Carlberg Creations

Heavyweight OverKill OverKill Gallery	Name: OverKill Type: Wheeled Weight: 204 lb Power: Electric Weapon: A really big blade! Sponsors: C2 Robotics, RF Ballard and Son Status: Primed for Vegas 2000!
The Story of OverKill Introducing the newest team members, Frank and Mike Ballard! Two wheel wedge robots are usually simple. Two DC motors, two wheels, one Vantec speed control and a frame that resembles a cheese wedge. They are pretty darn effective but usually boring. I built Toe-Crusher as an attempt to build a wedge that had a little more kick to it. Namely, a wedge with an overhead war-hammer. Toe-Crusher had modest but succesful results; it took Second Place at the 1999 BotBash and came in Fourth Place at BattleBots Long Beach 1999.
The concept was proven, but I wanted to scale it up. The next step was Slugger which I built with the help of Luke Khanlian and Jason Bardis. Jason took some early video footage of Slugger, which showed promise. Sadly, at the BattleBots Vegas Event 1999 Slugger did not perform so well. But I was not discouraged.
I learned a few things from Toe-Crusher and Slugger. Toe-Crusher had a single spike that whacked back and forth and although it was fun to watch it was very difficult to hit a target. I needed a less accurate weapon, something with a larger "danger zone". The motors on Slugger were not directly coupled to the wheels but rather went through a chain. Slugger kept throwing chains and I decided that direct-drive was the way to go.
So I wanted a two wheeled robot with a larger over the head weapon, a wedge, and a more reliable (direct) drive train. I got the wheels (sporty golf-kart tires) from my buddy TJ at Tires Unlimited, I found the perfect motors from Surplus Center (1-800-488-3407) and I got big bearings from Applied Industrial Technologies. The final touch was deciding that a really, really large knife blade would make a really, really cool weapon.
OK, so I had two motors, a couple of monster bearings (for the wedge), tires, batteries, and electronics. Now I had to put them all together. I was going to build the body the same way I built Slugger's body- two main plates with everything hanging in between. However, the real trick was how to incorporate the giant bearings (for the wedge) and keep everything under 210 lbs.
That's where Frank and Mike Ballard and their CNC shop comes in. The best way for a beginner robot builder to loose weight is to punch a lot of lightning holes into everything. The best way for a robot builder with money is to go to a CNC shop and have them "web" all your aluminum pieces. Webbing is a way to hog out a lot of aluminum and keep optimal support and structure. You could do it by hand, but it would take weeks versus days. So I originally hired RF Ballard and Sons CNC Machining (661-252-6730) to make me some pieces. A funny thing about building robots -it's highly infectious. It didn't take long before father and son became interested in seeing this project all the way through. Also, it didn't hurt that I had a cool concept for a robot.
Things were tough (at the time I was building the new and improved super-heavyweight Minion with Brian Roe) but working with Mike was great because he explained to me some of the tricks you could do with a CNC machine and working with Frank was great because he had so much experience and knowledge.
Eventually the body was built. I weighed the body with wheels, motors and batteries. I now had a ballpark figure for the weight of the blade and could go ahead and design it. In my mind there was only one important functional part to OverKill -getting the wedge/bearing system to work properly so that the robot had both a wedge and a hammer.
As far as looks, OverKill depended on two things -the wheels and the blade. I had to find good looking wheels and the golf-kart tires fit the bill perfectly. I spent a good amount of time with the blade. I drew a few versions on a cad program before settling for a style I thought would look good and integrate well to the rest of the robot. I bought a rectangular remnant piece of 4130 steel from Burbank Sheet Metal (818-846-0316)and the same day brought it over to Charisma Design Studios (818-252-6611) along with the cad program to be watercut. Watercutting is a great way to cut shapes out of plate metal. It's fast, realtively cheap, and it doesn't leave much in the way of surface stresses in the material. I picked up the blade from Charisma a day later and dropped it off at a heat treating plant. They heat treated the blade overnight and the next day I picked the blade up and dropped it off at Burbank Black Oxide (818-845-2654) to give it its final black-metal look.
All this running around tied me up for about three days and Mike and Frank were very anxious to see the robot running. Like I said, it's funny how hooked people get! When I finally showed up with the blade they both aggreed it was worth the wait. Mike quickly made a mount for the blade to attach to the robot with his own stylized touch (you'll notice a scalloped cut to the mount). Meanwhile, I finished building the battery pack and wired the robot up. We were done!
We went out into the parking lot to test OverKill. It was one day away from the competition. Was it going to work the way I figured? It had to, we ran out of time. It worked better than expected and before I knew it Frank (Mike's Dad) had me in a bear hug and was jumping for joy. Frank needs to shave more often. Coming soon -how OverKill did in San Francisco.