First off, I must confess, that this is part of my own Scalextric collection, not part of someone else’s. I’ve always enjoyed slot car racing and a lap counter is an essential addition to anyone who wants to prove that they’re the fastest around the track! Trust me, it can be very addictive, especially when racing against one’s better half.
Anyway, I wanted to share this little repair in the hope that others might benefit.
My once reliable lap counter started to miss laps on lane two at very crucial stages of a race. It started by only happening occasionally before completely missing several laps in a row, forcing a stewards’ enquiry to settle the race finish times. Lane one was fine.
Time to get out the screw driver and delve in to the workings of the timer. Once removed from the main track layout, the back of the unit has a cover which is held in place with six small self-tapping screws. These come undone easily and removing the back reveals two sets of electrical switch contacts, operated by a lever on each track, just under the slot car rails. The idea here is that the slot on the slot car operates the lever as the car passes the lap counter track piece, operating the switches contacts, completing a circuit, thus counting the laps.
Comparing the switch contact clearances, lane one’s was considerably closer than lane two’s. This means that the ‘dwell’ time on lane two’s switch would be less that the switch on lane one, which was working ok, meaning a possible cause of the problem. To anyone who’s adjusted contact breaker points on an old car, you’ll know what I mean here.
I had no idea what the correct clearance should be, so took an educated guess and closed the gap to about 0.5mm, done by eyesight alone. I made sure that both sets of switches were the same (see photos). While I had the counter in pieces, I cleaned the contact surfaces with a little electrical contact cleaner, just for good measure.
After re-assembly and re-fitting to the track, a few test laps with my fastest race Mini, proved that the counter was working as it should once again.
Cost of a replacement counter (second hand) circa £12. Cost of the repair; 10 minutes tinker-time.