Why all the headlamps output are so low?

[hopkins]

That Ultrafire headlamp pic looks a lot like the Smith&Wesson 3aaa Cree headlamp I bought at Big5 Sporting Goods last month.

Don't think it can dump heat any better either with its all plastic body.

I almost suspect it'll melt if left on with fresh lithiums or NimH cells. The reason I installed another switch and resistor for a low mode in mine.

 

[NickBose]

It would be at least 4 times brighter, but don't expect the quality to be much.

Which one is 4 times brighter and why do you think so?

 

[Marduke]

Which one is 4 times brighter and why do you think so?

The Cree would whoop a silly 5mm showerhead headlamp. However, like I said, the quality on either is probably pretty crappy and not worth the money. For $25, you can get a much nicer Coleman headlamp at WalMart.

 

[fluke]

Elektrolumens Minimak 14500 with Nite-ize headband - SSC-P4, Fraen optic, 14500, cutdown minim@g.

The torch in the OP should also fit the Nite-ize headband. The Fenix L2T/D and P2/3D are fatter but will go into the loop with some pushing. It is preferable to use a 2 cell light as the hot parts are further away from the loop and your head.

What size is the head band ???
Not all heads are the same

 

[Flashfirstask?later]

What size is the head band ???
Not all heads are the same

They are adjustable (velcro) but it certainly is not long enough for say a safety hardhat. The one thing I do not like about this is the side spill can get into what ever eye it is by if it is not forward enough.

For Canadians, the cheapest store I have seen them is the Mountain Equipment Co-op sores (www.mec.ca) at $4.25 and they also have the Nite Ize Stretch Lite Holster for $6.50 (clearing out AA size at $5.00) as it can be used at horizontal at waist level.

 

[NickBose]

The Cree would whoop a silly 5mm showerhead headlamp. However, like I said, the quality on either is probably pretty crappy and not worth the money. For $25, you can get a much nicer Coleman headlamp at WalMart.

I doubt that the LEDs in the rechargeable 6-LED lamp are normal 5mm LED. There are 2 reviews on DX page and both said it's very bright, one estimated it to be around 80 lumens. It must not be the case if it's 6 5-mm LEDs.

 

[Marduke]

5mm's can only be so bright. Definitely not 80 lumens for 6 of them.

 

[t3h]

http://www.dealextreme.com/details.dx/sku.15688

That's the more expensive of the two most recent ones. It features 6 LEDs, which are actually red, green and blue, not used for the white. The white is a P4. Would a Q5 or R2 just be a drop-in swap (well, with some soldering)?

The description says it's 5 mode - taking away 3 for red, green and blue must mean it's got a low mode? Or is the 5th mode something to do with the red *thing* on the back?

 

[TorchBoy]

http://www.dealextreme.com/details.dx/sku.15688

That's the more expensive of the two most recent ones.

I checked it just half an hour ago. There are more products already! :tinfoil:

 

[hopkins]

I read and reread the Ultrafire headlamps function description and it 'seems'
to use those 5mm red-green-blue LEDs with 4 legs each. So all 6 5mm LEDs will be powered at the same time but emitting
either red, green, or blue depending on which leg is getting the juice.
The Cree will have one mode only -High!
And a blinking 5mm LED 'red' mode.
So thats the 5 modes.

Suspect thats a non powered reflector on that beautifully designed battery pack. I'd be very envious if I was following this headlamp on a trail knowing
how dull and ordinary the Myo battery pack looked on my head.

.......and it looks to be an enclosed plastic headpiece without any ability to dump 130lumens worth of heat. Or is that black metal?

This lamp is unusual to say the least.

 

[TorchBoy]

There are no electrical contacts to the battery cover, and it looks like plastic to me.

 

[hopkins]

Yup its plastic. Too bad. Think it needs a separate switch for the Cree.
Wonder how well the Cree is heat sinked inside and if it can be opened
for some clever modifications.

 

[TorchBoy]

Looks like a couple of screw holes at the top of the back panel, so I'm guessing yes.

 

[degarb]

To me, as a work task light, you need 8-10 hour run time. Currently 3 AA have about 9 watt hour recharegables. That mean 1 watt max for a full day and 1.5 watt allowable on 6 hour days.

10 minutes down time for a change (inviting breaks for workers): 1 AA format every 2 hour or 40 minutes a day. Roughly, 1 hour in every 10, or 10 hours per 100 or 100 hours per 1000 hour large job. Thus, the push for full day duration.

A rebel 100 or r2, though please. With either a variable pot or many lower settings. Then one can get 13 or 14 hours with over 100 lumens when needed.

I usually mod the 3 AAA format to 3 AA. I found, so far,1 AA in front and 2 AA in rear of band, is best balance of life and comfort. I suppose 2 or 3 18650's or 6 cr 123a packs, would be better. But this seems a like a big jump, and not sure of practicallity for a small fleet of lights.

 

[TorchBoy]

To me, as a work task light, you need 8-10 hour run time. Currently 3 AA have about 9 watt hour recharegables. That mean 1 watt max for a full day and 1.5 watt allowable on 6 hour days.

Ever thought of changing your battery during lunch?

I'm really not sure what you're trying to say during your second paragraph. Changing a battery doesn't use up one tenth of a day.

Since you're modding, you could mod to six AA cells and use a suitable buck driver, but you might find people are happier taking a few seconds to change three cells half way through the day than wearing six the whole day. I guess it comes down to whether one watt is enough light to do the job effectively.

 

[ahorton]

For a few months I've been reading through these forums but this thread has inspired me to post something.

My interest in lights comes purely from rogaining (24 hr orienteering) and I started making my own headtorches after being frustrated by what is currently on the market.

I wanted a light that had 2 settings,
1 - very low power and broad to look at maps and see my feet (no more than 5m vision.
2 - a very high and focused beam to find controls (300x300mm pieces of corrugated plastic) and work out subtle variations in the landscape.

I really have no need for anything in between.

So I researched and discovered high powered leds, cree and the aspheric lens.

I'm up to my 5th generation of lights but the general theme has been:

- Chunk of cpu or windowframe aluminium on the forehead.
- Cree Q5 or R2 behind an aspheric (30-50mm)
- 4 5mm leds for low level
- 6 nimh (AA on the head or C in the backpack) or 2 lipo
- 3021 buckpuck for the Cree
- Small sliding switch to send power to 5mm leds or the cree.

Initially I had the aim of sending a thin beam of light as far as possible. Then I realised that at 350m, I can't see a 300mm control in broad daylight even though the torch could shine that far. So now I'm aiming for maximum beam width at 200m.


Somewhere in the mail are new lenses, 40 AMC7135s, 2 MCEs and other bits and pieces.

Thanks for this forum. I have learnt a lot and gotten hooked.

 

[TorchBoy]

:welcome: ahorton! Your lights sound great. Do start a thread sometime about them, preferably with pics.

 

[hopkins]

speaking of aluminum heat sinks in headlamps: I finally added a strip
of aluminum metal to the Smith & Wesson Cree 3AAA headlamp I bought
at Big5 Sporting Goods. After 5 minutes its very hot to the touch so at
least its taking heat outside the lamp body.

I just cut a slot in the body so the aluminum strip contacts the underside of the Cree LED assembly inside; helped by some thermal paste. Pictures:
note: sometimes you have to go back and click on these links again for the pic to appear...:thinking:
http://www.postimage.org/image.php?v=gx17Yt_0
http://www.postimage.org/image.php?v=aV1jnao0
http://www.postimage.org/image.php?v=aV1jncT9
http://www.postimage.org/image.php?v=aV1jnmRJ

 

[ahorton]

Many times I have considered cutting the back off a bought headtorch and increasing the heatsink that way. Every time I consider it I end up deciding to just make the whole head unit out of aluminium.

I'm really keen to hear how long you think it's safe to run that thing at high power at a particular ambient temperature.

 

[hopkins]

My guess is without any wind at room temp that 10 minutes is a safe runtime.
But outdoors, at night, (duh!) with any breeze it would be ok for any runtime.

I ran it for 1hr 40minutes till it started to dim (aaa NimH batteries nearly empty
at 400mA beginning drain current). I confess to starting a little fan blowing on the heatsink
stub after 15 minutes as it worried me how hot it was. The fan cooled it
down (LED still on full blast) within 5 minutes till it felt cool to the touch for the
remaining runtime.

There are a lot of documents to be viewed on the web about heat sinks.
Seems many people have devoted serious thought to heat and its mostly
in easy to understand form. Do a search for "heat sink".