This weekend I built two 1 pound [454 gram) r/c bots intended for competition at MURC or a Sozbots event. Note: as of 2010 these competitions do not exist.
These little guys use a highly modified Battlebot toy as a platform, which are actually very easy to work with to make something unique, but inexpensive.
Plane-Jane has a carbon fibre plane on the front and has been rewired to disable certain features that are part of the toy and the dry cells have been replaced with Ni-Cads. I had to add a steel bar under the plane to get the weight up , but it is still underweight at .9 lb [411 gm]
Blizzard has a 4130 chromolly steel 'snow' plow on the front. The plow itself is 3/8 of the overall weight of the bot. You don't want to catch this when it falls of the dinner table as the plow blade is really sharp. The holes in the 3.2mm thick plow are to help bring the bot into weight compliance. The front was originally the rear of the toy, but the motor controller was rewired to get the forward direction and steering modified to reverse the direction. It has also has been rewired to disable certain features that are part of the toy and the dry cells have been replaced with Ni-Cads. The front extension aand battery compartment was cut off and the new Nicad batteries were mounted over the wheels. The toy's wheels were replaced with wheels from the on- linline Sozbots store.