The bullet then passes through the second screen, releasing the short rod, which again triggers the chisel to make a second mark on the long rod. We know that the distance between the IR "beams" is exactly 4 inches. So all we need now is to know how long it took the projectile to travel from beam #1 to beam #2. This is what Timer1 is used for. Every instruction cycle (83.3333 ns) the value of TMR1H:TMR1L will increment. When an object breaks the first beam the microcontroller starts a timer (Timer1). This timer will keep running until the object breaks the second beam or the timer causes an interrupt (on the 65,536th instruction cycle). If the object breaks the second beam before the timer causes an interrupt, it will stop the timer and read the 16-Bit value in the registers TMR1H and TMR1L. We can then calculate the amount of time that it took the projectile to travel the length in between the IR beams, which are 4 inches apart, and find the speed of the projectile.

After you have drilled the two holes for the IR transmitters, put the drill in the second hole you drilled and make sure it is completely perpendicular to the PVC pipe (there is pictures for most of these steps). Drill through the other side of the PVC pipe. You have just drilled out the hole for the second IR detector. Next, flip the pipe over and measure 4" across the pipe from the exact center of the second IR detectors hole. Make a mark and drill another hole, this one is for the first IR detector.Seeing as I am polling the IR Detectors and waiting to see when an object has broken beam #1, it takes 8 instruction cycles per loop when I am trying to detect if there is an object breaking the beam. Then once it has detected an object, it has one more instruction cycle to perform because it has to start Timer1. After it has done all of this, it has begun recording the time period that it takes the projectile to travel from beam #1 to beam #2. The same goes for beam #2. It takes 8 instruction cycles per "detection" loop and one more instruction to turn Timer1 off. Therefore the worst case scenario is: Then the circuits are changed so that the electricity comes to each magnet through a wire screen. The rods are re-hung on the electromagnets. The reason I don't drill through both IR transmitter holes and instead I measure 4" from the second IR detector hole is for accuracy. It is to ensure that both IR transmitters and both IR detectors are spaced exactly 4" apart from each other. This minimizes the error in the calculations and allows for greater accuracy.

Please note that your goods may be sent to you in instalments as availability of products can vary. For example certain products have specific delivery requirements which are explained below.

The True Ballistic Radar Chronograph measures actual speeds at four different velocities readings from 0 - 300yrds to determine actual ballistic coefficient using G1/G7 drag models. This provides actual data in your conditions, info that provides the difference between a hit and a miss. Whats it worth to you to hit your target? Use the on board display or connect to the FX Radar app to get more out of the ballistic data. Features