First time mod question.

[jhereg]

I have been thinking about modding a flashlight to use a 1W or 5W LED. The light I am looking at is one of the "Police" flashlights from ebay. It has a mediocre beam with the incan. bulb, but at least to my untrained eye should be a good flashlight to convert. It is a (2) 123 cell flashlight. The bulb is in a flat (9/16" thick x 3/4" diameter) aluminum holder that threads into the body of the flashlight. It appears the reflector is threaded into the inside of the bezel.

I want my first mod to be relatively easy. Can I direct drive a 1W or 5W LED w/ no other circuitry than a resistor to keep the current within specs? If that is the case I was thinking about putting the LED on the bulb holder as a heat sink & putting the appropriate optics in the bezel. (Assuming they will fit.) Is this a good idea? What would be a better idea? I am also thinking about the rechargeable Pila battery which would replace the 2 123 batteries. Would the same idea work with that battery? Thanks
Andy

 

[Steelwolf]

You may be disappointed with direct driving a 5W from 2xCR123. IIRC, the Vf of the 5W is just a little higher at 7V. But the 1W should be good, though a little wasteful. Main thing is to watch the heat buildup. Some modders have seriously overdriven their 1W but gotten away with it by having solid heatsinks.

 

[jhereg]

Ok. It sounds as if a 1W is my best choice. I obviously need a 1W LED. I have seen people talking about low dome, high dome & side emitters plus different types of optics. Run time is not my biggest concern, but it would be nice to know what I can expect.

1) Which LED should I look for? Where should I look to get info on the various LEDs?
2) What should I be able to expect for a run time?
3) Are there any good optics available that will fit in a 3/4" ID bezel?
4) What parts do I need to purchase? (LED, resistor(s), special adhesive, optics, etc.)
5) Probably most important, what should I be careful not to do?

 

[Steelwolf]

Lumileds website would be best for info. www.lumileds.com

Low dome gives a very wide beam. High dome gives a tighter beam and when coupled with appropriate optics, gives the best throw/beam for 1W. Side emitters were designed for use with reflectors. The beam is thrown mainly to the side so that it bounces off the reflector.

Arctic Alumina epoxy is the recommended adhesive to bond the LS to your heat sink. Alternatively, use mechanical fasteners (bolts, screws) and a heat transfer paste like Arctic Alumina. There is Arctic Silver made by the same guys, but that is not recommended as it is slightly conductive.

Beyond that, I'm afraid you need to wait for someone with more experience to answer. I'm still very much a beginner in this area.

 

[jhereg]

My current wild idea is one of the 3W luxeon stars that is supposed to be available soon & one of the fraen optics. (I know. They are both backordered/out of stock.) I'm not in a big hurry on this. I want to do it right. Have been reading a lot & trying to decide what is best. Where is a good source of Artic Alumina epoxy & paste?

Andy

 

[CM]

jhereg,

Wayne (dat2zip) has a toystore full of goodies for modders. He sells LED's, converter boards, arctic silver and other heat sink compounds, pretty much the whole gamut to make a *complete* flashlight. When you finish with your mods and are ready for something a bit more challenging, a McLux would be the next step in building your own light. I've built one myself and it was actually FUN! Wayne (Elektrolumens) also have a bunch of goodies though he mainly sells complete custom lights. Between these two sources, I'd say you've got 99% of what you will probably need. Just one more advice, hold on to your wallet /ubbthreads/images/graemlins/grin.gif

CM

 

[jhereg]

I've looked at the sandwich shop a little. I'm just getting to the point where I am starting to know what I would need. I'm asking questions to get a better idea. As a neophyte in this area I know my ideas are not always going to transfer well into a functioning flashlight. I prefer to keep the smoke in my devices as much as possible. Thanks for the info.

Andy

 

[AilSnail]

andy: I think the fren lp and nx05 is around 22mm OD. They can be turned (filed?) down. There is about a millimeter rim on the nx05 that can be removed without compromising optical characteristics. Refer to among others tvodrd mini cr2 and mini 123 lights as well as dspeck's firefly for examples of cutdown and turned down optics.

Is it possible the stock reflector can be used?

Carley sells .75 reflectors with and without texturing ("orange peel"). For an example with a 5w HD see here .

 

[Mark_Larson]

www.svc.com is a good place for AS, AA and the like. Plain old Silicon Heatsink grease from Radio Shack would also do in a pinch.

 

[jhereg]

It is possible the stock reflector can be used. I can always enlarge the hole in the reflector if necessary. I have also been looking at a Surefire P60 I have sitting next to my computer. I could turn the outside down on a lathe or chuck it into a drill press & touch a file to the outside to make it fit. I think that would give me a much better reflector. I have verified a Surefire P60 will work if I can make it fit in the bezel. I would like it if my modified light was useful, but mostly it is a chance for me to learn something new.