Step 2Mark & Drill Holes

We'll start off by marking holes in the Altoids tin that is going to be fitted to the bike itself.

With the Altoids graphics on the top of the tin facing you, using a marker pen...

1. Left Side - mark 2x 5mm holes about 10mm apart. These will be for the cables that connect to the 16x2 LCD.
2. Back - 2x 5mm holes. One will be for the reed sensor cable and the other to mount the external antenna.
3. Right Side - a single 5mm hole for the cable to the 9v battery.

Once you've marked out, find a secure means of holding the tin in place while you drill the holes. As I found out in my first attempt, it can actually be quite difficult to drill holes in the tin without the metal deforming. For best results, I found that starting with a 2mm bit as a pilot then gradually increasing size of the drill until you reach 5mm worked well. I also tried using a bodkin/skewer which was really great because it slightly pushed the material inwards, making the PVC tubing much easier to insert in the following steps.