Servo - March 2008

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Robot Kits for

Easier Robotics

Ivividly remember the excitement of building my first electronics kit. Okay, so the kit was an old surplus reject that used vacuum tubes instead of transistors. But to an 11-year-old interested in the science of electronics, all that mattered was the scores of tiny parts packed into individual numbered plastic baggies, and the smell of smoldering solder as I methodically attached one wire to the next.

The thing didn’t work when I first turned it on — in fact, sparks flew and it tripped the circuit breaker when I flicked the switch. But all was well after my dad looked over my handiwork, re-soldered some cold joints, and corrected the connections I had wrong. For years after, I enjoyed listening to my phonograph player through the three-tube amplifier that I built.

Kits are ideal for those wanting to build things but that aren’t too keen on having to round up all the parts beforehand. Just like with electronics, robot kits help you make your own bot, saving you lots of time — and even money. Unless you have parts left over from a previous project, it’s usually cheaper to build a robot from a pre-packaged kit, because you don’t have to buy all the bits and pieces from several different sources, saving your gasoline bill and shipping costs.

In this installment of Robotics Resources, we’ll cover a selection of robotics kits and kit sources. There are dozens and dozens of robot kits, and hundreds of online retailers selling them, so there’s no way we can cover them all. But the assortment described here should give you a good idea of what’s available, and where you can get it.

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All-in-One or Base Kits

Not all robotic kits are wholly self-contained, providing absolutely everything you need to build your first (or second or third or ...) robot. Some are all-inclusive, such as the Parallax BOE-Bot, which includes the hardware, software, and computer programming essentials to construct a functioning autonomous vehicle. These kits serve as an excellent introduction to robotics, and are particularly well suited for those just starting out.

Then there are the base kits, such as those from Zagros Robotics or my own small manufacturing company, Budget Robotics. These provide the hardware — the mechanicals including chassis, frame, wheels, and usually motors — but not the electronics. You are expected to add those yourself. This approach to robotic kits allows you to reuse your favorite microcontroller or other electronics, or mix-and-match components so you get exactly what you need. These kinds of kits generally require a little more experience, but offer the flexibility of selecting just the components you want to use.

Too, there are variations within the theme of the all-in-one kit and the base kit. Modular kits such as the SuperDroid Robots Trekker line offer a means to customize elements, including drive components and sensors. The modular components let you add custom features if and when you want them — a sort of attachments system for desktop robotics.

Construction set kits, which include the Lynxmotion Servo Erector Set, the Robotis Bioloid, LEGO Mindstorms, and the Vex from Vex Robotics, are

comprised of multiple interchangeable building parts. The parts are designed around a common set of motors and other electronics. With a different arrangement of components, you can build two-, four-, or six-legged walking robots, robots that run on two or more wheels, or tracked tank-like robots.

On the other end of the spectrum are base components, which you then use to build a robot of your own design. The base components are pre-cut and pre-drilled, saving you the labor of shaping these parts in your garage. For example, if you’re building a small desktop robot, you can find pre-cut discs and other base parts made of metal, plastic, and even wood. Added to the base might be motor mounts and stand-offs to construct a multi-tiered chassis. You are expected to supply the motors, wheels, battery and holder, microcontroller, and other parts to complete the system.

Across the spectrum of kit types, nearly all allow some form of modification and customization. Modular designs work best with components made for them, and you’ll get the most profession-al-looking results if you use components specifically designed for the robot. Even so, in nearly all kits you can fashion your own solutions, and attach them to your creation using small nuts, bolts, hook and loop fasteners or sticky-back tape. Bases made of wood or plastic are easier to rework using ordinary shop tools.