Bike Light DIY Newbie - CREE ?

[peteredm]

Firstly thanks for having a read, trying to work out a parts list for a bike light project as I commute everyday and the winter nights are drawing in.

From initial reading thinking a collection of cree leds over luxeon star as the lumen per watt will be better?

Aiming for a minimum lumen rating over 500, how many cree led units would I need and could any one recommend lenses/optics so I get one with a intense spot and the others with a broader range to get a good spectrum/balance?

If I'm right a driver is needed, again could anybody recommend a good unit to facilitate different brightnesses be it by switching leds of in turn or by power to all leds?

And battery cells any pointers ?

Thanks again appreciate I'm asking a lot of questions so if you'd rather recommend some good links not a problem.

Pete

 

[Hack On Wheels]

I would recommend going to forums.mtbr.com and searching for the "achesalot triple". Also take a look at this thread: http://forums.mtbr.com/showthread.php?t=295664

I made one of the triples with 3 XR-E R2 emitters. It should put out 700+ raw lumens, and say 600 or so lumens with losses from optics and all factored in. I'm using Ledil square optics... 1 Medium to at least slightly illuminate everywhere my eyes can see, 1 Real Spot for good punch/throw (it looks terribly ugly though!), and then 1 Smooth Spot for more throw while looking better than the RS and spreading the beam a bit wider. This is by no means the best combination, but it gets the job done pretty well, and I only notice the ugly hotspot when I'm not riding on trails. You could try 2x Smooth Spot + 1x Diffuse, or 1x Smooth Spot + 2x Diffuse for a "prettier" beam.

There are more compact bike lights for sure, but this is big enough that its easy to make, yet small enough (great low profile) that its never an issue while riding. I use mine on the helmet and I can easily ride with it as my only light. (I did, however, make a single R2 bar mount light for a bit of immediate lighting on the trail.)

 

[John_Galt]

I' would suggest going for the new XP-G LED (there's a really good thread in the LED sub-forum). It can put out a maximum of ~345 lumens @1000 milliamps, as opposed to ~250 lumens for the the Cree XR-E platform.

The XP-G is the same platform as the XP-E LED, but with a larger die, so apparently, XP-E optics will fit, but they won't be as tightly focused as with XP-E's.

I've been in the design stages of my quad light (to run from a really weak stator), and so far I've figured that a set-up of three LED's and optics combinations would be best.

My design is such that the first LED on the left would be a local flood light, the middle would be the spot, and the far right would have an rectangular optic (~15*35 degree beam pattern).

But the number of combo's is incalculable. It depends on your personal prefernce, skills, and budget.

 

[peteredm]

Anybody know of any good suppliers of the cree led's in the UK?

Just had a look on RS's website and only list a few items