This is the third generation of this design that I built. The first weighed 60lbs, the second exploded in testing and the third has survived Motorama 2011 with almost no damage.
Generation 1 is pictured with caution tape decorations
Generation 2 is shown in pieces
Step 1: Design
The new build uses waterjet cut 7075 Aluminum to create a strong, light chassis. The chassis was designed in Solidworks and sent out to teamwhyachi.com for cutting. Using this method meant that when the chassis components arrived it was essentially a large metal jigsaw puzzle.
The machine uses primarily off the shelf components for the internals. The drive motors are modified 18v dewalt drill motors with matching gearboxes, the weapon motor is an Ampflow A28-150 DC motor, the drive motor controllers are Holmes Hobby BR-XL controllers, the weapon controller is a IFI Victor 885, the radio system is a Spektrum DX6 tx and BR6000 rx, and the batteries are custom A123 packs, all of which are available in the used form or newer form in the case of the radio equipment online.
The top and rear armor is a custom composite layup made of Zylon. It is three layers thick and the layup was done on an open mold made of plywood and car body filler.
The image of the electrical diagram shows a simplified version of how the wiring was done in Moros. As it shows, the drive and weapon are on independent power, this is to avoid serious voltage drop to the receiver and to allow a lower cell count battery to be used on the drive side for reduced weight.
Step 2: In use
The robot competed at Motorama 2011 in the 30lb weight class under the name Moros. It finished with at 2-2 record and is still fully operational.
The video below is of one of its fights at Motorama-