Questions and Answers from the TLC/Discovery network Robotica Fansite.

Run Amok Combat Robotics
Q & A from the TLC/Discovery Robotica Fansite
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During the three seasons of Robotica on The Learning Channel the TLC/Discovery website invited viewers to submit questions to be answered on the site. Different sets of questions were answered sequentially by:

  • Jump To Season 1 Finalist Jeff Cesnik of Team Kritical Mass
  • Jump To Season 1 Champion Mark Joerger of Team Run Amok
  • Jump To Season 2 and 3 Host/Advisor Dan Danknick

Jeff Cesnik

Ask the Builders

What's it like to compete in Robotica?

Finalist Jeff Cesnik, builder of Kritical Mass has answered your emailed questions.

Q: Where would somebody interested in this sort of thing learn more and start building?
A: There are many resources on the web devoted to combat robots, full of tips and information — I would recommend reading as much as you can about what's involved and just how expensive it is to build one of these things. Be prepared to give up your normal life (sleep, jobs, friends, wife, girlfriend, etc.) while you build your new creation. And if you're lucky enough to have a friend who's a machinist and who wants to get involved, that's great — but he will need to be bribed often, as he does this stuff for a living.

Here are some good places to start:

Society of Robotic Combat
Dangerous Machines
Robotic Combat Tips
Cool Robots
Team Delta Battle Robots

Q: What kind of servos or remote do you use to control your robot?
A: We use a Futaba 8-channel computerized radio to control Kritical Mass. Main drive and blade power are provided by three heavily modified 24-volt Sullivan model airplane starter motors. We use a Vantec RDFR38E speed controller to control the power to the main drive, and a Victor 883 speed controller to control power to the "Blade o' Death."

Q: Do you think I can build a robot out of an old remote control car? (By the way I'm 12 and I'm top in science and I'm a good engineer and inventor!)
A: Sure! For your first robot, you could start out with an R/C car — that way the hard part is already done for you (the drivetrain) and you can concentrate on weaponry and other things. I think that would be a great way for someone to get started and learn more about how to engineer something as complex as a battle robot — the more experience you gain, the better off you'll be when you decide to build bigger ones for competitions.

Q: What inspired you to build this configuration? What is the ground clearance of Kritical Mass?
A: When we first started building Kritical Mass, we took into consideration all of the different challenges that make up Robotica. We studied the blueprints of the Robotica set over and over again and scrutinized every aspect of our design along the way. What we wound up with when the dust cleared was a machine that we felt would handle all of the challenges of Robotica and then some. While the mechanical "guts" of the robot were well thought out, we honestly had no idea what it was going to look like until the very end. Kritical Mass's ground clearance is about an inch and a half — and yes, we were definitely worried about those speed bumps!

Q: Were did you get your parts for Kritical Mass?
A: We made a lot of the custom parts for Kritical Mass (motor mounts, bearing mounts, pillow blocks, wheel hubs, etc.) ourselves out of raw aluminum and steel on a Sherline CNC mill and lathe — these are great little machines. The parts that were too big for our machines (such as the blade) we had a local machine shop make for us. Most of the off-the-shelf mechanical parts for Kritical Mass (such as sprockets, chains, bearings, wheels, etc.) came from industrial supply catalogs. Raw materials (about 50 feet of tubular steel and a lot of aluminum) came from local metal suppliers. Wire, fuses, holders, and terminal ends came from local car stereo installation shops. Our radio and speed controllers are from Futaba, Vantec, and IFI Robotics. Our motors are heavily modified model airplane starter motors from Sullivan Products. We found our ramming spike lying around in a machine shop — it used to be one of the bits for a machine that grinds up asphalt roads. And last but not least, a friend gave us our armor plate for Kritical Mass's "skin" — it was just sitting around in a barn collecting rust.

Q: Who has been your hardest opponent so far in Robotica?
A: Our hardest opponent in Robotica was Run Amok (in the Championships, to air this Wednesday). Stay tuned and you'll see why...

Q: I would like to know what age you started building robots?
A: I started building simple robots when I was about 11 years old, but nothing at all like what we're building now.

Q: How did you practice the maneuvers for Robotica's challenges? Did you use anything to simulate another robot for practice?
A: We really did not have a lot of time to practice driving before Kritical Mass had to be shipped out to California, so we mostly just drove it around to make sure nothing was going to break and that the robot would handle well. The practice sessions did come in handy, as we were able to identify a few handling problems and were able to correct them before the competition. Most of our driving practice took place on the streets in my neighborhood, and we didn't use anything to simulate another robot.

Q: Do you have any strategies that you are going to try in the Championship?
A: The only thing we were really worried about in the Championship was the Gauntlet— this was our weakest event. If we would have had the time, we would have liked to fit some sort of plow to keep debris out from under Kritical Mass. Our strategy will be to take it a bit slower this time, and try not to get hung up on anything.

Q: How much did you spend on your creation?
A: I still haven't added up everything we spent on Kritical Mass, but a good guess is about $4,000.00 in materials and radio equipment (things like steel, aluminum, wheels, bearings, motors, chains, sprockets, radio equipment, speed controllers, miscellaneous odds and ends, etc.), and about another $3,500.00 in tooling to make specialized parts (welder, steel cutoff saw, Sherline miniature lathe and mill, etc.). Building a competitive robot can get very expensive.

Mark Joerger

Ask the Builders

What does it take to win Robotica?

Champion Mark Joerger, builder of Run Amok has answered your emailed questions.

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 motor, 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.

Dan Danknick

Ask Dan Danknick

Robotica host and technical advisor, Dan Danknick, has answered your questions about robotic competition.

Q: I would like to get my grandson involved in this sport. Now he's very young...where should I start? Where do I get information or some kind of kit to get us started.

- John

A: Hi John, laying a technical foundation early in your grandson really helps set him up for future endeavors, whether they are building bridges or robots. I will recommend two things for your him. First, a set of LEGO Mindstorms. The kit is expandable to the point that even the pro builders have LEGO based competitions every so often! Second, have a visit to for some very interesting and inexpensive kits— my favorite is the 5-axis arm.

Q: I was watching your show the other day, and I saw the mice attack the competitors. I was wondering if the mice were controlled by people, or if they acted on their own accord. They were my favorite and I thought maybe I could drive them some time.

- Jace

A: Most of the technical details concerning the Robotica Rats are classified but I can tell you there is an experienced Hollywood SFX (special effects) team in control of them. Pay close attention to their behavior — not only do they impede and attack the competitors at times but they can also give them a hand in the Labyrinth!

Q: Which robot is your favorite in this year's Robotica?

- Chris

A: I think a better question is: "What is my favorite technology in this season of Robotica?" It is undoubtedly the varied approaches to building reliable tracked robots. I tried to show the very cool engineering in Botzilla's suspension and always wished the show was two hours long so I could talk even more about all of the challenges involved. A strong second place goes to Flexy Flyer's adaptive body design that incorporates some of the advantages of tracks without the liabilities of keeping the tracks on the drive sprockets.

Q: I see that Robotica will be letting a 15-year-old genius on the show on Wednesday, January 16. I was just wondering how old you had to be to enter the competition. My friend and I (both fourteen years of age) would like to be on your show next year.

- Brock

A: David Roy brought an amazing robot, Thor, to the show and I was very impressed with his technical skill as well as his ability to recover from the calamity of losing his flipper arm. Most people only think about the design work that precedes the competition, but how you react to the dynamics of what happens in the Gauntlet and Labyrinth are even harder! If you and your friend have what it takes, fill out an entry from and see if you can get on the show!

Q: Could you ever make the perfect robot for Robotica? Can you possibly please the Gauntlet, the Maze, and the Fight to the Finish, all in one robot?

- Hall

A: There is no question that Robotica is an event designed for the thinking man. Mike Konshak (Flexy Flyer) told me he watched all of the Robotica season one videos before designing his robot to take on the challenges of season two. Analysis of other robot failures led him to a modular design that could change slightly for each of the challenges. Flexy's appearance for the Fight to the Finish was most noticeable: the body segments were locked, the big tires were replaced with smaller more tractive ones and hinged ramps (the "cow catchers") were added. And you saw how that fared against Scarab!

Q: When they are competing in the Labyrinth how hard is it to break the glass panes?
A: It was shocking to all of us how hard that glass was to break! You can see the strips flex dramatically at times without shattering but once the robot was able to get a good nick on an edge — pow, it would just explode. The tiny bits turned out to be an unexpected hazard for the competitors, as one tiny piece disabled Botzilla's pneumatic control system for his arm. Glass is an amorphous solid, which means the molecules are unordered and it doesn't have a crystalline structure. It is not a liquid that flows very slowly — that is a scientific "urban legend."

Q: My dad and I are building a robot from scratch and we were wondering what would be the best batteries to put in our robot— keeping a realistic budget in mind?

- Sam

A: The easiest and cheapest batteries to get started with are called gel cells, or sealed lead acid batteries. You can buy them at most hobby stores as they are used in R/C airplane "field boxes" to run the starter motors on gasoline engines. They are not exactly high performance but they are plentiful and inexpensive. And they are pretty safe as the interior electrolyte is immobilized as a gel so if something goes wrong and the case cracks, acid won't splash on anyone. I recommend you avoid motorcycle and car batteries as they DO have liquid acid inside and can be dangerous to experiment with.

Q: What is the highest horsepower motor (I assume Robotica candidates cannot use internal combustion engines) a Robotica candidate can utilize?

- Richard

A: We spent a lot of time trying to show viewers that you don't need a hammer to swat a fly — but you do need finesse and a well-designed fly swatter! Whyatica and InTriVerter had the most powerful motors in season two. Each motor could develop 15 horsepower peak (that's enough power to light up 112 light bulbs in your house). But the real problem with high power motors are the subsystems to support them grow as well. Power controllers for big motors are expensive and you end up carrying a ton of batteries, which is a problem when that maximum weight is only 210 lb. for a qualifying entry. On the other hand, Ill-Tempered Mutt only used two motors and it did very well.

Q: I am doing a speech about robots and the robot shows on TV, but my research indicates that the robots on the shows are more of a remote control vehicle rather than a true robot. What do you think?

- Zac, age 12

A: This is a good question that I've heard discussed many times. I think the problem arises in that most people have decided the word robot means some autonomous machine attempting to accomplish a goal without human interaction. explains that the word "robot" comes from the Czech word "robota" meaning servitude or forced labor. A radio-controlled machine fits this definition perfectly! Isaac Asimov wrote the classic stories in I, Robot back in the early 1940s and discussed complex machines with such high reasoning that they kept getting into trouble. From what I've seen of advanced learning machines that my associates are testing, we have a long way to go before C3PO becomes a reality.

Q: My friend and I want to build a robot for Robotica. Could you please tell me the size and weight limits?

- Heather

A: For the review of competitors the rules are published online at Note that they may change for the next Robotica event, so try to engineer a design that can adapt!

More Robotica: Robotica Journal -- Run Amok FAQ -- The "Robot Riots" Interview

Run Amok Combat Robotics homepage