Robot loses connection: Any clue why?

[PhilBot]

Hi

This may seem obvious, but I've seen it with rookie teams preparing for competitions on Thursdays.

There are several ways to build a drive system that WILL NOT run when placed in contact with the ground. In most cases when you try to run it, the motors stall and cause a moderatly charged battery voltage to fall to levels where the radio/c-rio resets. This can not be seen on the console.... because the system has reset.

Some things to check for when the robot is in the air:

1) Are all the wheels travelling in the correct direction? (a 4 wheel drive robot with one motor hooked up in reverse will stall instantly.)

2) Is the same gear ratio used on all motors? (Incorrect choice of sprockets will cause the wheels to spin at different speeds. Motor will stall immediatly.

3) Are you trying to skid steer with too much traction, or too High gear ratio? A narrow base robot with traction wheels needs a LOT of torque to turn on carpet. If you can drive OK straight, but fail on turns, this is the likely cause.