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SpEEdyBL · 09.10.2006, 06:24 PM

You can actually use any gearing for the mamba max motors (unless they over heat). It just depends on how fast you want it to go. If you want it to go 40 mph, you just find what size pinion will get it there, given the motor rpm. So 5700 x 11.1=63270 rpm. 81/12 x 2.6 = 17.55 FDR
Multiplying the RPM at the wheel by the tire circumference in feet and dividing by 88 gets you to speed in MPH.

Assuming a tire circumference of 1 foot, 63270/17.55 x 1/88 = 41 mph.

Calculating speeds above 40 mph gets a little hairy because you have to consider the voltage drop constant of the battery, the rpm drop constant of the motor, the number of amps that the motor pulls and tire balooning. Tire balooning is the most difficult to calculate.

	(#4)
SpEEdyBL "Out of spec" enthusiast Offline Posts: 820 Join Date: May 2005	09.10.2006, 06:24 PM You can actually use any gearing for the mamba max motors (unless they over heat). It just depends on how fast you want it to go. If you want it to go 40 mph, you just find what size pinion will get it there, given the motor rpm. So 5700 x 11.1=63270 rpm. 81/12 x 2.6 = 17.55 FDR Multiplying the RPM at the wheel by the tire circumference in feet and dividing by 88 gets you to speed in MPH. Assuming a tire circumference of 1 foot, 63270/17.55 x 1/88 = 41 mph. Calculating speeds above 40 mph gets a little hairy because you have to consider the voltage drop constant of the battery, the rpm drop constant of the motor, the number of amps that the motor pulls and tire balooning. Tire balooning is the most difficult to calculate. Check out my custom converted 8ight: Sub 7lb, lowest CG of any 1/8 buggy http://www.rc-monster.com/forum/show...894#post367894 Area 52 Ranch Raceway T.R.C.R.