Robotica - Builders Bios -- The Learning Channel (TLC) -- Robot Competition

Biography: Team Run Amok

Specs: Run Amok's chassis actually started life as an old, discarded riding lawn mower. The electric motor came from Germany, the speed controller from England, and the radio gear and monster steering servo from Japan. Run Amok was built for speed and maneuverability, and is very stable despite its high ground clearance. We hope to do very well in the figure-8 race.

Run Amok Web site

Builders: Mark Joerger, chronological age 48, but still immature — designer, mechanic, and driver and Aaron Max Joerger, just turned 10 — idea man and critic, Salem, OR

Robot experience: Run Amok was our first combat robot, although I've been building smaller, less aggressive robots for about 12 years.

Past robot competitions: none

Favorite movie or tv robot: Robbie the Robot, as he appeared in Forbidden Planet.

Occupations: Mark works as a researcher for the Oregon Department of Transportation; Aaron Max is a student in the 4th grade.

Hobbies: Mark performs as a magician at parties and events, and works very hard on his vintage British sports racer; Aaron Max loves video games and builds robots from plastic construction pieces.

Run Amok
Ask the Builders: Team Run Amok

What does it take to win Robotica? Champion Mark Joerger, builder of Run Amok has answered your emailed questions.

See his answers below.

Q: Congrats! Great job! Did you name your robot after the Daffy Duck cartoon?
A: In my mind the phrase "run amok" has always been associated with "robot." Whenever a robot appeared in a 1950s science fiction movie (I'm a big fan) you could bet that it was there to do one thing: run amok and try to kill its creator. Run Amok hasn't exactly tried to kill me (yet), but I do have a few scars.

Q: I'm 13 and I'm building a robot (really- I'm not just saying this). Where do you think I should get a motor at the local dump? Would a lawnmower motor work?
A: Your robot's motor will have to put up with a lot of stress, and scrimping by using a motor from the local dump is not recommended. I would suggest sticking with proven components for your first robot. You'll have plenty of opportunity to experiment in future designs.

Check the web sites of some of the successful robots of the general type you'd like to build to see what motors they use. Most builders will be happy to share this information with you. Motors from electric wheelchairs are currently a popular choice for heavy combat robots and they are very easy to work with.

Q: What was the most significant part of Run Amok's design that gave it the edge over the other competitors?
A: Colin Chapman was one of the great automotive designers of the 20th century. He had a one-word phrase that he liked to use to sum up his design philosophy: "Simplificate". Run Amok has a very simple yet elegant design. Thanks, Colin for the inspiration.

More specifically, I think there were two key design elements that lead to our success: the automotive-style steering and lots of ground clearance.

With only seven weeks available to build and test the robot, I knew I wasn't going to have a lot of time to practice operating skills. The automotive steering matched well with my R/C driving experience and felt very natural to me from the start. It is also much easier to make smooth turns around a track with steerable front wheels. This may be why no bulldozer has ever won the Indianapolis 500.

Run Amok's very large ground clearance (more than 4 inches) kept us from hanging up on the speed bumps in the Maze, and allowed us to fight our way free from debris in the Gauntlet. Run Amok was not the best robot at any single challenge at Robotica, but we were capable of completing all of them. We also had a great big double-scoop of luck!

Q: It was nice to see you and your son win. Did the motor look bad after everything was done? What kind of motor was it? I thought that it was great that you beat all the high tech robots...
A: My son and I had a really great time at Robotica, and I'd like to recommend robot building as a wonderful father/son (or father/daughter or mother/son or mother/daughter) activity.

The motor not only looked bad, it smelled bad! Run Amok is powered by a single Bosch GPA 750 motor running at 24 volts with a peak power output of about one and a half horsepower. At the end of the Gauntlet run in the finals, there was smoke pouring from the motor and it smelled like a burning pencil. All the effort of pushing at low speed and high loads had seriously heat damaged the coating on the wires in the armature. We had a spare, but after allowing it to cool down and giving it a load test, I decided that the damaged motor had a few more minutes of life left in it. We left it in for the Fight to the Finish rather than risk a mishap while replacing it.

Q: How did you come up with the idea to convert a gas engine riding lawnmower into an electricity- powered robot?
A: For the sake of simplicity and economy, I wanted to use a single motor to power Run Amok. In order to get good traction and a tight turning radius from a single-motor design, I needed some type of differential assembly for the drive axle. I went to a scrap yard for old lawn equipment looking for a chain-driven rear axle assembly. I found a 29-year-old riding lawn mower that had a perfect axle assembly. As I stood there looking at it, inspiration struck.

Here was a well proven chassis that had spent decades hauling somebody around a yard. It had perfectly workable steering and axle mounting systems were already attached. Certainly the heavy gauge-stamped steel would put up with the abuse of robotic combat, and there was plenty of room to mount the required batteries and electronic components once I removed the blade assembly, transmission, and engine. Even the wheels and tires would work. It was pure serendipity.

Q: How did you come up with your strategy in the final battle?
A: One of the classic problems in game theory is called "the three-way duel." The problem involves three marksmen two very good, and a third that is only so-so. It turns out that the so-so marksman has a very good chance of winning the shoot-out if he just bides his time and waits for the right moment to make his move. Run Amok was the so-so robot of the three in the final battle and, once it became apparent that I couldn't break into or influence the titanic struggle between JuggerBot and Ram Force, I retreated to wait for my "right moment".

Q: Congrats on a really fantastic victory. What are you going to do now? Are you going to build another robot?
A: Thank you!

Almost as soon as we returned from the Robotica competition, my son pointed out that he didn't think that it was fair that I got to have all the fun driving Run Amok. Fair is fair, but I really didn't want to turn a 10-year-old boy loose with 170 lbs. of high-powered steel and aluminum. Inspired by Jason Dante Bardis' "Mini Inferno" entry in Robotica, I set out to build "Mini Run Amok" for my boy: an operating 40% scale model of the full size beast. You can see some photos of "Mini" on my web site.

Other projects? Stay tuned.

Picture(s): Ed Carreon/DCI

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