CXB 3590 flashlight build from scratch

Flashlight Modding and DIY Parts
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I have never made a flashlight before and I didn’t use any guides for my build. I came up with pretty much everything by myself so the build might seem unorthodox. Also this is my first post here on BLF. Anyways, I started with a Cree CXB 3590

I struggled finding a heatsink in a convenient shape. I ended up buying this heatsink that is meant for a ceiling mounted bulb.

But the core/center is hollow and I wanted a big, flat and solid mounting point for the LED. So I so I machined a wide aluminum puck with a long solid cylindrical center that press fit into the heat sink. Also some polishing for an aesthetic finish. Sorry I didn’t take any pictures of the machining :confused:

I ended up using a 4s3p battery pack, with 3D printed parts. It uses common spring contacts and is held together by some M3 threaded rods.

I browsed Amazon for a cheap and large lens. You can find something like this with the search terms: 4” dome magnifier paperweight.

I used an Ultraboost Driver mounted to the bottom of the heat sink to boost from ~15v to 36v.

Here is the LED mounted on the heat sink. The lens is screwed on top of this part. This allows for some focus adjustment.

A fan was mounted underneath the bottom of the heat sink. The air is forced past the fins of the heat sink to provide the best cooling. Simulations in F360 say it can keep a 100W load under like 70C iirc.

Simple toggle switch for power

And here it is all put together

Also wondering how to get a tighter beam/ longer throw?

Update:
Here’s a quick video I took from my apartment rooftop. ~8k lumens in the video. Rated for 16klm though. Was just underpowered for my initial tests.

Standing 7.5ft away, the beam is ~36”, which I calculated to be a 22.5 degree beam.

And here it is against my wall so you can see it a little better

Also lined the inside with aluminum tape for a little extra reflectance

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Where are the pictures? I’m interested :slight_smile:

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Sorry, I'm new here. Thought I was saving a draft- didn't realize I had posted. Is now updated :)

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Nice!

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Cool. How are you measuring the output? Definitely could benefit from some diffusion. You can get cheap reflectors designed for those cree cxb leds that will smooth out that beam and make it more flashlighty. They’re on Aliexpress. You could modify a smooth flashlight reflector as well, but that’s tedious without the right tools.

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Cool, thanks for sharing. I agree with sirstinky that you should consider a reflector. The beam will be improved and be more efficient. With a lens like you have, more than half the light is not collected into the beam and is wasted.

As far as increasing the beam throw, that LED is good for producing a lot of light, but not for making a very intense beam. You could instead consider using multiple high power LEDs like cree XPL HI or luminous SFT40, though this would require a redesign of the front of the light.

What is the current output from your boost driver?

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That Hyperboost is pegged at around 3 Amps or around 80 watts max I think. Those cxb LEDs take 36 volts and 3.1-3.5 amps max.

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I have it set to ~2.5A which is the current used on the datasheet, although it should be able to go up to 3.2A with adequate cooling. I have a reflector meant for this LED, but it was designed to be used with a different led holder. I think I can get it to work with a few modifications. I will try it out.

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What you said about the Hyperboost is correct, but I am using the improved version of the Hyperboost, the Ultraboost, which is good up to 4A IIRC. As for lumen output, I don't have any tools to measure it. I was just referencing the datasheet graphs and what it "should" be producing.

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Nice. Those graphs with the data sheets are for bare LEDs and your output will be less…up to 15% with a reflector and maybe more with an optic or lens like you’re using. You need good cooling to keep that cxb cool at over 100 watts.

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Very cool

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Impressive :sunglasses: The best thing about using COB is that you can get sunlike spectrum. Like a BXRE-50S4001-C-74 with more diffuse lens would make it a perfect portable photography light.

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Very cool, thanks for sharing.

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Noice!

With a big-ass aspheric, you’d be able to project The Bat Signal into space, but at only 1/3 the lemons that the CXB produces. Nature of aspherics…

Focus in a reflector would be lousy, but would definitely be more efficient. Orange-peel would forgive a multitude of sins, though.

Just have fun with it in the meantime.