Let me start with this: I love biking at night. Everything from the empty streets to the cool air keep me biking into the night. But my quick setup of a LED flashlight pipe-clamped to my stem was not cutting it. I needed more power. I needed a true headlight.
And so was born my second LED lighting project. It totaled about $150 after several trips to the hardware store and a custom water bottle battery pack. 1300 lumens is about the total output of the LED star, the actual output through the lens will be about 10% lower. It is still comparable to both of my car's headlights combined and, even when under-driven, is plenty bright for any biking needs.
Fun Feature - The b2flex board is capable of flashing the LED in a strobe pattern at full strength with an effect similar to a police dazzler. NOT recommended for biking. Blinding muggers and spontaneous rave parties, maybe.
CREE XPG R5 3-up star
3-up Carlco Optics
Arctic Alumina Adhesive (Note: Needs to be the ADHESIVE)
CPU Heatsink I choose this on based on size and a radial design for looks, Personal Choice.
B2Flex LED driver To save money one could use a buckpuck from LEDSupply, I wanted the extra features.
2.5mm Plug (I reused some broken headset cords)
Off-mom-on button: Any will work as long as you can easily push it.
Any 3mm or 5mm LED, low power.
Handlebar Mount Be sure to measure your own handlebars to get the right size.
Lexan - At least 3x3 Square, any thickness
1 inch PVC slip plug
Aluminum bar -at least 1" wide, 1/8" thick
-4 10-36 thread 1 1/2" machine screws with fitting locknuts and washers
-4 small machine screws, max 3/8" long
-A 1 1/2" x 1/4" machine bolt, hex head with matching nut.
1x Female Tamiya Connector
1x Male Tamiya Connector
14.4v Battery Pack The size is only dependent on budget.
Double-Conductor Cable: I used a old lamp cord
Cheap Water Bottle- Bigger than battery pack
Optional - 3" heatshrink
The battery pack is only NiMH due to the cost of starting a lithium setup from scratch. If you have a 4-cell charger, a lithium pack would be the cheaper (and lighter) route.
Step 1: The Driver enclosure
First, the mounting holes for the board and holes for wires were drilled out. I then used machine screws and nuts to clamp the board down. Nylon screws and nuts should have been used but it is what I had on hand. No matter what method you use, be careful on how tight you secure the board. The Inductor on the back is brittle and cracked when I tightened down on it.
The interface holes include LED power, the 2.5mm jack, status LED, and battery connection. Sizes will of course vary depending on what cabling and status LED you use. An 1/8" drill will get you pretty far though. To keep wires short, I soldered connecting wires after the board and components were mounted.
To follow my order, install both the 2.5mm jack and the status LEDs without the board installed. Hotglue works for the LED and the jack should be panel mount i.e. clamp right to the enclosure. I had to use a scrap jack and JB weld it in.
Next begin to install the battery connector and the LED leads. For all board soldering, a flux pen is essential. Use a pencil tip iron and carefully begin to add the connections to the board. Connections should be labeled and easy to figure out; consult the b2flex manual if you are confused.
A final bit of hot glue for the battery and LED leads for strain relief finishes the enclosure. Two holes in the corners opposite the closure screws will be used to mount the enclosure to the heatsink.