stock ZZMT gears are the orange ones at about 16:1. Would you be interested in something potentially faster than that? Think you could remanufacture some ZZMT and ZZSE gears?
I'm working through the theoretical part of the gear combinations, testing for the practical results. Here's what I've accomplish on the first try: 11.8:1.
The motor pinion gear: Cut down a ZZMT green transfer gear, saving the 8-tooth part. Enlarge the hole just enough to accept the insulation stripped from a piece of no. 24 or no. 26 electrical wire. Press the insulation in the hole and the gear onto the shaft of your favorite motor.
The transfer gear: Enlarge the hole in a ZZSE red gear so it fits snugly but rotates freely on the existing transfer gear pin.
The idler gear: The pinion gear drives a blue ZZSE transfer gear, which in turn drives the red ZZSE transfer gear. With the motor mounted and the red gear in place, determine the location of the blue idler gear. Drill into the chassis and use your favor method of attaching the gear (I'd recommend a machine screw so the gear may be easily removed for later experimentation). Only the 18-tooth part of this gear is used, but there is no need to remove the 6-tooth part.
The axle gear: Use a ZZMT green gear--no modification required.
Between the chassis and both the idler and transfer gears I placed two no. 2 washers as spacers. Gear mesh was great in all cases and the assembly runs smoothly.
Flip the motor in the well so it is upside down.
A tutorial, with pictures, will appear on my ZZ website in several days. It will include all the theoretical calculations for this particular mod, as well as images of the gear locations. That will be later followed with other mods of this type, including one at 9:1.
chilli
www.gcrossett.com/zipzaps/