Rookie team drive tream idea

[Max Lobovsky]

Team 1257 (Parallel Universe or something like that.... don't ask me, I just build the thing ) is a rookie team this year without too much mentor support. We have started to settle on drive train idea but i have a few questions that no calculation or estimate could answer us well. We plan to use one Chiaphua per side (in a tank type steering system) in a four wheel drive with identical wheels front and back. We want to use a worm gear to gear it down about 15 times then a sprocket system for an additional 1.8 or so for a total of about 27. Assuming the the Chiaphua can give us 4000 rpm while driving the robot, that should give us a max speed of something like 8 ft/s.

1. Are two Chiaphua's sufficient to drive it and reach this speed?are the drills better for this situation?

2. Is it worth it to try to assemble the worm-gear-to-spur-gear gearbox ourselves (keep in mind it will be mainly students with access solely to drill presses and other basic power equipment), or should we buy it? If we should buy one, where do we get a gearbox like this for a reasonable price (I was thinking the seat motor, thats a reasonable price )?

3. Will the 12" pneumatic wheels provide sufficient traction?

4. Will tank type steering with wheels be possible when our robot has a relatively large aspect ratio (something like 1.5:1, assuming wheels are about at the corners of it)?

5. Any other suggestions?