How I Built My Own MTB Light

[Drum n MTB]

I'd be interested in buying some of the lights you guys are making. Let me know if you are planning on selling any and, what the cost would be when you find out.
Thanks

[DISCO]

It would be worth buying, it is bright enough to be useful. Ahh but the work of a master is never quick or cheap.

[BrewMaster]

Drum n MTB, let us build our own and figure out the problems, then we can probably build them for other people.

For what I am thinking, 3 Cree X-RE Q5 LEDs with a nice Li-Ion battery pack that will last for 4+ hours while kicking around 650 lumens of light, the cost for major parts alone (LEDs, Driver, 14.8V 4400mAh Li-Ion battery + charger) will be about $150 plus shipping costs.

A 2 LED helmet system will be about $125 in parts + shipping cost.

Comparable retail lights are in the $400+ range, so this is still a sweet way to go. Plus, I have fun building my own.

[tkblazer]

dave, check out this light this guy made

3 ssc p4 bin led's

[boludo]

Here is a pretty simple light for ya.

http://www.customlightfactory.com/ph...topic.php?t=24

[Drum n MTB]

Originally Posted by BrewMaster

Drum n MTB, let us build our own and figure out the problems, then we can probably build them for other people.

Thats cool with me. I'm just throwing the interest out there. It looks like you guys have some pretty sweet ideas for these lights. I can wait patiently...for a while haha

[tkblazer]

check out this new osram emitter that has 6 led's on a single chip... its supposedly rated at 1100 lumens at 1,000 mA

installed in a flashlight with a standard reflector



yea its a little bright



the future of bike lights is for sure going to be LED, these new emitters are getting better and better every month

[Flat Broke]

Nam,

Do you have a link to any info on that emitter? If not, a link to wherever you found the info on the DIY light it's in?

FWIW, the spec on that other light with the 3 LEDs you showed is pretty straight forward. bFlex driver board from Task LED, 3 SSCs/Cree XR Es, and a Khatod 3 emitter optic setup.

Thanks,
Chris

[BrewMaster]

Nam, have you started cutting any aluminum tubing?

[Dino Brown]

1100 lumens from a flashlight? SWEET!!!
Wonder if one could fabricate a plug (i.e. Spookydave) for the end of the flashight head. Will make the body much smaller. Use a super powerful and super tiny Lithium battery instead.... WOW!

The "custom" mounting brackets should be relatively easy to figure out!

[northshore]

Originally Posted by boludo

Here is a pretty simple light for ya.

http://www.customlightfactory.com/ph...topic.php?t=24

This is a great option for anyone that doesn't want to have to deal with putting most of the light together on the cheap! I've been following this thread and I might go this route.

[northshore]

Originally Posted by tkblazer

check out this new osram emitter that has 6 led's on a single chip... its supposedly rated at 1100 lumens at 1,000 mA

installed in a flashlight with a standard reflector



yea its a little bright



the future of bike lights is for sure going to be LED, these new emitters are getting better and better every month

Oh my god......these prototypes sold for $750 plus on ebay.....

[tkblazer]

Originally Posted by Flat Broke

Nam,

Do you have a link to any info on that emitter? If not, a link to wherever you found the info on the DIY light it's in?

FWIW, the spec on that other light with the 3 LEDs you showed is pretty straight forward. bFlex driver board from Task LED, 3 SSCs/Cree XR Es, and a Khatod 3 emitter optic setup.

Thanks,
Chris

i found a pdf on the osram site, http://catalog.osram-os.com/catalogu...02ad85000200b6

Originally Posted by BrewMaster

Nam, have you started cutting any aluminum tubing?

not yet, will start soooon

[Flat Broke]

I did some reading and found the info on the Osram Ostar emitter that was used in those lights. You're looking around 20volts driven at 1amp for 1000lumens output.

I got super stoked when I saw the post because even driven at like 700ma, it would be bright, and have some decent run time. But those emitters are powerhungry little buggers that also throw quite a bit of heat.

On a separate note, can you believe those guys were paying $900 (with the upgraded emitter) for those flashlights? I guess they'd choke on some of our bike part prices, but still. Different strokes for different folks I guess.

Chris

[tkblazer]

yea, i read about how they need high voltage to run them... possible to use a boost/buck driver perhaps? give it another year or so and i think that emitter should drop in price.. just think though, one of those on the bars and another on the helmet using Li-ion batteries.

[Flat Broke]

There are a couple good high output boost drivers out there that could be used. The only issue then is run time. The candle that burns twice as bright, burns half as long definitely holds true here. So you'd still be looking for a higher voltage battery solution and high mAh ratings to help keep things working for a desireable amount of time.

No doubt that having the ability to dial in 1000 lumens on your helmet and your bars would kick some serious arse. And you could defintely still build a 6die based light for FAR less than current HID and 500+lumen LED offerings from retail lighting providers.

Chris

[BrewMaster]

Nam and others, lemme know when you want to order parts so we can save on shipping. I am looking to order parts after Xmas.

Can someone explain how the nFlex or bFlex drivers work? Can you switch from different mA levels on the fly with a switch? Or do you have to select your amperage and go from there? I would like to to have a low-medium-high type switch if it wouldn't be too complicated.

[tkblazer]

Originally Posted by BrewMaster

Can someone explain how the nFlex or bFlex drivers work? Can you switch from different mA levels on the fly with a switch? Or do you have to select your amperage and go from there? I would like to to have a low-medium-high type switch if it wouldn't be too complicated.

yes i believe that you wire up a momentary switch to adjust current levels on the driver. i'm too lazy to read all the pdf's but

http://taskled.com/compare.html

you can read the technical spec's on each of them

[Flat Broke]

Originally Posted by BrewMaster

Can someone explain how the nFlex or bFlex drivers work? Can you switch from different mA levels on the fly with a switch? Or do you have to select your amperage and go from there? I would like to to have a low-medium-high type switch if it wouldn't be too complicated.

The link that Nam gave is good for sorting out the different features the Task LED folks offer in their product line. There are other drivers out there, but Task LED has a good selection and have a bike orriented UI available on some models. As an example the bFlex has the momentary switch already installed on the board, while other drivers require you to solder up your own switch to the board.

The drivers are either boost, buck, or linear. Boost drivers take the input voltage from your batteries and step up the current to meet the needs of the LED. If you had a really power hungry emitter or series of emitters that draws more voltage or current than your batteries have in their natural state, you'd go this route. The different brightness levels are achieved by the driver increasing/decreasing the current (amperage) to the LED.

Buck drivers effecitively lower the input voltage from your batteries to ensure that you don't burn out the LED. So if you had a couple LEDs that only drew a few volts, but ran an 18 volt battery pack, you'd want to go this route. The different brightness levels are achieved by the driver increasing/decreasing the current (amperage) to the LED

Linear drivers don't regulate the current like boost/buck type drivers. They dim the light source through PWM dimming or Pulse Width Modulation. As I understand it, the current going to the LED is constant, but the PWM circuitry effectively shorts the LED out an different intervals to reduce the light output. Thinking of light output as energy expended over a given period of time may help to explain it. If you switch the LED on and off for say a millesecond at a time over the course of a minute, it will have put out less light than if you had left it on for the entire minute. Because the LED is turned on and off so fast, the human eye can't see the event take place, but interpolates the data from when the LED is on and off effectively creating the perception that the LED is dimmer. For the split second it was on, the LED is just as bright as it would be under normal operation; but because it was off, for a portion of that minute, it used less power and created the illusion of being dimmer. Maybe someone can give an easier to understand explanation, but hopefully that will help.

If you want to order up parts, you should figure out how much light you want and how long you want it to burn for. There are different drivers available to suit most combinations. Sort out your battery and LED choices first to get the lumens and run time that you want; then pick the appropriate driver to make the power source and LEDs compatible.

Chris

[spookydave]

I'm ready to get my hands on some LEDs! I don't think I can wait until after christmas. My lights suck and I need a new set up.

woot!~!