Help me defeat the nay sayers! (LED divelight)

nwbrewer

Newly Enlightened
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Jan 14, 2008
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Seattle area
Greetings CPF community!


After endless threads on SCUBA diving boards about how much better HID divelights are than LED's, I have set out to prove them wrong, and that's where I need your help!

I've come here seeking help for different kind of maglite mod, specifically one with a detached battery canister, so my battery volume isn't as important as when dealing with ordinary maglight mods. Here's what I have done so far -

IMG_2429.jpg


Powered by 5 NiMh AA batteries, using a Terralux drop in LED. TLE-6EX and the standard mag reflector. I have a 2 amp reed switch to turn the light on/off, with the magnet in the handle.

While I like this setup, it's just not bright enough to quiet the Nay sayers with their HID's.

So here's what I'm looking for -
Bright (I'm hoping to match a 21watt Brightstar HID)
Nice white light.
Tightly focused beam for signalling
I'd like to stay in the Maglite head as I know I can seal it, and I already have it.
I'd prefer to stay with the battery setup I have using NiMh AA's, but I can add more, going up to 14.4V.
It has to have about 1/8" clearance between the Reflectors and a standard mag lense, as I use a stepped lense that sits down into to head to hold the o-ring that seals it up and makes it waterproof.


What I'm thinking -
One of ModaMag's D cell heat sinks with 3 Cree XRE emitters. Does this sound like a good setup, or is there something better? Specifically which emitters as I know there are different Bin codes and such.

What works best, the little lexan lenses or reflectors?
What to use for a driving circuit?
Anything I'm missing?

I'm kind of new to this, hopefully I'm not asking too many stupid questions.
Thanks for any help you all can offer.

Jake
 
Q5 bin Cree XR-E's are probably about the best bang for the buck bright LED available right now. Tint choice is always a personal thing, and seems to have some randomness to it. Sometimes people notice big differences in tints for LEDs that have the same tint code. And some people prefer the warmer tints but personally, I tend to like the ones that have a little of the blue in them that others just hate. It's a matter of taste.

Personally, all my multi-cree builds have been using the Shark step-up driver from the Sandwich Shoppe. The Shark likes battery voltage to be at least 1/2 of LED voltage so 5 cells should drive 3 LEDs just fine. Personally, I have done 4 LEDS with a 5 cell Magcharger pack with no problems in testing. But I've never had a light stay in this combination for the long term so can't testify to it's long term performance. The Shoppe also has step-down drivers. Although I've never used them, TaskLED is another source that many people use for drivers.

Lately, I've been using Download's Multi-sink due to it's versatility, but if you need extra clearance for the lens, you should probably stick with ModaMag's PXR19 heatsink, also available from the Shoppe, since it sits lower in the head.

The McR19-XR reflectors are the best I've used with the Cree LEDs, but they are pricey and usually held in place with the lens. If you want the reflector to stay on the LED without contacting the front lens, you may want to consider the Fraen faceted reflectors. They are plastic, produce a fairly tight smooth beam, and clip firmly to the metal ring around the Cree LED. I got mine from Cutter Electronics. They also have a variety of optics with varying beam profiles available.
 
yes, sounds good.
there is an optic for the cree that is very tight spotty (reflectors often have smaller spots than optics).
it is very cheap sold a KAI domain, for the price its worth a try even if you use reflectors. you have to get the holders too with cree, without them the optics are impossible to place.

with optics ALL of the light gets culminated
with reflectors only the light that HITS the reflector gets culminated, the light that does not hit the reflector AND gets Past the reflector, just goes willy nilly all over the place :)

optics arent usually AS spotty as a reflector can be
a reflector can have a tighter spot, but has a lot of Spill.

so depending on the type of light you want, will depend on if you use reflectors or optics. if it is important to have a tight spot beam, then get a great reflector
if splashing a beam around you in some turbid water, lighting up everything in your Face , is not desired, but tight pencil point beam is not needed, then an optic would be better.

that is my assessment, its hard to see the SPILL light in the beamshot pictures that you see here. optics have come a long way.
a HID does not have so much spill as a LED that most of the light is aimed OUT of the reflector, the hid bulb thing is more side slamming a reflector , so more of a Hid beam does not go all over the place as spill.

there are other optics too, a Aspheric lens, or fresnel lens can take a single point of light and project it with actual optical magnification type stuff. for a very very tight beam, and is focusable, so you can potentially wide it out too.
that also would be great for diving, but would add in a level of sealing that might make the project more complex.
aspherics and fresnels will not work with multiple seperated light emitting items, you must really have a single smaller source of light. (means your stuck with 1)

modamag tri-star holders and cree with an optics should work good., and you CAN assemble this stuff so you can get and test BOTH, there are reflectors the same height As optics, so you can switch and test both.

as a side note: there are some wild cool designs done where a LED is set to side shoot a reflector, teralux has one with 2 side shooting, and a expert here , made a tri-cree on a specialised heat sinc that was amasing, 3 crees on a triangular post from the heat sink, all slamming direct into a reflector. the teralux was weak at best to todays standads, and i dont think the tri-cree was available to sell to everyone, but they both changed the way things are done in a reflector.

finnaly found it, they Upgraded it :-( oh oh
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=1488
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=1603
 
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A waterproofed Multi LED light would probably be your best bet for output.

3 Cree XR-E Q5s driven at 1 amp each would give you around 690 lumen at the emitter, but a 21 watt HID should be around 1200-2000 lumen. You might need more LEDs.

I would recommend 7 Q5 LEDs each driven at 1 amp. Around 1600 lumen at the LED. Something like this except waterproof.

:welcome:
 
I have a very similar task in front of me. I maintain and fly a fleet of mini/micro rovs. We use halogen bulbs that run on 150vdc, they suck in every way. Get too hot out of the water, condense water and short out if they change temps fast. Leak. I hate them. I've been saying for so long that I can build an led light that I can waterproof, run off 12v or less, throw farther and work better. So now the powers that be have charged me with the task. Considering that I can build something for under 50 bucks and we're currently spending about 500 bucks a piece for the halogens, I believe there is a good profit margin for me in there somewhere in the middle. So I want to do it right.

I'm considering more of a surefire base. Mine don't have to go down beyond 1000 ft so I can pot a nitrolon light and call it good I think. I'll probably try it out with some of my cheaper dropins and g2's, then move up to some 12v led dropins. Maybe some malkoff p60's and drop the voltage. I dunno yet. I will probably fab up some alum/glass 2-3" heads in the machine shop to get some better throw outa em. I've been playing with aspheric lenses lately and love the throw, but I dunno how well they'll work under water, particularly in low-vis situations. Mine will be variable brightness too, so I don't think the vis will be too much of a problem. We shall see.

I think if I were to try this with maglites I'd try to use some aspheric lenses, I've had great luck with led's and those. I have a couple that'll throw 1000 ft. :D Might be something to look into for ya.

Good luck, nice to know i'm not the only subsea flashaholic around ;)

g
 
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I'm considering more of a surefire base. Mine don't have to go down beyond 1000 ft so I can pot a nitrolon light and call it good I think. I'll probably try it out with some of my cheaper dropins and g2's, then move up to some 12v led dropins. Maybe some malkoff p60's and drop the voltage. I dunno yet. I will probably fab up some alum/glass 2-3" heads in the machine shop to get some better throw outa em. I've been playing with aspheric lenses lately and love the throw, but I dunno how well they'll work under water, particularly in low-vis situations. Mine will be variable brightness too, so I don't think the vis will be too much of a problem. We shall see.

I think if I were to try this with maglites I'd try to use some aspheric lenses, I've had great luck with led's and those. I have a couple that'll throw 1000 ft. :D Might be something to look into for ya.
g

If they have to be good for 1000ft, i doubt any standard mag or surefire would be able to withstand the pressures and be leak proof at those depths. we are talking 30Bar/440psi pressures which is quite substantial. If you have access to a machine shop, why not build a proper divelight body from scratch.
I built something similar here http://www.candlepowerforums.com/vb/showthread.php?t=117739 which might be of some inspiration
Just my 2c
 
If they have to be good for 1000ft, i doubt any standard mag or surefire would be able to withstand the pressures and be leak proof at those depths. we are talking 30Bar/440psi pressures which is quite substantial. If you have access to a machine shop, why not build a proper divelight body from scratch.
I built something similar here http://www.candlepowerforums.com/vb/showthread.php?t=117739 which might be of some inspiration
Just my 2c


I potted two cr123's into a g2 and sent it down with the rov last trip out in the gulf. It went down to 550ft for around 3 hours (not on) and when it came back up had no water intrusion and still worked like a charm. That's with a dx cree dropin. I was surprised, that's what got me thinking about using em full time. I can build something out of metal stock from scratch but it'd cost me way more than a 36 dollar g2 with a 10 dollar dropin ;)

g

edit: oh man that steroid light is awesome. I may just have to spend some time soon in the machine shop afterall. woot

g
 
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Well i suppose you would have them wired directly to the ROV powerplant rather than using batteries so you basically just have to build a head which does not require a lot of material or a lot of machine work. you could still use the dropin but it would be housed in a much safer body with a thicker glass. Im quite sure that it will end up being a lot cheaper and more reliable in the long run.
I would suggest using brass rather than aluminum unless you have access to anodizing.
P.M me if you want some design ideas and/or discuss further.
 
Yep, most of the lights we have now are stainless or anodized. I really want to get away from stainless, my 70lb fish has most recently been "upgraded" to almost 110 lbs. bleah. Most of the reason I like the nitrolon idea. Haven't had any time this week to mess around in the shop, hopefully soon. We need a subsea flashaholics forum haha


g
 
here is my light I built.
http://www.candlepowerforums.com/vb/showthread.php?t=180188

After my recent dive in Truk Lagoon, Micronesia i found it brighter than any dive light any one had.I would compare it to 35 to 45 watt halogen.

I went to a depth of 140' and had no real problems.

The only problem to speak of was the switches I choose could have been better as the rubber boots did break...but that did not stop the light from working.

I did like the variable brightness for different conditions and I did have a opaque cover to disperse light for better photography
 
One hic-up.......I blew out one glass lense because my reflectors were not sitting perfectly flat against the glass for support......But amazing thing...did not have it lit at the time so I just kept it off till I surfaced.

Then I rinsed it out...used automotive sand paper and water and ground the reflectors flat.

But something I found out about the arctic epoxy.....salt water causes it to separate from the components........the epoxy actually became rubber like...peeled away....
 
But something I found out about the arctic epoxy.....salt water causes it to separate from the components........the epoxy actually became rubber like...peeled away....

That soaking AA epoxy in salt water will soften it, I believe, is a very valuable piece of information :twothumbs
 
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