Robotica - Ask the Builders -- The Learning Channel = (TLC) -- Robot Competition

Ask the = Builders

What does it take to win Robotica? Champion = Mark=20 Joerger, builder of Run=20 Amok has answered your emailed questions.=20

See his answers below.

Q: Congrats! = Great job!=20 Did you name your robot after the Daffy Duck = cartoon?

A:=20 In my mind the phrase "run amok" has always been = associated=20 with "robot." Whenever a robot appeared in a 1950s = science=20 fiction movie (I'm a big fan) you could bet that it = was there=20 to do one thing: run amok and try to kill its creator. = Run=20 Amok hasn't exactly tried to kill me (yet), but I do = have a=20 few scars.

Q: I'm 13 and = I'm=20 building a robot (really- I'm not just saying this). = Where do=20 you think I should get a motor =97 at the local dump? = Would a=20 lawnmower motor work?

A:=20 Your robot's motor will have to put up with a lot of = stress,=20 and scrimping by using a motor from the local dump is = not=20 recommended. I would suggest sticking with proven = components=20 for your first robot. You'll have plenty of = opportunity to=20 experiment in future designs.=20

Check the web sites of some of the successful = robots of the=20 general type you'd like to build to see what motors = they use.=20 Most builders will be happy to share this information = with=20 you. Motors from electric wheelchairs are currently a = popular=20 choice for heavy combat robots and they are very easy = to work=20 with.

Q: What was the = most=20 significant part of Run Amok's design that gave it the = edge=20 over the other competitors?

A:=20 Colin Chapman was one of the great automotive = designers of the=20 20th century. He had a one-word phrase that he liked = to use to=20 sum up his design philosophy: "Simplificate". Run Amok = has a=20 very simple yet elegant design. Thanks, Colin =97 for = the=20 inspiration.=20

More specifically, I think there were two key = design=20 elements that lead to our success: the = automotive-style=20 steering and lots of ground clearance.=20

With only seven weeks available to build and test = the=20 robot, I knew I wasn't going to have a lot of time to = practice=20 operating skills. The automotive steering matched well = with my=20 R/C driving experience and felt very natural to me = from the=20 start. It is also much easier to make smooth turns = around a=20 track with steerable front wheels. This may be why no=20 bulldozer has ever won the Indianapolis 500.=20

Run Amok's very large ground clearance (more than 4 = inches)=20 kept us from hanging up on the speed bumps in the = Maze, and=20 allowed us to fight our way free from debris in the = Gauntlet.=20 Run Amok was not the best robot at any single = challenge at=20 Robotica, but we were capable of completing all = of=20 them. We also had a great big double-scoop of = luck!

Q: It was nice = to see you=20 and your son win. Did the motor look bad after = everything was=20 done? What kind of motor was it? I thought that it was = great=20 that you beat all the high tech robots...

A:=20 My son and I had a really great time at = Robotica, and=20 I'd like to recommend robot building as a wonderful = father/son=20 (or father/daughter or mother/son or mother/daughter)=20 activity.=20

The motor not only looked bad, it smelled bad! Run = Amok is=20 powered by a single Bosch GPA 750 motor running at 24 = volts=20 with a peak power output of about one and a half = horsepower.=20 At the end of the Gauntlet run in the finals, there = was smoke=20 pouring from the motor and it smelled like a burning = pencil.=20 All the effort of pushing at low speed and high loads = had=20 seriously heat damaged the coating on the wires in the = armature. We had a spare, but after allowing it to = cool down=20 and giving it a load test, I decided that the damaged = motor=20 had a few more minutes of life left in it. We left it = in for=20 the Fight to the Finish rather than risk a mishap = while=20 replacing it.

Q: How did you = come up=20 with the idea to convert a gas engine riding lawnmower = into an=20 electricity- powered robot?

A:=20 For the sake of simplicity and economy, I wanted to = use a=20 single motor to power Run Amok. In order to get good = traction=20 and a tight turning radius from a single-motor design, = I=20 needed some type of differential assembly for the = drive axle.=20 I went to a scrap yard for old lawn equipment looking = for a=20 chain-driven rear axle assembly. I found a 29-year-old = riding=20 lawn mower that had a perfect axle assembly. As I = stood there=20 looking at it, inspiration struck.=20

Here was a well proven chassis that had spent = decades=20 hauling somebody around a yard. It had perfectly = workable=20 steering and axle mounting systems were already = attached.=20 Certainly the heavy gauge-stamped steel would put up = with the=20 abuse of robotic combat, and there was plenty of room = to mount=20 the required batteries and electronic components once = I=20 removed the blade assembly, transmission, and engine. = Even the=20 wheels and tires would work. It was pure = serendipity.

Q: How did you = come up=20 with your strategy in the final battle?

A:=20 One of the classic problems in game theory is called = "the=20 three-way duel." The problem involves three marksmen = =97 two=20 very good, and a third that is only so-so. It turns = out that=20 the so-so marksman has a very good chance of winning = the=20 shoot-out if he just bides his time and waits for the = right=20 moment to make his move. Run Amok was the so-so robot = of the=20 three in the final battle and, once it became apparent = that I=20 couldn't break into or influence the titanic struggle = between=20 JuggerBot and Ram Force, I retreated to wait for my = "right=20 moment".

Q: Congrats on = a really=20 fantastic victory. What are you going to do now? Are = you going=20 to build another robot?

A:=20 Thank you!=20

Almost as soon as we returned from the = Robotica=20 competition, my son pointed out that he didn't think = that it=20 was fair that I got to have all the fun driving Run = Amok. Fair=20 is fair, but I really didn't want to turn a = 10-year-old boy=20 loose with 170 lbs. of high-powered steel and = aluminum.=20 Inspired by Jason Dante Bardis' "Mini Inferno" entry = in=20 Robotica, I set out to build "Mini Run Amok" = for my=20 boy: an operating 40% scale model of the full size = beast. You=20 can see some photos of "Mini" on my web=20 site.=20

Other projects? Stay tuned.