Super Bright Dual Cree Led Bike Light

by axlejor in Outside > Bikes

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Super Bright Dual Cree Led Bike Light

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This project was inspired by the desire to do nighttime mountain biking,  but not wanting to part with $500+.  It took a long time to build, but the results were well worth it.  Total cost of project was about $200 for parts and material.

I used 2 CREE MC-E LEDs (http://www.cree.com/products/xlamp_mce.asp).  They are rated at about 400 Lumens each at 350 mA.  I am running them each at 500 mA in my application, so I figure they are putting out well over 800 Lumens total.  Each CREE led has 4 dies which are wired in series and then the two LED units are wired in parallel.  The power from the battery is regulated by a 1 amp buck boost with a external potentiometer for adjusting brightness.  I am using a 13.7 volt battery pack scavenged from a old nightrider HID light.

The housing was all machined by me on a vertical mill.  I started with a piece of billet aluminum and machined the basic outer shape, drilled the holes and end milled the interior.  Then I used a band saw to split it in two pieces and re-machined the rough surfaces with a fly cutter.  Then I tapped the holes, bolted the two pieces back together and then made the heat sinks with a slitting saw.  It was much more involved than this, but this is a brief description of the basic process.

Once the machining was complete, the led stars were epoxied in place with Arctic Silver Thermal Epoxy and wires were then soldered the  LED stars.  I connected to the battery by cutting a Nightrider extension cord and using the original male half to connect to the battery and adding a new screw-on-type connector to the light.  I used one spot and one medium angle lens.   Because it can be separated into two pieces, the lenses can easily be swapped out.  

I went a little crazy with the heat sinking, but it is never warm to the touch even after an hour ride.  The key to longevity with these high powered leds is keeping them cool.  

The light is attached to the bike using a Planet Bike handle bar clamp.  I machined an adapter that slides right into it and locks in place.  I should mention that Author kc6qhp made a smilar adaptor for his "Kilo Lumen Bike Headlight" and I should give him credit for that idea.   I have not provided detailed parts info due to the nature of this contest, but I am happy to provide it if there is interest.

I have attached two videos of the beam shots, it really does not do the light  justice, mostly due to my poor skills at taking a video.