Re: High-Low gears [TANKS]

["erik kump" <ebkump-at-hotmail.com>]

>From: Frank Pittelli 1) use a fixed transmission and vary the voltage to 
>the motors,

I thought about this one first, but it is working backwards from what I 
want. If I understand correctly: A specific gear ratio running at 12v will 
produce X rpm's and Y in/lbs of torque. If you switch the same setup to 6v, 
then it produces 1/2 X rpm's and 1/4 Y in/lbs of torque. Conversely, 
switching to 24v will produce 2 X rpm's and 4 Y in/lbs of torque. So 
lowering the voltage to gain a lower speed range actually reduces it's 
ability to handle rough terrain.

>2) use a fixed voltage and transmission, and vary the motor windings,

I'm not sure what you mean by this.

>In both cases, however, the key to success is finding the right 
>transmission ratio(s) for the motors/batteries/tracks/vehicle being used, 
>under the expected loads.  In theory, the ratios can be calculated, but at 
>some point you have to simply put it on the field and measure the 
>performance to truly find the optimal settings.

Good idea. I don't know the speed capabilities of the average operational 
tank though. Do you think my speed ranges would be a good starting point to 
aim for? 2-3mph for low gear, 4-6 for mid, and 8-10 for high? Thanks for the 
input,

Erik 'speed demon' Kump