Do I need a START GATE to race or tune diecast (Hot Wheels) cars with the Cook’s Projects Race Gate?
The simple answer is NO, you don’t need a starting gate because using the Race Gate from Cook’s Projects gives you a car speed at a specific point and can give far better accuracy than a measured time system with a release gate. The Race Gate is a starter, by a sound and light sequence just like a Formula 1 race, and a finish line that measures time and speed of 1:64 scale diecast model cars (i.e Hot Wheels and Matchbox cars). By simply measuring the weight of the car and its release height above the Race Gate, accurate energy levels can be determined and the performance and efficiency of the car can be accurately and quickly assessed. (We have a spreadsheet to help with these calculations available for free download from our store.) An electronic release system would be needed with timers that don’t measure speed. But errors are likely to be greater with this system. So why complicate things? Read on to find out more.
To compare cars, or different track layouts, some sort of measurement is needed. With a simple timer, which can only measure time over the course, a precise release of the cars is essential. But there’s no point in displaying times to thousandths (milliseconds), or even millionths (microseconds), of a second if the time taken for the timer device to issue the start signal, plus the time it takes to travel along the wire back up to the start gate, plus the time taken to activate and release the gate and car is unknown or undefined. Using this type of timer system which may display times to 4 or more decimal places might give the illusion of high precision, in reality errors of around 0.1s will exist.
A measure of time difference over a track is an indication of performance. Average speed of the car on the track can be calculated if the precise distance travelled is known. In reality, accuracy is compromised by all the time delays in the system. For example, did you know a signal travels in a wire around 150,000 and 300,000 kilometres per second? That’s fast; but over a 10m cable that takes between 120 and 240 microseconds. Furthermore, the magnetic field in a standard electromagnet does not disappear immediately upon cutting power. For small 5V, 3kg–5kg electromagnets, this dropout time is typically 10 to 50 milliseconds - that’s up to 50,000 microseconds! Total Release Time, including the processing time and mechanical inertia of the gate releasing, is the total time from the "drop" command to the car moving is usually within 20 to 100 milliseconds. That is an error of up to 0.1 second and will significantly affect the comparison. This amount of error will still be present in a push button gate release system that starts a timer from the start gate.
The Cook’s Projects Race Gate has an internal time clock capable of measuring time intervals to 4 microseconds! And because there are no long wires or complicated starter gates, errors in measured speeds and times are significantly more accurate than wired timers can achieve. Whilst the Race Gate is designed for fun diecast model car racing and allows the start of the cars to be based on a sound and light start sequence it offers opportunity for accurate scientific analysis. Simply place and race, its that simple!
But hang on a minute! This can’t work for proper diecast car and track tuning and racing, can it?
Of course, the Race Gate can be used and is more accurate than standard timers. As the Cook’s Projects Race Gate measures the speed of each car, this allows the energy of the car to be calculated. Most race timers simply measure the time on track until a car passes the finish. With only time information you need an exact release time and so an electronic start gate to see the minuet differences tuning a car or track produce. To be accurate, the time delay of the electrical signal along the connecting wire and the time for the mechanical release to work will also need to be considered. With this method, the propagation speed of the release signal and the time the release gate takes to lower should also be considered. The signal propagation speed is based on both the wire and the dielectric constant of the material around the wire. It will vary on a case by case basis but could be as much as 240 microseconds over a 10m wire giving a further inaccuracy to the time measurements. The mechanical delay for the start gate is likely to be in the region of 1000’s of microseconds! The start gate system time to release may also vary depending on the mass of the car and its frontal area (these increase friction varying the gate lowering speed). These delays will reduce the accuracy of the measurement and reduce the value of calculations. Use these times and with additional information on the exact track length, the AVERAGE speed over the whole track can be calculated. Due to the time delays this will have significant errors and also requires a complicated mathematical calculation.
But is a car that travels the track faster better or more efficient?
A car that reaches the finish line first is traditionally deemed to be better. But it is not necessarily the most efficient.
With the Cook’s Projects Race Gate the race time and each car's speed and finish time difference is measured at the finish line. The results are instantly displayed on the LCD, and more accurate data can be sent to a connected computer. With this system you don't need a starter gate or need to worry about the error in signal propagation or mechanical release. The speed at the finish line is the measure of the car’s energy, its Kinetic Energy (Kinetic Energy = ½ mass x speed squared). By taking the Kinetic Energy and dividing by the Potential Energy (Potential Energy = mass x height x gravity), the efficiency of the car in converting potential energy into speed can be shown. This is a far better measure of car and track efficiency. The Cook’s Projects Race Gate provides much more information than a 'standard' timer can give you, with greater accuracy and no track modifications either. With these measurements, even small changes to a car’s performance, or track changes, can be scientifically assessed.
Use our spreadsheet to do all these calculations for you and show the efficiency of a car and track. Simply measure the mass of the car and its release height above the finish line. The spreadsheet can convert various units of measurement to calculate the Scientific Standard Measurement of energy (Joules) and provide the efficiency of the car. This can show even the smallest differences in the efficiency of a system when small adjustments are made.
With the Race Gate, as well as race time, the exact speed at the finish and time difference between cars is measured with an internal clock capable of 4 microsecond resolution (that’s 4 millionths of a second!). This allows a much more accurate measure of car energy and so efficiency of car and track. And it's instantaneous! The unit displays these rounded numbers on the LCD, or more precise data can be sent to a computer for further analysis and record keeping. You can download a free calculator that will scientifically calculate the energy efficiency of your setup on the Cook’s Projects website and there is a video on their YouTube channel on how to use it.
If quick comparison of two car performance is required, then any simultaneous car launching system can be used. There is no need for an expensive electronic start gate.
Check out this website or email sales@cooksprojects.com for more information.
