Stanley knife, or very sharp bladeScrew cover
Small drill bitInfra red LED (Maplin code CH10)
Hot glue gunScreened cable
Soldering iron and solder3.5mm mono jack plug (Maplin code HF81) Step 1
Start by using a very sharp knife to remove the small plastic hinge joining the two sections of the screw cover together. Step 2
Using a small, sharp drill bit (I used 3mm as this matched the diameter of the cable I was using), make a hole in the side of the base. As the plastic is quite soft, it is advisable to twist the drill bit by hand between forefinger and thumb. Remove any stray pieces of plastic with a sharp knife if necessary.
The base should now look similar to this.
With a sharp knife, make a small notch in the cap to accommodate the cable. Check that the cable will fit the notches by temporarily assembling the two parts with the cable. If necessary, enlarge the notches with a sharp knife and re-check. Step 4
With a sharp knife, strip the outer insulation from the cable, taking care not to cut or damage the screening underneath. Twist the screening conductors together as shown.
Tin the end of the twisted screen, leaving 2-3mm of untinned wire remaining. This allows the wire to flex enough for connecting to the IR LED in the next step.
This is the infra red LED. It has a small bump on one side which acts as a lens.
Carefully bend the LED legs and cut to approximately the length shown. Take care here as it is easy to break or crack the plastic casing. Long nose pliers and patience help. Step 7
Solder the screen to the cathode, and the inner wire to the anode of the LED. The cathode on this particular LED is the leg that extends into the body underneath the bump. If using other IR LEDs, then you should check the appropriate data sheet. Care should be taken to ensure that the soldered LED and connections fit inside the...