pic: Ira's Senior Project

[Sylvia]

Ok, so I'm new to 1712 (as you know, Ira). Next year I'm going to be one of the team members using "Runt" to learn. I have to know next year's robot's drive's expected behaviors before testing (i.e. speed, torque, amp draw, etc.)
Kressly had me review Ira+Andy baker's calculations with me, changing variables and such to force me to learn (which is good, as I know NOTHING)

Here are my primitive calculations. Did I screw up?

The robot speed @ normal load = 4200 RPM
Gearbox Ration is 12.75:1
Gearbox to Wheel Ratio is 1:1
Wheel Diameter is 4 inches.

I was asked to change to a 24-tooth sproket on the output shaft of the gearbox, making the gearbox to wheel ration 2:1, then change the wheel diameter to 6 inches. My calculations were:

4200 RPM / 12.75 = 329.4117647 RPM output
329.4117647 x (2/1 gearbox to wheel ratio) = 658.8235294 = RPM wheels are driven at
658.8235294 RPM / 60 = 10.98039215 RPS (duh)
Circumference = d(pi) = 6(pi) = 19.44
10.98039215 RPS x 19.44” = 213.458823396 in/s
(213.458823396 in/s) / 12 = 17.77 ft/s