From Farkin Wiki
- Original Thread & Discussion
- http://forums.farkin.net/showthread.php?t=54292&highlight=jds+stopwatch
- Author
- Jda
After searching for a stopwatch for my DH bike with a remote start/stop button and finding out that the popular Shimano unit is no longer in production I decided to make my own (see pic 09), here's how:
The stopwatch I used is from Dick Smith Electronics and costs around $10.00, I also had to purchase a switch $2.00 for my remote start/stop button (see pic 01)
. The switch is the type that activates in one action i.e. no click on, click off, just push. You will also need some wire, I used a piece of old speaker wire leftover from my car stereo.
The only tools you will need to modify this stopwatch are wire cutters, a small screwdriver and a soldering gun.
Step 1: Remove the screws in the back of the stopwatch and remove the back plate (see pic 02).
Look at how the start/stop button works, as you push the button in a small metal rod pushes a metal tag which contacts part of the circuit board and activates the stopwatch. This action needs to be recreated at the switch so one wire must be soldered onto the metal tag and the other onto the circuit board where it contacts (see pic 05).
Step 2: Remove the start/stop button from the stopwatch then remove the metal plate for easier access when soldering (as shown in pic 03).
This metal plate needs to be sanded on the tag where you are soldering or the solder won't stick.
Step 3: carefully drill out the hole where the start/stop switch was to approximately 6mm (see pic 04),
this give room to run the wires into the stopwatch from the switch. Now solder the two wires (as shown in pic 05) make sure your wires are long enough to reach across your handlebar from wherever you want to mount the stopwatch.
Step 4: Solder the other ends of the wires to the switch (see pic 06),
use some electrical tape to insulate and protect the back of the switch once soldered. Next get some silicon and fill the area around where the wires go into the stopwatch (see pic 07). This will dry as a firm but flexible joint and stop the wires getting broken at the soldered joints (see pic 08).
Step 5: Once the silicon is dry its time to mount the stopwatch to the bike (see pic 09). I kept everything below the handlebars as much as possible so if you crash the stopwatch or switch will not get damaged. Mount the switch next to your handle grips so you can start/stop the timer whilst riding without taking your hands off the bars (see pic 10).
