Final Ratios & Gearbox Info

Agreed Upon Specs:

2 Speed with Power-Take-Off (PTO) for Winch

4 CIM motors, 2 per side

Initial Reduction – 12:45

High Speed Reduction – 30:48  gives ~15.5 fps at 93% efficiency

Low Speed Reduction – 14:64 gives ~ 5.5 fps at 93% efficiency

All gears are AndyMark except for the 64 tooth dogged gear, 45 tooth intermediate gear, and the 30 tooth internediate gear, all of which are standard Martin gears.

The PTO shaft sits above the intermediate shaft and has one speed, and an the option for two with the addition of another three position piston.  We also have the option of disengaging the output to the wheels if we use another three position piston.

Options Clarified:

1. Wheels move when winch is engaged – two standard pistons required per gearbox

2. Wheels do not spin when winch is engaged – one standard piston, one three position piston

3. Wheels spin when winch is engaged, but winch now has 2 speeds – one standard piston, one three position piston

4. Wheels do not spin when winch is engaged, and winch has 2 speeds – two three position pistons

The cost of the three position pistons is ~$70.  The cost for the standard piston is ~$20.  The gearbox will be designed to accommodate any of these options without the need to change ratios, plates, shafts, etc.