need help building a 3500 lumen LED light bar

Straight8

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Jan 6, 2008
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Hi, I am trying to gather materials to build a 3500 lumen light for night driving in the woods. LED is the newest technology and longest life so I want to use that as the base. I have a full blown machine shop so the manufacture of any mountings, heat sinks ect will be no problem.
I would like to have ideas on suppliers and what you guys think I should use for LED's to shoot the brightest farthest light I can get. any help will be appreciated. system will run off of standard 13.8 volt automotive source. Thanks
 
Maybe 20 of these optics (2 10-packs) and 20 of these emitters (remember the BULKRATE coupon it drops the price to under $5 apiece) and 7 of these converter boards (6 will run three emitters in series, 1 will run 2 in series)

You might want to tweak the angle of each emitter to get a full beam. If I were building this and I had a machine shop, I would use a 1 in. square aluminum bar about 2-2.5 feet long, evenly space the LEDs along it, and If I decided to change the vertical or horizontal angle of an emitter, I'd mill into the aluminum a few degrees. I can draw what I mean in Sketchup or Inventor if it doesn't make sense.

That will net you about ~3600 lumens, and those converter boards will run off of automotive power.
 
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Thank you very much for the quick reply. Would the CREE q-5's also be a choice?
 
Thank you very much for the quick reply. Would the CREE q-5's also be a choice?

Certainly, but the optic would have to change. Q5's would also add about $55 to the price, and only add a few lumens.
 
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Personally I would use Cree Q5 emitters. Since you have a full machine shop, I would personally use 2 of these and 1 of these to use with 21 Cree Q5 leds.

Put the 25 degree optics on either side of the 6 degree optic, and make sure you have really good heatsinking, if possible make it so that when driving cold air goes into a channel and flows out the back to cool the LED's. heatsinking is key. Just my personal choice.
 
If you want to stay cheap, I would recommend 20 Cree Q5s From DX, 7 of these drivers, 1-2 sets of these optics, and/or some other optic/reflector thing(If you really want distance, 20 aspheric lenses will work better for throw but be harder to make, look here).

That setup will give around 3800 lumen at the emitter.

Heatsinking would be important(Maybe active heatsinking?).

:welcome:
 
FWIW, I would go with rebel 100's as the color rendition is better. Though the new Q5's and such are quite an improvement over some of the older ones...
 
Can you post me up a link to aspheric lenses. It looks like these could be made waterproof fairly easy.thanks
 
What size would you like them?

You can find some on dealextreme for cheap(These). Surplus shed also has a few. Kaidomain is also thinking of selling some.

You would want the ones that are wide and have a short focus length, taht will mean more light will get focused.

This is and example of what you can do with one good aspheric lens and one overdriven LED.
 
Would the Osram Ostars not be better, at 1000 lumen each you could just have 4 lights and its done. Be much simpler to build

I've jsut started looking into these emmiters and on the spec sheets they have automotive specification mounted leds as standard.

With just 4 reflectors/optics the build will be a lot easier. The light I build will use a maxflex as the driver which will enable all sorts of controls and help manage any temperature issues as apparently they are a bit warm running :naughty:

Just my 2p's worth:twothumbs

Ian
 
This will be an awesome build - and running off auto power gives you much more options! I'm too used to building things off AA's or 123's!
 
Thanks Broz I think we are getting very close to ordering up some parts. And by the way the number of leds in this build has gone up conciderably. LOL
 
Hi, I am trying to gather materials to build a 3500 lumen light for night driving in the woods. LED is the newest technology and longest life so I want to use that as the base. I have a full blown machine shop so the manufacture of any mountings, heat sinks ect will be no problem.
I would like to have ideas on suppliers and what you guys think I should use for LED's to shoot the brightest farthest light I can get. any help will be appreciated. system will run off of standard 13.8 volt automotive source. Thanks

Straight8,

When you ask that question you remind me about one of the thougths I have had: coupling together several flashlights!
One solution: purchase 20 examples of the Fenix Digital L2D Black Premium Q5, and bind them with a rope or rubber band and you have that flashlight! :)


Regards, Patric
 
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Make the bar a full size light bar - with LEDs every inch... That's ALOT of light there! :party:

As far as I know, the current plan is for 42 emitters on a 42in. bar, for ~7500 emitter lumens, ~6500 out the front. :drool:

@Straight8, I finished two SSC mags today and the tint is great. But the emitters I used were both USXPI bin that I bought from LITEmania. The DX stars are a little more luck of the draw, but still should be alright.
 
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where we are right now is we are convinced with all the help on post and pm THANKS fellas is that we are going to do 2 bars with 42 Q-5's on each bar. I don't know for sure yet But I am planning to splay out the last 4 led's on each of the 4 rows 1 degree increasing splay each. I want the light to shoot out the front and not waist any light shooting at the ground and stars.(right infront of the bumper) I got tons and tons of help on pm but need to make a decision which way to go from here. The big question is to aspheric lense or not.
I want the hotspot to be out in front 100 FT or should I have said that I want highnoon sun out infront of the JEEP 100 ft.
Thanks fellas for all the help. please keep any offered help coming. And I promise that I will post up build pics and beam shots when done. and give credit to the folks that helped us guys build this CPF BRUTE!
Thanks againg fellas!
 
If you are going to arc the angle of the LED's and use a total of 84 LED's then you might get pretty good results with Ashperical lenses, I have seen D shape reflectors before which were great for keeping lumens from floating into the stars.

14000 lumens isn't shabby at all. Although at roughly 300 watts, you may need to up your alternator.
 
Cmon Man your scaring me! LOL! nope the alt is 120 amp guaranteed so not to concerned about that. the alt is pumping into twin blue top 982 CCA batts!
 
Well, for 100 ft and 84 aspherical lenses, the light would probably be visible in the daytime.

Maybe half and half?

Edit: optics will be easier to use. Aspherics will have too much throw and be really hard to use. 1 LED with a decent reflector will throw 100 ft easily, 84 will be much brighter.
 
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Well, for 100 ft and 84 aspherical lenses, the light would probably be visible in the daytime.

Maybe half and half?

Aspherics won't be a good solution. They are too throwy for this application, and if you defocus them, the beam is still quite ugly and full of chromatic abberation. I built an aspheric mag. I know what aspheric lenses are good for, and this isn't it. The goal is to light up a section of road about 100-300 feet in front of a vehicle, not a spot a half mile away, like the Data Bank 70-type light I see being suggested. Eight degree optics are much better suited for this project. The beam they will produce will get plenty of light downrange, and will still have enough spill to light turns and won't feel like tunnel vision, unlike the aspherics. Not to mention difficulties of construction and cost, the advantage of both lying with the 8˚ optics.
 
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