DIY Offroad LED Light Bar

Good work mate you beat me to it. I’ve starting modding a small light bar for my girlfriends car. It’s 12 inches so it sits inside the bumper. Output aim in 10-15k lumens I was going to go crazy and use XHP70s but it will cost to much. I made my own heatsink also. I am not sure about where to mount my driver.
I am more worried durability then output I think.

excellent build …I run ebay cheapies they leave a bit to be desired…
thanks for posting

I’m sure you can make a better light bar than what you can get off the shelf. You can space 20mm lenses and star boards 25 mm apart, so 12 LEDs in 12 inches, you can easily get 12,000 lumens using XM-L2s. http://www.ledsupply.com/leds/cree-xlamp-xm-l2-leds?gclid=EAIaIQobChMIya2939Wy1QIVkTRpCh3ohQAwEAQYASABEgInw_D_BwE

The Carclo website has beam patterns for their lenses with practically every LED available. You can get lenses for the XM-L2 in spot, flood, or elliptical and design it how you want, for example: http://www.carclo-optics.com/optic-10003l25?opticfamily=20mm Once you find the pattern you want, you can get them from LED Supply or Mouser.

I’m looking forward to seeing your build!

That looks really sleek! I like the logic behind your roof rack mount as well. There are quite a few examples of mounts just above the windshield which can cause whistling/wind noise problems and the thought of glare or the hood lighting up didn’t even occur to me. This seems like an achievable project for the DIY’ers but aligning the drilled and tapped screw holes must be difficult. If you don’t mind, just a few follow up questions for you.

Can you tell us a bit more about the size and dimensions of the heat sink and c-channel you made?
Are you going to modify it in the future with any thermal management circuit?
Any plans on upgrading the current from 2A to 3A?
Any condensation or moisture problems so far?

Wow that is some awesome work and awesome pics in your post. Please let us know how those drivers hold up, I’ve been considering them for similar projects, on a much smaller scale :smiley:
What made you choose the xp-g2 out of curiosity? Is you’re truck set-up with an extra battery or high-current alternator? Noticed any electrical changes or anything while running El Jefe? Thanks!

The problem is so bad there is a guy who is making a small business out of fabricating and selling custom visors for light bars: https://www.tacomaworld.com/threads/roof-mounted-led-light-bar-glare-solved.377416/
Some people even paint their hoods black.

I plan to add a low voltage cutoff to turn it off before the car is unstartable. I could add PWM dimming based on temperature, but it has enough heat dissipation to operate at 100% even in the worst case scenario (100F) weather, so I probably won’t bother. Maybe the next version.

Most definitely. It seems to run much cooler than my prototype tests on the kitchen floor. It was on for a couple of hours in ~90F when I took those night shots and I was surprised that it barely got warm to the touch. I’m going to borrow a large battery charger and test it on the car inside the garage so there’s no air movement and up the current as much as heat will allow. I’ll rerun the power with at least 10ga too.

So far so good. I saw Gore vents mentioned on somebody’s website, read Gore’s paper on the root cause of condensation, and bought one on eBay for the heck of it. Maybe it works, maybe it’s a placebo.

I picked the XP-G3 for the most lumens per watt, with the desired beam pattern with a 20mm Carclo lens. I spent a lot of time on Carclo’s website comparing beam patterns and LEDs. The XM-L2 is too fat. The XP-L HI is too expensive.

No, it draws about 25A, so probably no more than the rear window defroster.

You can definitely hear the idle change when switching it on an off, but that’s it.

Shot #3 made me giggle as the hill appeared out of nowhere.

The whole thing is 1143mm wide, or 45.0” - the exact width of the Pathfinder roof. The channel was made from 1.25”x2.5” rectangular tubing, .125” wall. After cutting off one side it is 57mm deep.
This is the heat sink: http://www.heatsinkusa.com/3-945/

Excellent job and results. I share your views on off the shelf units, and had wondered if anybody here had ventured into this realm for DIY. I’ve been researching these, as I can recess a 32” light bar in my Colorado’s front bumper, but everything seems sub par on output lumens/pattern vs price vs quality complaints.

Wow, great job!
Makes me want to get myself in to gear and build the custom light bar I’ve always coveted.

What did you use to cover the front of the light bar, the “lens”?

Would plexus glass work?

The faceplate is made of acrylic, which is the generic name for Plexiglas. Everybody else uses polycarbonate (popular brand Lexan) which is stronger, but polycarbonate turns yellow in a couple of years. Acrylic does not yellow.

i was told by a big light manufacturer that PMMA (acrylic) could not take the heat.
and they said they treat polycarbonate so it doesn’t yellow.
are they blowing smoke?
why are most LED lenses made of PMMA if they can’t take the heat?
i’m about to have lenses made and i need to know which to use.
thanks

I’m not an expert, but Wikipedia says PMMA (acrylic) has a glass transition temperature of 105C and polycarbonate at 147C. So if your light is going to be hotter than boiling water, it could be an issue.

Auto headlights are made from polycarbonate and they have a coating to block the UV and keep them from yellowing. You’ve probably noticed how well that holds up.

So I finally got to perform a real-world heat test in the desert last month. It was dusk, 80 degrees F, no wind, and I remembered to bring my thermometer.


Ambient temp, 79.9F


I told my friends why I was running up to my car every two minutes and taking it’s temperature, but they weren’t really interested. They just sort of expect me to be doing weird things.


Starting temps normalized to 100 F/ 37.8 C, because my criteria was it would operate in 100 degree weather, parked, with no wind. The real world operating temperature was significantly lower than the prototype on the kitchen floor. A slight breeze came up around the 20 minute mark so I discount the data after that, but overall, I think I can take the advice of BLF members and increase the current from 2A to 3A.

I’m not going to change this light bar, however. I’m going to build a new one with Carclo 26.5mm optics instead of 20mm and use XP-G2 instead of XP-G3. I’ll have to increase the height of the bar from 1.25” to 1.5”, and reduce the number of LEDs from 45 to 36 to accommodate the larger lenses. I hate making the bar taller, but the vertical distribution is just too floody. I should complete a 6 LED proof of concept in January, and if the pattern meets expectations, start on El Jefe 2.0

Well done again. You have put so much time and effort into this light. simply ORSM. :+1:

Accurate color as in the pic? Looks nice and warm! :heart_eyes:

Yes, 4000k. I think it’s a little too warm, and 5000k is a little too cool. I’ve been experimenting with using half of each and I like the results.

4500K is the border between 4A/4D (below BBL, rosier) and between 4B/4C (above BBL, greener), so the common-as-dirt 4C would be perfect.

In my S2+ with a TIR lens, which mixes the light better and avoids the fried-egginess of reflectors, the 4C is beautiful. White with just a touch of warmth.

’Though, even my 3000K lights at night just make everything “pop”. Takes a bit getting used to, when everything and its grandmother is “cool white”, but once you do, you don’t want to go back. Now, even my 5000K lights look “cool”.

I must doing something wrong. I’ve searched for XP-G2 S4 4C and for XPGBWT-01-0000-00LE4 but no dice. Any pointers?