Scavenging Ready-Made Toys to Make Robots
Don't throw away that old toy - reuse it!
Ready-made toys are those that come pre-assembled, but that can be taken apart for useful parts. Good examples are Bio-Bugs (Wowwee), Furby (Tiger Electronics), and various motorized Tonka (and similar) tractors and trucks.
These and other toys like them can often be found on the clearance aisles, at garage sales, and even in thrift stores. At full price many of these toys don’t have enough useful parts in them to justify their cost, so always strive to purchase them used or at a discount.
Best Traits of Scavenged Toys
Here are the common elements of the ideal ready-made toy for scavenging:
- Is motorized, preferably with an electric motor. This category includes small “4WD” cars and trucks: they contain one motor that drives all four wheels at a time. You can readily adopt two of these toys for use in a traditional two-motor robot design. Just pop off the wheels on one side of the motor, and mount the two motor/wheel assembles onto your robot. Each motor/wheel assembly can be independently operated under electronic control.
- Uses a self-contained speed-reduction gearbox rather than gears mounted in the chassis of the toy. The latter is actually far more common, and not as useful, because you cannot readily repurpose the gearbox in your own creations. Self-contained gearboxes can be yanked out of the toy and implanted directly into your robots.
- If motorized, uses electronic control for the motors, rather than mechanical. With some of the Tonka and other tractor-type toys, the motors are controlled by operating levers, which are really mechanical links. To save costs, these toys use a single motor that is mechanically coupled to various wheels, treads, joints, and other articulations. You likely won’t be able to adapt these often-elaborate mechanical links in your robot without considerable effort, so it’s best to just concentrate on the parts you can readily pull out and reuse.
- Uses screws for assembly. This enables you to disassemble the toy by removing the screws. Toys that are made by gluing, hot-bonding (a kind of “spot welding” for plastic), or hydraulic press-on joints are harder to take apart.
Hacking Motorized Vehicles
While many toys simply beg to be yanked apart for their guts, others are useful in much of their original form as robot bases. Motorized radio control cars and treaded vehicles (e.g. Tonka or New Bright) are among the most common ready-made toys that are used “whole” as a robotic platform. The best such toys use a separate body and chassis; you can remove the body and use just the bare chassis. It’s easier to mount your robot parts to the chassis, and of course your robot looks less like a 1975 Le Mans (dark blue with white racing stripe) or yellow Caterpillar earthmover.
There are literally hundreds of motorized remote control cars and toy threaded vehicles, and not all toys are universally available to everyone, or would be considered inexpensive enough by all to hack. So, if you’re interested in using a motorized car or other vehicle as a robot base, know it’s a project that is best suited for those who enjoy experimentation and tinkering. Since the toy may be ruined in your hacking efforts (it happens to even the most seasoned robot builder), it’s best to use only toys purchased at a discount, either on clearance, at a thrift store or garage sale, or even pulled from your son’s closet of “forgotten stuff.”
Hacking Vs. Adapting
In this case, “hacking” is used in the good sense — take something, disassemble it, and turn it into something else. You’ve already seen how ready-made toys like treaded vehicles or remote control cars can be hacked apart to serve as robot bases, or general parts for your robots.
You don’t need to tear everything apart to use it. Sometimes, a quick-and-easy adaptation is all that is required. You need not disassemble the toy to make use of it. Case in point is the wireless remote-controlled sets from Rokenbok. These small vehicles are controlled via a centralized “radio tower” — you can operate up to four vehicles at the same time. Each vehicle is equipped with a receiver that operates at one of eight specific frequencies. You select the receiver, and therefore which vehicle, you want to operate on the hand-held controller.
The Rokenbok vehicles and other parts aren’t cheap; each vehicle costs from $50 to $90. At these prices, you probably don’t want to hack your Rokenbok toys for their motors, gears, and wheels. You can buy such parts for less. Rather, consider adapting the complete Rokenbok vehicles as robot bases. The body of most vehicles can be removed using a screwdriver. You can then mount your own robot body to the chassis.
Information about the internal architecture of the Rokenbok system is few and far between. With some work, the vehicles could be adapted to computerized control with any of the following:
- Hack the “Smart Port” on the Rokenbok radio tower (they call it the Control Center). So far, the company has not released details of this port, other than to say it is for future expansion.
- Communicate with the vehicles via the same radio frequencies and data format the Control Center uses. It’s a rather easy task to determine the operating frequency of the Control Center if you have access to an RF spectrum analyzer.
- Discard the control electronics in the Rokenbok vehicles, and connect a microcontroller and H-bridge directly to the motors. If you perform this surgery carefully, you could insert a switch or jumper block to allow you to switch between regular radio control mode and direct mode. That way your kids won’t yell at you when they’ve discovered you’ve hacked yet another one of their toys…