3D Printed Bike Headlight

Making your own design has something special: It is unique, you choose every single detail. Sometimes it is cheaper but the real added value is maybe the knowledge you get, the emotions (fun or frustration) and the fact that this object is designed for your specific needs.

If by chance you have the same needs, feel free to download this design. In the worst case you will have to adapt the the diameter for your handlebar.

The reflector is pretty standard as it is made of soda can. The LED with the heatsink are also standard.

Tools

• 3D Printer
• Drill
• Knife
• Abrasive sponge
• Lasercutter (optional) or jigsaw
• Soldering iron

Material

• LED (1W White 100 lumen)
• Plexiglass 3mm (50 x 50 mm)
• Soda can (25cl) ø 53 mm
• PLA or ABS for printer
• Electric wire
• Screw and nut (M5 x 15)

Download the parts and print them.

During this time, cut the bottom can and polish it. Drill the center to let the LED passing through.

CAUTION: Avoid contact between the pins and the can, this will cause a short circuit.

Then cut a plexiglass disc ø 43.5 mm (with the laser or jigsaw). Ideally the disc should press fit the bottom can (if it does not, use glue).

Solder the wire and press fit the plexiglass and the printed enclosure. Secure the lamp to the handlebar with the screw.

Connect the power supply (Battery, Dynamo) :

LED have to be current controlled. There are many ways to do that but the simplest is to use a resistor in series. I have a 5V regulator on a hub dynamo and the datasheet sais that the LED max forward voltage is 3.4 V. Then I should have 5 V - 3.4 V = 1.6 V on the resistor.

Also the LED max current is 1W / 3.4V = 0.3 A. So the resistor value is 1.6 V / 0.3 A = 5.3 Ω.

The power dissipated in the resistor 1.6 V * 0.3 A = 0.5 W. As I have only quarter wats resistors, I used two 10 Ω resistor in parallel (cf. image).