INSPECTION AND INSTALLATION OF TIMESTOPPER T-III FINISH SENSORS (Refer to Figure 1)

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1. Check the operation of the unit as soon as you receive it by holding the three Finish Sensors a few feet from an incandescent bulb, with the lensed ends of the sensors facing toward the bulb.   Insert a battery into the battery compartment and turn the switch to ON.   No lights should be lit on the display.   Pass a finger over one sensor and a green light should light.   Pass a finger over a second sensor and a yellow light should light.   Turn the switch to OFF and back to ON.   Repeat this blocking of the incandescent light from a first and then a second sensor until all combinations of first and second positions are tested.   Before placing the Finish Sensors into holes in the track, choose them to correctly correspond to which lane numbers are associated with each lane. It is advisable to mark the track lanes with their desired lane numbers.



2. Be careful to mount the Finish Sensors in each lane along a common finish line.   First draw (or score, or paint, or tape) a straight reference line perpendicular to the lanes at the finish line.   Then drill the sensor mounting holes along this line as described in the next paragraph.   This line will be the official finish line.



3. At the finish line and on the centerline of each lane of your track, drill a hole 5/16" in diameter vertically through the track.   The figure (Figure 1) shows how the Finish Sensors are to be installed and how they operate, whereby each car crossing the finish line interrupts the overhead illumination from reaching the Finish Sensor located on the finish line in the middle of that car's lane.   This figure also illustrates the installation of a Finish Sensor within a 5/16" hole (see next paragraph).



4. The provided rubber tubes allow the Finish Sensors (the phototransistors) to be easily inserted snugly within the drilled holes.   Each tube is slit down one side (lengthwise) in order to allow a Finish Sensor (phototransistor) to be gently inserted within the tube before installation of the resulting sensor-in-tube sub-assembly into the track.   When installing Finish Sensors, be sure to position the lens of each sensor about 1/4" below the top surface of the guide rails of the track.   From the underside of the track, and using the rubber tubing provided as a protective sleeve around the body of the sensor, insert each sensor body snugly into its respectively chosen hole (per lane number associations made in step 1 above).   The body of each sensor should be positioned within its respective hole in the track such that the small transparent window is facing skyward.   By recessing each sensor about 1/4" below the top surface of the track, the portion of hole and tube left above the lens of the sensor should act somewhat as a tunnel to the sensor to partially shield it from light sources other than directly overhead.   The extra length to each tube allows you to easily grasp it from below for removal when taking down a track for storage.



5. Mount an incandescent lamp directly above the finish line of the track to illuminate all three of the Finish Sensors.   Mount this bulb about 5 feet above the track surface.   Multiple lamps may be positioned across the finish line, and these lamps may be placed closer than 5 feet.   Proper operation of the sensors requires good illumination on each sensor (when there are no cars over the sensor holes).



6. It is recommended (particularly for critical races like pack derbies) that you use long life batteries with Timestopper and that you always be equipped with a spare, fresh battery.



7. Next read the section on OPERATION OF THE TIMESTOPPER MODEL T-III.

IMPORTANT: To protect each Finish Sensor from potential damage caused by excessive pull on its cable, clamp each cable securely to the track within 4" to 6" of the respective sensor, leaving some slack between the fastening clamp and the sensor.   Also remember at the end of a derby, before taking your track down for transportation and/or storage, to remove the sensors and cables for their protection.