A Perfect Dedome?

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Slewflash
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Tom E wrote:
I’ve done 3 Small Sun T08’s, de-domed in gas. They all go from 95-100 kcd to 200-210 kcd.

Small Sun T08s don’t start at 100kcd, stock they’re closer to 50kcd.

Slewflash 

Manual Man
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Slewflash wrote:
Tom E wrote:
I’ve done 3 Small Sun T08’s, de-domed in gas. They all go from 95-100 kcd to 200-210 kcd.

Small Sun T08s don’t start at 100kcd, stock they’re closer to 50kcd.

Thought it sounded to good to be true, ahh well you saved me $27.

AlexGT
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Did you really get a UV emitter by removing the phosphor layer? I thought the tint you get was blue, can you make things fluorescence like a passport or driver license?

comfychair wrote:

I finally killed one, but the gas didn’t do it. I had the bright idea to try rinsing in acetone instead of iso and even though it was just a quick dunk the phosphor went goofy and peeled up at the corners. LED still works, I managed to get all the phosphor off and now have a dangerously bright XML2 T6 UV emitter on a 16mm Sinkpad. Steve

So, don’t do what I did. Rinse in iso only.

tallboybass
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This raises the question…“why do they put domes on the LEDs in the first place?”

Tom E
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Manual Man wrote:
Slewflash wrote:
Tom E wrote:
I've done 3 Small Sun T08's, de-domed in gas. They all go from 95-100 kcd to 200-210 kcd.
Small Sun T08s don't start at 100kcd, stock they're closer to 50kcd.
Thought it sounded to good to be true, ahh well you saved me $27.

Ooops! My mod'ed T08's start at  95 - 100 kcd. I meant fully mod'ed with dome (4.2A nanjg, XM-L2/SinkPAD, copper, UCL/p lens), then after de-doming this highly mod'ed light... Sorry I didn't make that clear. These are all true numbers, verified after the de-doming by another BLF'er on his well published throw measurements (http://budgetlightforum.com/node/21112), but only after the modding Smile.

manxbuggy1
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tallboybass wrote:
Well everyone seems quite happy with their lightmalls.com C8’s, that’s for sure!

I feel bad that my first modding of a flashlight went south, but it must be a sign…gonna try not to do that anymore (actually, now that I think about it, my first flashlight modding was grinding the keychain nub off an ITP A3 so it’ll tailstand! Wink ).

Yeah I ground mine off too and it still wont tail stand very well so like you no mods for me either.

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manxbuggy1 wrote:

Yeah I ground mine off too and it still wont tail stand very well so like you no mods for me either.


LOL!! Big Smile

Well, my A3 DOES tailstand at least! (I used wire cutters and sandpaper) …then blackened with a Sharpie…some real high tech stuff, I’m mighty proud… Glasses

Slewflash
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Tom E wrote:

Manual Man wrote:
Slewflash wrote:
Tom E wrote:
I’ve done 3 Small Sun T08’s, de-domed in gas. They all go from 95-100 kcd to 200-210 kcd.
Small Sun T08s don’t start at 100kcd, stock they’re closer to 50kcd.
Thought it sounded to good to be true, ahh well you saved me $27.

Ooops! My mod’ed T08’s start at  95 – 100 kcd. I meant fully mod’ed with dome (4.2A nanjg, XM-L2/SinkPAD, copper, UCL/p lens), then after de-doming this highly mod’ed light… Sorry I didn’t make that clear. These are all true numbers, verified after the de-doming by another BLF’er on his well published throw measurements (http://budgetlightforum.com/node/21112), but only after the modding Smile.

Makes much more sense now!

Slewflash 

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AlexGT wrote:
Did you really get a UV emitter by removing the phosphor layer? I thought the tint you get was blue, can you make things fluorescence like a passport or driver license?

I have an actual UV light (but only 3x 3mm LEDs) for A/C leak detection, and this one with phosphor scraped off looks the same, except about 300 times brighter. Maybe the tint is a little more blue than purple but it's still putting out TONS in the UV range. Even 'blue' LEDs have a lot of UV in them and glowy stuff will glow enough to be noticeable, but this one is fierce. I'm not using it again until I have some proper protective glasses, even though I of course never looked directly at the emitter just looking at things it was pointed at left me with purple shadows in my vision for several hours afterwards.

Unlike the original XML, XML2 isn't damaged by scraping the top of the die, it's just a flat featureless slab of ceramic(?) with no traces to be damaged. Doing the same to a XML would have killed it.

texaspyro
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http://en.wikipedia.org/wiki/High-energy_visible_light#Blue-light_hazard

Also, your eyes are not very sensitive to blue light and your iris won’t close down… you get hit with a LOT more light than you think…

Tom E
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Interesting ideas... I'll check if I got mineral or baby oil and give it a go. Got at least 20 of XML T6's laying around now, so good for experimentation.

tallboybass
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I got a couple of Defiant 2AA lights @ Home Depot last night. Is there any point in dedoming? It would throw better and the tint would warm up, right? I believe it’s an XB-D emitter…? It would be a cheap experiment anyway…let me know what you think!!

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Anyone?

relic38
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I can’t say I’d recommend 2×14500 in a 2xAA light. Sounds bad for the emitter to me.
As for dedoming, I’ve never tried one of these tiny emitters. I have an XB-D kicking around somewhere.

Welcome the night.

My Reviews   My Mods    http://budgetlightforum.com/search?

tallboybass
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I like mine…for what they are. Used one as a bike light tonight. It was ok but the batteries rattled a bit. Cat Eyes…you’re a ‘bad boy’…taking those back after abusing them with 14500s!! Wink

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Kind of blurry, but the best I can do with my old DSLR. It doesn’t do well over 400 ISO and I need a macro lens.

Here’s a picture of a dedomed stock XML2 from a TN31 (by TomE himself).

Slewflash 

Fritz t. Cat
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One of you hotrodders who like to put in 3A drivers might try filling the space around the emitter with some liquid like mineral oil or ideally freon. You can’t use anything with water in it because it hydrolyzes at around 3V. Even a high boiling liquid will expand enough when hot to circulate and carry away heat. A reflector light or a non-zooming planoconvex aspheric should work perfectly well full of oil from front to back. It may even cut down internal reflections.
One of the most beautiful things I have ever seen was a running Cray II computer. It sat in an aquarium full of freon, and little streams of tiny bubbles were coming up from the components.
I expect manufacturers will do something like that at some point when they get the intensity up to where heat is the main limitation, maybe by filling a hollow dome with fluid.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Tom E
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Heat's always an issue, even with doctor's illuminated head gear when they are doing 4+ hour operations - this is relatively low amps, but strapped to someone's head it's not pleasant when it warms up. Weight is an issue too, so guess it depends on how much liquid. I know of at least one crazy intense bike light custom built that used water, I believe, for cooling - I think the emitters were mounted on an aluminum plate, then the cooling system acted on the aluminum plate from the other side.

 3 amps is still stock to me - custom, we are talking 3.5A on up, maybe up to 5 amps in regular builds for single emitters.

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I attempted a de-dome of an XM-L U2 that was installed in a small light, it’s direct drive with no driver so I dunked the entire head in gasoline. But, with the wife and kid wanting to go to the lake I got in a hurry. I removed the dome at 4 hours and broke 2 of 3 wires.

DBC_July 01, 2013_125729

I figured, with nothing to lose, why not try this weird black liquid solder from Radio Shack that I bought mistakenly as glue? It’s electrically conductive, so why not?

DBC_July 01, 2013_130948

And with that, I saved a de-dome! Smile

DBC_July 01, 2013_143531

Looks awesome too in this really small light! Smile

HF Cu XM-L U2 De-domed 11L

Mind you, I’m not experienced at this kind of stuff. So if I can do it….

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Fritz t. Cat wrote:
One of you hotrodders who like to put in 3A drivers might try filling the space around the emitter with some liquid like mineral oil or ideally freon. You can’t use anything with water in it because it hydrolyzes at around 3V. Even a high boiling liquid will expand enough when hot to circulate and carry away heat. A reflector light or a non-zooming planoconvex aspheric should work perfectly well full of oil from front to back. It may even cut down internal reflections. One of the most beautiful things I have ever seen was a running Cray II computer. It sat in an aquarium full of freon, and little streams of tiny bubbles were coming up from the components. I expect manufacturers will do something like that at some point when they get the intensity up to where heat is the main limitation, maybe by filling a hollow dome with fluid.

Water-cooled flashlights :)! They do that nowadays with PCs/CPUs, with heatsink/contact piece contacting the CPU and then a pump that moves the fluid to another part that has a radiator and fan(s).

Fritz t. Cat
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I suppose he had to keep the water away from the contacts. Water is a great coolant in the temperature range in which it is liquid, but not for bare electric wires. Some oil is a better insulator than air, and there are low viscosity and low boiling point fluids that are good insulators too. There might be something oil would dissolve, like the insulation on the wires or glue.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

gords1001
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thank you tom for this thread, I’ll be trying my own dedomes this month, I should probably do a dead xm-l first just to have a look see, but…..well……my atttempts will likely be on xm-l2 u2’s…..hope I don’t mess it up.

I’m aiming for 200+kcd out of a convoy l2, I have a hs1010 inbound too so I can join in on verifying results, there are also 5a two cell drivers and xp-g2’s to throw into the mix. lets say I really want to hit the 1/4 lumen at 1k mark…..

expect a few questions in the next few weeks. for now, I’m eating a lot of feta cheese – it comes in a perfect little bath, complete with basket for extracting emitters :bigsmile:

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For 9.4A in a MagLight?

Tom E
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Hi Gords - just did my first de-domed HD2010 and got 200 kcd - XM-L2 U2 1A/Noctigon, 4.2A Nanjg, UCL/p lens, 3 copper discs added to the pill, and running a KK ICR 4000. Think I got maybe 203 kcd on a KK ICR 4200, little better but not even fully fresh charged - Ric sells them. To get the most out of a HD2010, you have to loosen the pill to get the emitter further out - made a big difference in throw and lumens. I used this pricey CircuitWorks CW7100 stuff that's a conductive thermal grease on the pill threads, this: http://www.all-spec.com/products/CW7100.html. Also, I sanded the backside of the reflector to free just a little more space for the wires.

Also, I just de-domed 2 XP-E2's for the first time - one went into this light: FT-ultrafire-zb-006. It's a cheap little zoomie, but used a 2.8A Nanjg, de-domed XP-E2 on a SinkPAD and got 60 kcd out of it, and it's not even focused well. I may play a little more with it and see. I got 2 copper discs in there somehow - this light has no weight to it, no heat sinking, hollow pill, etc., about the size of a convoy S3 or S4 but fraction of the weight. It gets pretty blazin hot in like 1 minute, but still puts out a lot of light in flood mode. I downloaded a 2 mode setup of Hi and a 15% lo.

Fritz t. Cat
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I don’t suppose the stuff I use to fix rear window defrosters would be conductive enough. I once designed a shape that was tested for radar cross section coated with paint made of silver metal.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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If the space between the emitter and front window (lens) were full of oil with similar refractive index to the dome, the dome would have little effect on the optics, so one would get a smaller spot without taking it off. The oil would help cool but not as much as with the dome off. Then there is the long term effect of the oil on the O-rings.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

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But wouldn’t the oil trash the beam? I mean, any liquid is going to diffuse light isn’t it? And while it might absorb some heat, it can’t conduct the heat away so it would soon become heat saturated and lose any cooling capacity. Would it not? The only way I can see for any liquid to have a cooling effect is if it is transferred to a location that can absorb and wick away the heat from said liquid, then the liquid can be returned for more heat absorption, just like a radiator in a car. An oil filled heater is supposedly energy efficient because once the electricity is expelled to heat the oil, the oil retains that heat for an effective period of time and radiates it slowly to the surrounding air, so once heated up the amount of electricity needed to keep it warm is minimal.

So what good would it do to have the reflector full of oil? Even in a fairly large light, that area is of sufficiently small capacity to allow rapid heat saturation, what would then remove this heat from the oil?

I guess it’s pretty obvious I don’t understand what you’re proposing.

Makes more sense to me to have a fan pushing air behind the heat-sink and out of the light. As has been said, once the heat-sink warms sufficiently the disparity between it and the ambient temperature is sufficient to pull heat off the copper or aluminum (preferably copper) to keep the emitter cool enough to be efficiently run for prolonged periods of time in an over-driven capacity.

I recently made a copper and brass light for O-L’s challenge. When working the metal (by hand, or hand held grinding with a dremel tool) the heat would fairly quickly get beyond hand holding levels. Blowing on it, for just a matter of seconds, immediately reduced the part so I could continue working. Didn’t take much moving air to pull the heat off of the copper or brass sufficient to allow handholding. So it wouldn’t take much air flow to keep the heat-sink saturation level in the efficient range of the emitter.

Am I way off base? Work copper for a couple of hours with it held in your bare hand, then tell me I’m wrong. And yes, I’m considering the level of heat an emitter can bring to the equation, but so can a cut-off wheel, or a carbide rotary bit. If a piece of copper is clamped in vise-grips and worked this way, it will get hot enough to melt things it comes in contact with (dropped a couple of parts, found out the hard way)

Not trying to be argumentative here, just trying to understand.

Fritz t. Cat
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The mineral oil bottle I have in the cupboard for my skin is white, but previous ones have been clear enough to see clearly through bottle and oil. Slight clouding wouldn’t hurt much. The idea is that the oil picks up heat from the led, rises and carries the heat to the case. The case gets hot even quicker, but the led itself stays cooler. The oil is as poor a heat conductor as the plastic, but it swells which makes it rise and carry the heat to the metal case, where it doesn’t hurt anything till it gets so hot it burns your hand.
No, the overall efficiency of electric heaters is all exactly the same, unless they are heat pumps. Heat pump heaters are air conditioners working backward. They cool the outdoors and bring that heat inside. Two of the laws of thermodynamics say that energy is conserved and that it tends to end up as heat. So any electrical appliance has the same heating efficiency as any other, unless it moves some form of energy in or out. That is why the same led light bulbs that save electricity directly are the ones that save on air conditioning.
After a while the outside of the light would be the same temperature as if it were full of air, but the heat would get out of the led quicker so it would be cooler.
Yes forced air would work too. So would making holes in it, but that wouldn’t be good in the rain.
I am not sure how much cooling the air around the led in a normal flashlight provides. It must circulate by convection, but its density is so low that it has to be moving pretty well to carry much heat. The oil would circulate similarly to the air but take more heat with it.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

texaspyro
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texaspyro wrote:
Already done here: http://www.switchlightingco.com/

Yes. Thanks.

Added: It says “Think of a lava lamp; this works basically the same way, ….”.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

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