Pinewood Derby Stories and Photos from Maximum Velocity
FEATURE ARTICLE Electric or Human Eyes: Take your Pick by John Shreffler
When they needed to go a distance, our great grandparents traveled by horse and buggy. Some groups in our society still do that, but there are drawbacks in terms of convenience, time, and energy. Most travelers have found that the automobile or airplane just does a better job.
History of Finish Line Judging
Likewise, when pinewood derby racing appeared on the scene some fifty years ago, the only way to determine the winner was to use the human eyeball. Some groups still do that, perhaps for reasons of frugality, or nostalgia. But there are drawbacks. Pinewood derby races are typically very close, and it is often impossible to eyeball the winner, much less the finishing order. Often, the audience (invariably the parents) will get into the act, and dispute the official's call. And this is where things break down. Some officials stand firm and risk looking like they are partial or stubborn. Other officials might respond by allowing re-runs on contested races. But once this happens, typically, almost all races have to be re-runs. Tales abound of poor parenting examples, and perhaps the worst part is that children with less aggressive parents are at a disadvantage. The time wasted and the hard feelings generated are a serious drawback to the intent of this otherwise fine youth activity.
Technology of varying degrees has been tried over the years. One early low-tech approach was to place a paper cup on each lane. The idea was that the flying paper cups would be easier to interpret than the position of the bumper of a blur. Not much help, however. A higher tech approach was to use a video cam-corder, and play each race back in slow-motion. Not all that much help either, and all it usually did was to drag things out for hours longer than anyone expected.
The basic problem of pinewood derby racing is that the parents demand accuracy in judging. But the kids just want to see their cars moving on down that hill. What a dilemma!
Technology, as it often does, has come a long way. These days, it is possible to run a pinewood derby race every thirty seconds, with complete accuracy, no ties, no parental second-guessing, and no angry words. How is this possible? Ask any organization that has made the big switch to electronic finish lines. They are instant believers and only wonder what took them so long to see the light.
Who am I?
Hi. I am John Shreffler, and I make an electronic finish line called 'The Judge'. I got started in this adventure many years ago when my son was in Cub Scouts, and as fate would have it, I got 'volunteered' out of the audience to be a human judge. I saw immediately that this was no job for amateurs. The next year, I came to the derby with a crude homebuilt optical finish line and it was an immediate hit. I saw the possibilities and went for it. Against my wife's cautions, I gambled the investment in parts, and the rest of the story is history. Finish Line Options
Naturally, I must keep very aware of the pros and cons of the various finish lines available on the market. Options and features abound, and they can be confusing to the uninitiated. Which are essential to a smooth race? Which are nice to have and why?
To answer these questions and to give you a better idea of what to look for when selecting a finish line, I have listed the various features and options available for finish lines. I have also categorized them by whether they are essential or just nice to have. Essential Features
Accuracy - At the finish line, a difference of one-thousandth of a second (0.001) equates to about 1/8 inch. Thus, to eliminate ties and to achieve the most accurate results, the internal accuracy of the finish line should be at least one ten-thousandth of a second (0.0001).
Dependable Sensors - Most finish lines use infrared sensors, which trigger when the front edge of the car blocks the overhead light source. This method is quite dependable and is immune to reflections, flash photography, etc.. An alternate method is track sensors which are triggered when the front edge of the car physically contacts a sensor. Depending on the quality of the switches, this method can also be dependable, but some prefer to not have the car physically touched when passing through the finish line.
Finish Line Read Out - It is important for the audience to immediately see the results of the race. For smaller events, a read-out on the finish line works well (for larger events, consider a computer interface with the results displayed on video monitors or projected onto a screen). Some models offer flashing lights to indicate first, second, and third place; while other models use numeric readouts. Either will work, but the flashing light method can be seen and interpreted from a distance and from a wide angle, while numerical readouts require the audience members to sit closer to the finish line and at a more direct angle.
Note that some systems offer a remote readout, which can only be viewed by officials. This method may not instill as much audience confidence, as the results must be interpreted and announced by an official (Editors note: If your track has a remote readout, always have two officials monitoring the results).
Nice to Have Options
Timer - A timer option is great to have. Even if the race is not scored using elapsed time the timer can be used to show the advantage/disadvantage of design techniques during workshops and to compare the results from year-to-year. If selecting a timer option, make sure it is accurate to one ten-thousandth of a second (0.0001). While .01 second is fine for cross-country skiing, it simply won't do for pinewood derby racing.
Computer Interface - Computer interfaces are finding broad acceptance as the best way to manage races. This option is not simply for the display and automatic recording of race results, but for the seamless interface to popular derby management software packages. Many customers report that because of the ability to interface with race management software, their group is asked to sponsor regional meets. Some have paid off their investment by providing a race management service to organizations without a track.
Today, most finish lines use the PC's serial or parallel port. With the wide-spread acceptance of USB (Universal Serial Bus), and the eventual phase-out of the serial port, be watching for finish lines with a USB connection.
Outdoor Use - Natural sunlight is rich in infrared light, causing standard infrared sensors to trigger erratically. So, if your race will be held outdoors, make sure the finish line is equipped with sensors designed for use in sunlight.
Battery Power - A final possible option is battery operation. During a pinewood derby, power, audio, and video cables are generally strung in all directions. Eliminating the need to power the finish line means one less cable to tape down, and one less power source to locate.
When it comes to judging pinewood derby races, clearly the electronic eye is superior to the human eye. There are no ties, and no need for re-runs. Everyone trusts this method of judging. Your pinewood derby will run smoothly, finish on time, and leave everyone happy and looking forward to next year. It just doesn't get any better than that!