[vivek16]

Originally Posted by Pat Roche

I understand your predicament with the hex shafts. A future consideration with gearboxes though, as your stages move closer to the motor their is clearly less torque transmitting through the gears. If you were to run your stress analysis on your gears in your first ratio I'm sure you'd find that you don't need a terribly thick gear for your ratio allowing you to use a 32 pitch gear. Usually in my transmission designs I start small and work my way up in size through the stages of your gearbox. This saves weight by using less steel, cast iron or bronze (depending on the application) in the transmission.
Disclaimer: Always check you stresses before you decide on a pitch size however, there is nothing worse than stripping teeth.

Pat,

I plan on heavily pocketing and cheesing the first few gear stages. The only gear sizes I found for 32 pitch for reasonable prices had 1/8 inch face widths. I am just going to stick with AM gears for this gearbox. Bright side: The 45 tooth output gear only comes in .54 inch face width so I can pocket it like I would the other gears and not worry

thanks, Vivek