My first instructable, it pretty simple to make, and cheap as well (less than 35 HKD), although you will need soldering equipment. I functions as a torch, head lamp and bike lamp!
2 coffee cups
1 elastic band
1 9v battery
1 9v battery snap
2 Velcro straps
Step 1: Setting Up the Cup
Get your first coffee cup and cut in in half (4-5 cm). wrap the inside of the cup with aluminium foil, and poke some holes in the bottom of the cup with a needle (the number depends on the number of LEDs you are using) KEEP THE TOP BIT OF THE CUP!
Step 2: Connecting the Wires
Now that you have your cup ready, you can start soldering. push the LEDs through the holes in the bottom of your cup, then bend the wires at the bottom so they are touching, remember that the longer end is the positive end, which needs to be touching the negative end of another LED. Connect them together using solder and don't forget the resistor and the battery snap.
Step 3: Adding the Strap
Now stick some card to the bottom of the coffee cup, then cut the elastic band to the correct length (so that it wraps around your head tightly). then stick the elastic band to the card. Sew the wire of the battery snap to the left of the elastic band. Then cut another piece of elastic band and sew them on the main one, so that the battery fits through it. Finally, sew the Velcro straps to the ends of the elastic bands.
Step 4: Making the Handle
unwrap the top bit of the second coffee cup off, remember the top of the first coffee cup, cut the very top of that off, and put it inside the second coffee cup. secure it with tape. your're done!
Step 5: '3 in 1'
the instructable itself can be put around the head to become a head lamp, wrap that around the pole of the bicycle and it can function as a bike lamp. To transform into a torch, put the main part into the second coffee cup.