Early BEST Robotics Kit
The first few years, the “kit” was whatever Ted and Steve (our founders) could wrestle up from the dumpsters and salvage yards. The control system was an Model Airplane Remote Control (RC) system, modified to use ground frequencies of course to be FCC compliant. Everything else was raw materials or bits and pieces of unique items Ted and Steve got their hands on. They quickly realized that they needed to separate the RC equipment, which was reusable (and a little expensive), into a separate container and ask that teams return it at the conclusion of the contest (hence the name Returnables Kit). The other “stuff” was expendable or consumable by the teams so they began calling it the Consumables Kit.
Many teams today probably don’t realize that the early Control System (i.e., Returnable Kit) did not have any programmable elements. There was no microcontroller to “program”. There was no “code” to be written. Everything worked just like a RC model airplane. A handheld transmitter with two joysticks is all the control that existed. There were no extra buttons like on your fancy XBOX-like controllers that came later. All motions of the robot were controlled directly with these 2 joysticks; 4 motions, up-down-left-right. That’s it. Motors and servos were controlled directly by one of these 4 motions.
An RC receiver module was placed on the robot and it received the Radio Frequency (RF) signals from the transmitter whenever a “stick” was moved. Each transmitter/receiver pair had matching frequencies so they could communicate. Although the receiver supported up to 7 channels, only 4 channels were used. Each team got their own transmitter/receiver with a unique frequency so that their robots could operate without interfering with one another, just like model airplanes can. There were a couple of different RC systems used in the early years but BEST settled into the Futaba 4VF controller, and later the 4YF.
Servo motors (just like those used in model airplanes) could be plugged directly into the RC receiver on the robot. But the bigger drive motors had to be hardwired directly to battery power using something called the Switch-Fuse assembly. This was simply a wiring harness created by Steve and Ted that consisted of a modified Y-connector harness, a household light switch and an automotive fuse holder (with fuse). This gave the robot an on-off switch for the motors so they could actually stop motion by killing power in the case of an emergency. Two white molex connectors connected to other mating connectors with leads that were soldered directly to the motor terminals.
To reverse the direction of a motor, you had to actually implement something on the robot that would reverse the voltage to the motors. Ted invented this simple method using a servo and documented it in one of his famous Ted-CAD (hand) drawings.
Here is an example actual implementation of all of this crazy wiring.
Electronic Speed Controllers
Soon, Steve and Ted learned of a nifty electronic device used in RC model aircraft called an Electronic Speed Controller (ESC). This great device could variably control the voltage to the high current motors and thus control the speed of the robot. The ESC “speed” (or voltage output) could be controlled through the pulse-width-modulation signal from the receiver, much like a servo motor was. The HiTec SP-520 was the first “motor speed controller” to be used in the BEST Kit; but only 2 were included (to the kit which had 4 moors). The SP-520 required some manual adjustments to set the neutral position (i.e., motor not turning) that corrsponded to the RC controller’s joystick center position with trim set in the middle. Any RC hobbyist could understand that. And eventually BEST students would learn this as well.
Here is the manual for the HiTec SP-520 Plus Electronic Speed Controller.
The Hi-Tec EZX-R Speed Controller replaced the SP-520+ in 2004. The EZX-R was greatly improved and had a much easier setup/adjustment procedure.
Below is the manual for the HiTec EZX-R Electronic Speed Controller.
Consumables (or Expendables)
The consumables (non-returnable) portion of the kit was literally created by collected as many similar items as could be found, enough to support all teams participating. In the early years this meant annual dumpster diving at Texas Instruments to see what could be found and might be usable. Steve and Ted knew the students needs a some building materials, fasteners, tape, and other hardware. But they also looked for unique items that were being trashed that they thought might be a useful gadget for a robot.
Over time, the consumable kit became more standardized commercially available parts but still with some unique and miscellaneous items like a bicycle inner tube and a brake cable, an irrigation cover, an aluminum paint grid, clothes pins, golf balls, soft drink cans, and others. Several of the household items eventually became a list of optional items that teams could provide on their own. Many of these optional items still exist on the Consumable Kit list of today. The dot matrix printers of the early years was replaced with a unique set of belts, pulleys and bearings known as the “drive components”.