Just because a bot is armored doesn't necessarily make it strong. You could make every armor panel out of titanium and still get demolished in one hit if you don't use a strong enough construction method. After all, titanium held together by Krazy Glue may not stand up well against a spinner. This is why usually bot builders pick different methods to construct a bot out of. These stronger methods give the bot more strength, which is good because it is sometimes said that no matter what the armor is, it is only as strong as the construction method allows it to be.

There are many different ways to build a bot, obviously. This is one of the attractive parts of the sport: there's plenty of room for experimentation. However, there are also some tried-and-true ways, a few of which I'll describe below.

First, there's angle-construction. What I mean by this is either taking an angle extrusion for the entire length of a side or cutting it into pieces called angle brackets for selective control of where everything is attached. Then whichever form of the angle is used will be welded (more details on that are below), drilled through and screwed together to armor panels, or drilled through and riveted through to armor panels. The result is a corner on the bot, where two armor planes join at a 90 degree angle. This makes it possible to create a boxy or rectangular shape, depending on how you lay it out.
One plus to using an extrusion for the entire side of a bot is that it makes the overall connection much more rigid and sturdy: it's harder to break an 8" long angle bracket than a 1" long! It also makes it look neater inside. However, it's obviously heavier and may take up internal space if space is at a premium. By the same token, the smaller angle brackets mean more efficient use of weight and internal space, but they aren't as firm, and when used in small numbers can actually be flexible (in my ant Superstition, I just epoxy the things down. I only use two per side, to the sides can rotate on me about the angle bracket connections. But the more brackets/secure points, the less flexibly (?) it will be held.
As for how the angle brackets/angle extrusion is/are held (I'm getting sick of this already), as I said the popular ways, especially with larger bots, are by welding, drilling and screwing together or drilling and riveting together. Welding is probably the most secure way to do this (I'll explain welding in more detail directly below), and is the lightest way since you aren't adding any weight, but is a fairly permanent connection, making repairs hard and also making it hard to impossible to use the same connection type for the entry-way to the bot. It's also a skill that can only be used if learned, otherwise should be sent to a professional, where costs can rise. Riveting together is also fairly permanent, and actually usually isn't as strong as screwing together would be. But on the plus side, it is quick and looks cool, and is a little lighter than using screws, I believe. Then screwing together can be heavier and sometimes requires adjustment in between battles, but is easily repairable and fairly strong. Overall, though, this method is probably both the simplest and the weakest.

Another method to constructing a bot is welding the armor together. Welding is basically getting metal so hot that it melts and joins with other metal that is touching is at the time. It is very strong (you're making the two pieces one, basically), and you have a little more freedom in shapes than in the prior method: you can weld armor into almost any shape you can put it in before welding. This makes things like triangles and wedges easier. There are some drawbacks, though. First off, welding is dangerous and requires skill and equipment. If you don't know how to weld and don't have any equipment, you may want to learn, but I recommend not for your first bot, unless you have plenty of time before needing to finish it. In the event that you still want it welded, you can have it professionally done. If it's professionally done, it will usually be very strong, but it can also be hard on the wallet. Be sure it's what you want! Also, when welding the entire bot together, it is usually impossible to get back in if you don't attach something differently than welding: as I said, welding is fairly permanent (if you don't want to cut in by plasma cutter or angle grinder at the last minute in a hurry, you ought to attach the top or bottom differently, e.g. by screws). This also makes repairs harder. But there is something cool about seeing a bot almost completely welded, as it looks almost like a one-piece bot. It's also lighter, there are little-to-no connection pieces like screws, washers or nuts. So it's not something to rule out by any means!

One philosophy, especially in weight classes that can spare the weight and need more support such as larger bots, is to support the armor with a kind of skeleton (endoskeleton, is that right?) to which everything is attached. This skeleton is generally just called a frame, and becomes very common as you move up through the weight classes. For this frame to work as planned, it should be rigid and strong, as well as well-designed. Everything tends to be attached to the frame, so it shouldn't be able to jiggle around, or splinter/break at an impact. And the attachment points will have to be pretty precise, as the armor panels will end up overlapping and if the frame is crooked the bot will be crooked if it even comes together at all. And reinforcements strengthen frames when necessary, so they should be placed in places where more impacts/stress is expected. But in combat, framed bots tend to be hard to destroy, as their innards are well-protected with the skeleton in place! The frames themselves are put together by welding, screws, rivets, and/or angle-brackets.
I actually have a little experience with this from our 12-lber last year: Ni was one of the few 12-lbers that I noticed had frames at our competition. I can vouch that it proved to be very strong, but also took up weight and was a lot of work. I didn't enjoy the extra time that it added, and if I had to do it over again would have encouraged using angles to hold the bot together.. but then again that might have failed in battle! We did fight some really destructive bots. The key with the frame is getting it right the first time, both in design and in drilling (if you plan to attach the armor to it by screws or rivets). This may require actualy building a prototype, which means more work, but is well worth it. After ironing out any problems, a well-made frame can actually make the armor attachment go more smoothly.
Most people who use frames tend to go by the welding route. After all, welded frames tend to be stronger and a little lighter. With Ni, we went the drilling route (mainly because we couldn't afford to weld it). We used screws and angle brackets to attach the frame to itself, and then used just screws through the frame to attach the armor (we used the same screws to hold the frame together as to hold the armor together usually, so this saved weight/time but made design harder). It was a lot of work, but it stood up to the second-place winner (I know, NI didn't, but its FRAME did)! There are drawbacks, but the advantages are great as well. Definitely keep the option open, at least.

Another method I've heard of, though rarely seen in person, is using a channel extrusion for two sides of the bot. This, if you recall, is similar to a C but with less curve (more like this: [ ). With this, the side is solid aluminum or steel, and also provides area on the top and bottom do directly screw, rivet or weld the top/bottom on, and maybe even angles facing forward and backward on the inside to attach front and back armor. Before starting to write this article I was going to make the point that this is a heavy idea, but just realized that you can probably just neglect the outer armor on those two channel-sides, as additional armor would be repetitive there anyway. That lack of side armor may actually improve the weight situation a bit. One advantage is that this is a fairly simple option, where parts of the connections are made easier by providing lip for the connections to be made. It's also strong, as this is a whole chunk of metal being used as a side, as well as to connect to. But it ain't perfect. First of all, the shape itself limits you: you need to find one that has a height between the two walls large enough to fit your innards into. If this even exists, it's going to be costly. Also, unless you modify the lips to make them thinner, the sides which provide connection points may also hinder your way into the bot, and it may be difficult to machine out holes for motors/axles for driving purposes. Still, upon further reflection, this isn't that bad of a choice. It's worth considering anyway, but make sure the advantages stack up better for you than the disadvantages, that is, make sure you can spare the cons and need the pros!

And finally, just because I just remembered it, you can follow Greg Ferree's example. Mr. Ferree built the champion Pain in the Butt (P.I.T.B.), which if I recall correctly has won every tournament it has entered. (Note: he's also an excellent driver, it's not all the bot design!) The main part of the bot is an aluminum block with holes machines out to exactly match the parts it contains within. The Ti wedges are added onto the block as extra bonuses (bonii?). Here are the pros and cons, as I see them.
Pros: Almost impenetrable. It's about as close to a "brick" bot as you can be without being completely literal.
Very few repairs. The thing is one piece after all!
Simple, once it's built, so little may go wrong.
Cons: Heavy, as it's solid aluminum!
Expensive: he probably had it professionally machined out of an Al block, and even if he did it himself, I doubt the Al block was that cheap.
Little reusability. Kinda hard to scrap parts from after you're through with the bot, eh?
Not too exciting to watch. Chances are you'll use most of the weight on the block, which means no surprising/doomsday weapons on it.

Now, are these the only construction methods out there? Of course not! People are still experimenting, and in the lower classes there are even stranger methods, since they can get away with more. (Soon, I shall build an ant held together completely by epoxy!!! MWAHAHAHAHA*coughcoughHACKKKKK*) These are just examples to get you to see some ways it is possible. Feel free to experiment from here! Remember, even failures are learning experiences (and moreso than successes, usually!).

So, that about concludes this page. Probably the best thing you can do from here is to check out some good build reports to see how people's bots are constructed! Here are a few links to check out:

Team Radicus (http://www.teamradicus.com/)
Team Radicus' website is run by Tony Hall, a man from Boston who has attends events all over the place (I met him at my rookie outing in Southern Assault; he was my pit neighbor that year). He now has a bot in almost every weight class, and keeps possibly the best build reports in the robotics community. Most can only strive to equal them. So if you're looking for examples of how bots are put together, this is a great place to start!

Team Nightmare (http://www.robotcombat.com/teamnightmare.html)
Jim Smentowski, builder of Nightmare, Backlash (and Shazbot & MicroNightmare for those of us in the ant class) runs this website, and has built many bots in his many years in the sports. In his robots section, he contains plenty of information on each bot. Exactly how much varies on the bot: some are just descriptions, some are detailed build reports and/or fight reports.. But it's worth some poking around for a different perspective.

Team Delta (http://www.teamdelta.com/)
Team Delta, builders of the famed War Machine and the almost-undefeated HAZARD have a good assortment of build reports in their robots section (called "status reports" here). Good reads.

Team K.I.S.S. (http://www.teamkiss.com/)
Team K.I.S.S. (derived from that brilliant saying, "Keep it Simple, Stupid!") is one of the oldest teams in the sport and usually have fun with everything. Their tips alone are worth a look, talking about what I have been talking about but with more math and cut right to the chase. (And it also lists the different colors of smoke which various ESCs give off when destroyed!) But mainly check through their section on S.L.A.M., their bot. Many pictures, may help some.


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