STORY: Hell on Wheels started as an experiment to see if I could make a fancy molded composite part, instead of the usual flat panels that I'd been making for my research & other bots. I already had enough parts on my shelves & storage bins to make a 12lb bot: batteries, wheels (previously used in BWEI & Dr. Inferno), radio gear, and weapon spikes. When I competed in the 2 previous BotBash events, I noticed that the majority of the bots in the teeny 12lb weight class were toy store remote control vehicles with minor modifications. I wanted to bust through these plastic & cardboard bots with something strong & nasty. Unfortunately, the quality of 12lb bots at BotBash 2001 was very high, & Hell on Wheels didn't do a whole lot of skewering. Hell on Wheels also competed in BotBash 2002 and the inaugural Steel Conflict.

I've used Hell on Wheels for several demonstrations to grade school & high school students, as well as a demo in San Francisco's Exploratorium science museum during a Robotic Society of America sumo competition. Since then, he's received bigger & stickier wheels, some work on robustifying the motors, minor gearbox mounting upgrades, and an all-new weapon.

SPECS: Hell on Wheels is a simple ramming bot with few components: shell, 2 motors, 2 gearboxes, 2 wheels, 2 spikes, radio, battery, & speed controller. The armor/structure is 2 parts molded in a glass Pyrex casserole cooking dish, 2 plies of 0-90 woven carbon fiber/epoxy composite fabric. The motors are revolutionary new prototype versions of the Blackhawk 35 motors from Thin Gap, now available for purchase. With all-new motor technology never before used, they achieve amazing efficiency, torque, weight, acceleration, and speed. Of course, I'm overvolting them a bit, too. The gearboxes are from a Porter-Cable 12V cordless drill. The original wheels were refurbed leftovers from previous bots, but with new paint, new tread, and new tread reinforcement. The upgraded set of wheels was Colson Performa casters that provider wider, sticker tread, higher speed, and the ability for the bot to flip over a full 180°. The first set of spikes was long 3/8" stainless steel shafts with ground tool steel inserts at the tips. The second set of more robust spikes was 1/2" OD 304 SST tubing, the same tubing used in the new spiked mace weapon. Radio's a Futaba PCM rig. The initial battery setup was an 18V 3000mAh Ni-mh BattlePack, but I dropped to 14.4V to go easier on the motors, improve control, and have more weight for the heavier weapon. The speed controller's a Vantec RDFR23.

TECH DETAILS : One of the major problems was getting power to the ground. With a 20,000+ RPM motor, a 56:1 gear reduction, and 5" wheels (later changed to 6" Colsons), Hell on Wheels loves to peel out and burn rubber. At full throttle from a standstill, he pops a wheelie and easily flips all the way over. By making the spikes heavy & so very long, the tendency to pop wheelies is lessened & Hell on Wheels gets pretty decent acceleration. I have to go easy on the throttle, though. Because of the huge power in such a short (front-to-back) package, the bot tends to spin out easily. So, I added a fixed front caster wheel to help it track straighter (when it's not popping a wheelie...). Upgrades for 2002 include a new hammer weapon with 5 drilled & tapped holes for screwing in various spike combinations, a new pair of thicker, longer spikes, smaller 14.4V batteries, a new power switch/radio battery recharging module, more securely mounted motors & gearboxes, minor motor brush modifications, and teflon skids for smoother driving while inverted.

SPONSORS : Super duper prototype motors supplied & maintained by Thin Gap. Nuts & bolts & other hardware from Specialty Tool & Bolt. Custom batteries for drive & radio from Robotic Power Solutions. Machine Arts made the new weapons for 2002.