Wiring the Artin 1:43 Counter track piece to a PC for lap timing/counting

v Artin 1:43 now has a track piece for lap counting, part number 4921 for $6.00. This piece can be found at Slot Car World and all other Artin retailers.

v On the side and top of each track piece are three contacts; one is a common (middle), and one for each lane’s sensor.

v Looking inside the track piece, one can see the small switches under each lane. As a car drives through the two pieces of copper are pushed together and contacted, providing a signal that can be used to trigger the Artin electronic counter (part number 4924 for $15.00). So for a total of $21.00 you get a lap counter but not a real timer, nor do you have any of the neat function that the PC based software can give you.

v In the following, we will see how easy it is to connect this track piece to a PC parallel port for use with lap timing software.

v First, since soldering will be involved, we need a soldering iron. Any iron will do, provided that it has a very fine tip of 1 mm or less.

v Then we need solder and I highly recommend the use of flux, paste as shown below is the easiest.

v We also need a parallel port connector (also known as DB-25). You can find this at any Radio Shack or other electronic retail shop.

v The first task is to open the DB-25 connector. If you will used this for 2 lanes (lanes 1 and 2) you will need three wires long enough to go from the track piece to the computer parallel port. If you do it for 4 lanes (using 2 track pieces, lanes 1, 2, 3, and 4) you will need 6 such wires. In the following pictures I show wiring for 4 lanes, for two lanes ignore anything related to lanes 3 and 4.

v Connect two wires (one for each track piece) to pin 25 (common or ground) of the connector AND connect one wire to pin 10 (lane 1), one wire to pin 11 (lane 2), one wire to pin 12 (lane 3), one wire to pin 13 (lane 4). This pin assignment is only for Laptimer 2000, which is the software I use. For other software, please refer to you user documentation to figure out which pin you need to connect to.

v Don’t forget to make a knot as shown on the pictures in your wire before closing the connector to get some strain relief in your wiring so it does not brake right away if you (or someone else) start pulling on the wires.

v Once you have done this, close the connector. It is now time to test it. To do this, plug your freshly made connector into the parallel port of your computer and start the lap timing/counting software that you want to use. Every time you touch one of the wires from pin 10, 11, 12, or 13 to any of the two wires from 25, the lap timer/counter should register a new lap. Due to the properties of the mechanical switch used in the Artin track piece I would recommend to set your debouncing time to at least 2000 msec (or 2 secs).

v To learn more about testing your parallel port on your PC for lap timing/counting check Brent Carlson’s short article. Also, the best information about lap timing/counting software can be found on Brent’s site, click on the lap timing software button on the top left of the page.

v Once you have verified that your connector and software combination is working properly, it is time to connect the wires to the track piece. First remove the back cover form the track piece by inserting a flat head screwdriver and prying the cover open, be careful but don’t worry it should not break as it is only slightly press fitted in there. You the have two choices.

v You can thread the wires through the top contact openings of the track piece and then solder them in place as shown below.

v Or you can take advantage of the fact that the back cover has three small openings to the side for wiring coming in and out of the track piece and just thread the wires through there after you solder them in place.

v Now close the back cover on the track piece, simply snap fit it in place. Just make sure that the wires inside are all going through their respective wire guides or it will not close right and crunch the wires, leading to potential contact problems.

v That’s it. You should now have a fully operational sensor track connected to PC lap timing/counting software.

v The track piece is supposed to be bidirectional, however I have notice that one direction seems to work a little better than the other. Also, if you experience problems with the lap counting, the first thing to do is to open the track piece and bend the copper contacts for the guilty lane towards each other so they touch a little bit more easily as the switch is actuated when a car goes through. I would say that after about 1 hour of testing the stuff I have had 1 or 2 missed laps, which is not great, but not bad either.

v Another thing is to make sure you place the track piece in a slow section of your track, maybe right before a tight turn. It is also better to put it before a turn than after as after a turn cars might have a tendency to slide around which might affect how they actually push on the mechanical switch in the slot. Also, I have noticed that heavier cars have much less problems with triggering it than lighter ones.

v The same applies to the 1:32 lap counting track piece that is available from Artin (part number 5721 at $8.00)