An experimental robot can cost anywhere from nothing to well over $100,000.
Mark Tilden, the creator of the BEAM (Biology Electronics Aesthetics Me-chanics) robots, can build a walking bot out of an old discarded Walkman radio in one evening without spending a single penny. A simple microcontroller-driven tabletop line, following robot will cost about $200, and a top competitor BattleBotcan easily exceed $20,000.
Building a combat robot is not a cheap venture, and you should be prepared to spend a lot of money to build something competitive. Most builders spend several thousand dollars building their bots. You might be the lucky individual with a home machine shop (or have a friend with one) and an uncle who owns a junkyard and a surplus store. However, most of us aren’t this fortunate and must hunt through countless stores and catalogs to find what we want. Appendixes A-C at the end of this book will lead you to many proven sources of robot parts. No mat-ter how full your junk boxes may be, you’ll probably find yourself purchasing a lot of the parts to build the robot—especially the electronics and controls.
S afety
Before you start building your bot, you must also address safety issues. If you’ve watchedBattleBots, chances are you’ve heard the announcers stressing the use of safety glasses and proper supervision. As adults, most of us have already learned the basics in shop safety. But the construction of combat robots extends way be-yond what is normally considered a hazard in a home shop, and severe injuries are possible with even the smallest combat robot—both in operation and in the con-struction process.
Before we delve into safety issues, we should mention gaining knowledge in the use of shop tools. All the safety equipment in the world won’t protect you from unsafe shop practices. If you haven’t been instructed in the use of shop tools through a shop class at school, or through instruction at your job, you should con-sult a friend or acquaintance to instruct you, or leave the work to those who know how to do it safely. This cannot be stated strongly enough!
A chuck key left in a drill press when it is turned can be thrown at high speed right through safety glasses. A slight slip with a band saw can turn you into a nine-fingered bot builder in a fraction of a second. Misuse of a bench grinder can cause a grinding wheel to literally explode into shrapnel, riddling your body, face, and eyes with hundreds of rock-shaped bullets. A loose piece of clothing can be sucked into a metal lathe in a second, and you along with it. If this scares you, then we authors have done our job here. You’re welcome.
Safety glasses are a must when using any power tool for any purpose. Even the tiniest particle in your eye can ruin your day, and a metal particle traveling at high speed can destroy your eye or eyes. Buy and wear the good, tempered glass kind with side shields. Keep those glasses on even when working with batteries and with high-amperage cables. A sealed electrolyte battery when dropped on a floor can crack and splash acid everywhere. Sparking cables can make you feel as if you placed your face on a welding table.
Okay, enough said on these issues.
Safety in the Use of Shop Tools
There are many power tools available to the robot experimenter. One of the first items you should purchase outside of handheld tools is a bench drill press. In itself, this is not a dangerous tool, but it can still cause injuries. The belts and pulleys at the top, if left exposed, can cause injuries to the hands. The drill chuck generally runs at a low enough speed when drilling to not cause flying bits of metal, but the use of other metal-cutting tools can cause metal to fly everywhere. Again: use safety glasses. Tighten the bit or tool securely and then remove the chuck key. Feed the tool or bit into metal slowly, using a lubricant, and using a lower speed for larger drill bits. Be sure to have the work piece securely clamped to the drill press table to prevent it from rotating.
Many of the same safety tips apply to all power tools when working with metal.
Be careful of the placement of your hand when using your other hand to hold a workpiece. Bench grinders, metal and wood band saws, routers, and saws all require you use common sense when operating. Most hand-power tools have an internal blower to cool the motor, and this wind can sometimes blow chips and dust into your eyes. Always have a complete first aid kit on hand and know how to use it.
The larger shop tools such as metal lathes, milling machines, and the various types of welders all require special knowledge that cannot be obtained from any
“manual,” and it is recommended that you obtain special instruction in their use.
Community colleges usually have shop courses, and even a local machinist can give you help in this area.
Safety with Your Robot
Safety is also critical when dealing with your bot. This should come as no surprise, because often these machines are 350 lb. warriors designed to obliterate other ma-chines their own size. You can just imagine what a bot like this can do to the tender skin of a human being. Be extremely careful when you power up your machine for testing. Always remember Murphy’s Law: “If something can go wrong, it will.”
Always assume that any part of your bot will fly off at any time, and plan accordingly.
Never, ever operate a combat robot in the presence of children.Even a seemingly benign machine such as a wedge can go out of control and quickly smash into someone, breaking legs or doing even worse damage.
No amount of body armor and safety glasses can protect a person from a large spike that is accidentally thrown from a spinning robot. A pneumatic weapon arm can accidentally deploy upward and sever a person’s head. Sharpened weapon edges can still cut you severely, even when you’re not in the middle of operating your machine. A 1,500-psi gas line can break away and whip about like a mad cobra.
The use of a full-face mask is recommended when dealing with high-pressure pneumatic systems.
There are many more ways to be injured while building and operating a combat robot—far too many to list. The authors and publisher of this book cannot take responsibility for injuries sustained during any construction, testing, or use of the bot. Use common sense, then plan, and then work carefully and slowly. Watch out for others. When working on your bot, make sure the batteries are disconnected.
And above all, never leave a functional bot unattended. If you follow these simple safety suggestions, you should not be injured. Save the “hurting” for an oppo-nent’s bot in a combat contest!