A: There's another post about 'Dead Metal's weapon down near the bottom of this page. The weapon was designed for cutting rather than blunt impact, and was used only after a competitor was already weakened and 'docile'. I don't believe that a similar weapon would be useable in open combat.

A: Sorry, no. I also don't know Philippa Forrester's phone number, Craig Charles' shoe size, or how many bolts held the Robot Wars arena together.

A: I make them better than graham crackers but not as good as a soup can. ABS plastic: far too thin, way too flexible.

A: There is plenty of information on both 'Ziggy' and 'Toro' in the archive, probably including the answer to whatever question it is that you're trying to ask. If you're asking about the gas they use to power their flippers: 'Toro' uses CO₂ and 'Ziggy' uses High Pressure Air (HPA) at around 3000 PSI.

A: - question #25.

Q: Do you know of a picture of British featherweight 'Eddie Evolution'?

A: 'Eddie Evolution' fought only once, in Robot Wars Extreme Series 2: Robot Rampage. It drove into The Pit and was never seen again. No photo available.

Q: Was 'Eddie Evolution' related to 'A-Kill'/'Saw Point 2'?

A: They looked a bit alike, but I don't know of any relation.

A: I guess somebody fixed the computer in my pants - I'm getting email from an ***hole again.

A: Probophobia was a wheeled robot, but it did have a pair of very long lifting arms sprouting from the sides of the machine that could rotate continuously in either direction. They could be used to drag/crawl forward in an emergency. These long lifting arms were able to get a grip on the edge of The Pit and lever Probophobia back onto the main arena surface during the Nickelodeon Robot Wars - the first and only time that a competitor escaped. Unfortunately, the rules say that once you're in The Pit you're out of the match - no reprieve possible.

A: I believe it was 'Hyperactive' in the second round of the Annihilator, but I'll have to check the tape to be sure. 'Cyclone' was the first spinner to throw an opponent out of the Robot Wars arena.

Q: I previously asked about Probophobia, thanks for the answers. Do you know which battle in Nickelodeon that it got out of the Pit?

A: I recall that it was in the 'Challenge Belt' competition against eventual champion 'TutTut'.

A: It's difficult to comment on a robot that only fought two matches and lost them both. Both 'Original Sin' and 'Original Sin 2' fought at RoboGames '07 - perhaps the team resources were stretched too thin to properly support both robots?

A: 'Panzer Mk 2' had a pneumatically adjustable front plow. It could raise or lower over about an 8" range. Although it could be used to provide a little 'boost' to an opponent, it was never intended to be an effective flipper.

A: Not sure what you mean by "same parts like the UK competitors." The loanerbots had square-tube steel chassis' and were powered by Bosch GPA 750 motors. These were common components used by the Robot Wars tech crew on the House Robots.

A: That either makes for a very tall 'bot or a very small blade, and I don't see what advantage you get by raising and lowering that blade. You could miss your opponent completely as they drive over. Better to put the blade somewhere where you can show aggression by pointing it at somebody and driving into them.

A: I'll assume the gearbox spins freely when the motor is removed? Possible problems:

• wrong pinion gear on new motor shaft;
• new motor shaft too long;
• improper motor mounting hardware interfering with gear rotation;
• foreign object fell into gearbox when replacing motor.

A: Ask them.

A: No, not true. Featherweight 'Pain in the Asp' is the product of Team Torque in the UK. I'm assuming that they are admirers of Team Plumb Crazy and 'Sewer Snake', so they built a featherweight version. Details of the 'bot are at the Team Torque website.

A: Mark J. here: the 'CKRC WIGGLE' is a re-branded Cirrus CS704MG Servo. I've used other Cirrus servos and found them to be reliable. I have not had 'hands on' this servo, so cannot compare it directly to the Hitec 645MG. The specifications look very good and the chatter on the web about them is good -- but I don't know any robot builders using them. YPYMYTYC.

You don't neen anything fancy to mount your lifter servo - a couple of blocks of UHMW polyethylene, polycarbonate, even wood will do nicely depending on your design. Spend that money on something more critical.

A: Traction in an antweight arena is an elusive goal. Dust, oil spray, and other contaminants on the arena floor will spoil traction for any set-up, so don't expect miracles. That said, a thin layer of RTV silicone rubber applied to the tread surface can give a significant traction boost under some circumstances.

Silicone is gooey stuff to work with, and you have to work quickly and with a steady hand to get a satifactory job. If you've never worked with silicone before, practice applying a thin layer to some scrap objects before setting to work on your tires. Silicone bonds better to some materials than others, and you may get some peeling in even the best cases.

Clean the tire surfaces very well with alcohol and let dry. Apply a very thin, even layer to the tread of each tire and set aside to cure for at least 24 hours before use.

A: Carefree Tires are made of centrifugally molded polyurethane foam which produces a lightweight, flatproof tire with a firm tread and flexible sidewalls. They take a great deal of abuse. We used them for front tires on heavyweight 'Run Away' in the second Robot Wars Extreme Warriors. Their downside is relatively poor traction compared to a conventional rubber tire of the same size. Some teams buff down the outer tread to get to a spongy layer with greater traction. I wouldn't call them 'perfect', but they do have their uses.

---

Q: a) What is the Potential Field Method and what is the inherent problem with it?

b) Would you say it is related to question 14 (in what way resp. why not)?

c) What is local minima? What can you do to avoid local minima? Explain

---

Q: Our Robocup robot can see in all directions and it is attracted to a red ball i.e. it drives to it. At the same time it is repelled from blue walls, i.e. when it comes too close to it, it moves backwards. Now assume the red ball lies in front of the blue wall. Describe the resulting behavior! Can you enhance on it? How?

A: Mark J. here: we get the same questions from this same engineering class every few months -- word-for-word. That proves that they at least teach engineers how to cut-and-paste.

We won't answer your homework questions for you, slacker. If you'd bothered to read the you would have found some of your answers.

A: There are many questions and answers about spring powered weapons in the archive. Quite a few builders have tried them, but only one has been really successful. Pneumatics are a simpler, more powerful, and more popular solution.

Q: [Chinese Forum] Aaron, in your last question you said that there was only one bot using spring loaded system really succeeded - which is that one? I guess Derek Young's 'Son Of Smashy', wasn't that? Could you analyze why had SOS been that successful?

A: Yes, but no points for correct answers to your own questions ; ^ ) Derek's success with 'Son of Smashy' had less to do with the spring power than it did with being the first powerful overhead axe middleweight to turn up at BattleBots (Long Beach, 1999). The judges were impressed by Derek's aggression and ability to do some damage. When overhead axes became less of a novelty you needed more than spring power to impress the judges and pneumatic power took over.

A: 'Gilbert' is very quick, but I'm not sure how fast. MH Robotics does not share much info on their robots - I don't know what motors 'Gilbert' currently uses.

A: Mark J. here: neither Mechanum wheels nor omniwheels are known for a lot of traction, and neither design has an apparent theoretical advantage. The Fingertech Mechanum wheels have actual rubber rollers instead of the hard urethane rollers commonly found in omniwheels, so I'd give them a potential traction advantage. Clean the rollers before every match!

A: Mark J. here: 'Maximus'? Good heavens, no! I have photos of robots with hinged wedges dating back at least as far as the 1996 Robot Wars event. That's five years before 'Maximus' fought.

Q: Did Kevin Barker's 'Death By Translation' used Melty Brain system? And how could DBT spins at 1000rpm by only using one wheel?

A: Yes. 'Melty Brain' refers to any system that controls directional motion (translation) on a thwackbot by rapidly changing motor power as the robot spins. 'Death by Translation' uses Rich Olson's custom electronics to measure rotational speed with an accelerometer and pass that information on to a micro controller to do the power changes.

The physics of spinning with a single tangential wheel are difficult to describe. It's a bit like a spinning cowboy lariat - it's only supported on one side, but spinning forces keep it relatively stable. The single-wheel configuration does cause some problems; directional control is not good at higher speeds. It's an interesting experiment, but it has achieved no combat success to date.

A: Mark J. here: you've been thinking pretty hard about this. The short answer is 'yes', but there are problems in implementing such a design.

• The kinetic energy of a rotating object depends on mass, speed, and the shape of the object. The amount of KE lost from the blade would depend on where the mass was removed as well as how much mass was removed. The kinetic energy of the added flywheel is also dependent on it's shape as well as it's mass. The Team Run Amok Spinner Spreadsheet will help you calculate the rotational inertia of the blade and the proposed flywheel.

• The energy stored in the added flywheel would need to be transmitted thru the gearing system to the blade at the instant of impact. That will place a great deal of extra stress on the gearing system. If a belt-drive is being used, the stored energy from the flywheel could be lost to slippage. If a chain or gear system is used, you risk breaking the drive. The added weight needed to reinforce the weapon drive could cost more weight than you'll save.

A: I don't think you actually need an email at your school to download. Very few sub-college students will have one. Go to the Autodesk Education Community website, register with your regular email address, and see what happens.

A: Bill Nye is great at what he does. I didn't think he was a good match for BattleBots.

A: I get it -- if you have a dustpan under your opponent you can strike downward without flipping your own robot upward. Not bad, but a downward striking rotary blade will also strike 'inward', jamming the blade and your opponent into the dustpan and against your own 'bot. You are correct that there would be large forces applied to your own robot structure as well.

Q: how about a four sided wedge with a blade in the center? so if you go up any side, you get shreded. Kind of like an arena hazard on wheels.

A: Relying on an opponent's actions to cause their own damage is not a winning strategy. You're also in real trouble if your opponent can get under your wedge - how do you apply your weapon then? Better to put your weapon in a position where you have direct control of its application.

I'm not trying to shoot down your ideas, but a good number of very creative builders have been thinking and experimenting with combat robot design for 15 years now. I'm convinced that every design that you or I can come up with has already been considered and possibly built by some competitor by now. The time for big new designs in combat robots is long past. Successful combat robots are based on quality design and construction.

Q: Also, (sorry if I'm bugging you) was the lightweight bot "crusher" from the same team that built bad Attitude?

A: Yes, Team Attitude and Thomas Petruccelli fought with lightweight 'Crusher' at BB 2.0 and BB 4.0.

Q: And since Bad Attitude is now "Nasty Attitude" would that raise the value of a "Bad Attitude" toy?

A: No.

Q: And, whats your opinion on bad attidude? I thought that he was pretty cool.

A: Nice robot. Well designed, well built, and well driven.

A: Two problems:

• When an impact spinner hits, there is enormous force placed on the weapon mount. Putting all that force out at the end of a lifting arm is going to give that force a lever to help it tear apart your lifter mounts. Robot Wars housebot 'Dead Metal' had a spinning blade mounted on a four-bar aparatus, but the circular blade had very small teeth designed for cutting -- not for impact.

• I'm not a fan of multi-weapon designs. Each of the weapons will have less weight allowance and therefore less power. If your spinning bar is strong enough, you won't need to do any flipping and vice-versa. There have been plenty of multi-weapon robots, but no champions.

A: No, but I know how this rumor started. Run Amok used the main chassis elements from an old riding lawnmower that we salvaged from a junkyard. Some photos on the Run Amok Origins web page show the lawn mower with the original mowing blade still in place. The blade assembly was removed in stripping down the chassis, but the photo seems to have caused some confusion.