Is it cheaper to make a torch light?

As above, if I buy the required parts and put them together, will it be cheaper than brands like trustfire?

I have a few more questions which you guys can help.

1) Why can’t a AA battery be pushed out to 3Amp using a driver to light a XML U2 to 1000 lumen?
2) Why can’t we change the LED for Jacob A60 to U3 so that it become a superb thrower?
3) I tried to read up but except for flashlightwiki which has some basic tutorials, I cannot find any sites offering tutorials

Well, you have to buy at least the host.. unless you have a lathe. But I prefer building my own flashlights from parts anyways.

To power an XML at 3A you need about 10W. Given the voltage of an AA, you would have to draw about 10A from a single cell. That wont happen..

I think you need to add a little more detail and specifics in your posts. Many of your questions are just too open ended.

Building yourself can be fun and you can tailor it to your exact needs. If your need is specific then this is likely a cheaper option, however for something generic you’ll probably be able to buy off the shelf cheaper. Even if it comes down to shipping costs of buying lots of bits from many places.

As for your other questions:

1. Physics. As in you can’t break the laws of.
2. It’s the LED in the A60 that makes it a great thrower, changing the LED will obviously have a drastic affect on this. There are plenty of threads about throwers, but as a general rule you get more throw with a smaller LED vs a larger LED in the same size reflector. The higher the surface brightness of the LED the greater the throw. An XR-E (the LED in the A60) is very small and has a very high surface brightness, thus lots of throw. An XM-L is a large LED with a much lower surface brightness. So despite it’s higher lumen output, it simply isn’t as good for throw.

When thinking of lumens consider it a bit like torque with an engine. More is never a bad things, but high torque doesn’t always mean the most Bhp.

3. Keep reading BLF and posting questions, loads of great great info and hugely clever and knowledgeable members. :slight_smile:

To give you an idea, last night I assembled this:-

http://www.cnqualitygoods.com/goods.php?id=1488

I originally wanted to use this driver

http://www.intl-outdoor.com/4a-3mode-2745v-circuit-board-p-546.html

And I had this emitter, bought previously

http://www.intl-outdoor.com/cree-xml-u3-1c-led-14mm-mcpcb-p-606.html

Now, the build proved a little tricky, and of the two examples linked, one I’m saying I killed, although I’m not 100%, the second was nothing like the first three of these I had - UI all over the place and could only give 2a or so, 2 1/2 hrs wasted.

I ended up using this

http://www.intl-outdoor.com/amc71356-5mode-circuit-board-nanjg-105c-p-536.html

Adding two of these

http://www.intl-outdoor.com/amc7135-advanced-current-regulator-350ma-p-221.html

To give 2.8a because this is what I had available to prove the host, to be fair, I could have fitted this to achieve the same end

http://www.intl-outdoor.com/amc71358-5mode-circuit-board-nanjg-105c-304a-p-667.html

At the end of it though, I basically ended up with this

http://www.cnqualitygoods.com/goods.php?id=1454

And a grumpy Mrs because I spent all night messing about with a damm torch, and to cap it off, I’m just not that excited about it now its built. It’s a good host, with a nice beam and a good driver, just not exciting as I could just buy similar for about the same cash with shipping taken into account, if the first linked driver had panned out I’d be over the moon, if I’d ordered the right host, I’d have waited for the neutral xp-g2 to arrive, fitted the second driver with an extra chip and 3 mode, and been happy, I just find a 3 mode xm-l c8 w bit meh,now, I’ll probably swap in a neutral xm-l to improve my mood with it.

Then I’ll get an xp-g version to build the light I actually am excited about, as said above, total lumens doesn’t tell the whole story, its how they are applied and how the look that’s beginning to matter more to me. :wink:

in general, the only reasons to do it are for fun, or to build something that isn’t available for retail purchase…

which are pretty good reasons, in my book…

I agree whole heartedly, it is fun and generally satisfying, despite my grumpy mood, I just ended up with a light I didn’t need, rather than a light I really wanted. I’ll probably pick up some decent cells and an i2/i4 charger and gift it/sell it to an interested friend at cost.

That way, I have my money back, and still have the experience I’ve learnt from the build, a happy friend and I can move on.

Building a light you WANT is infinitely more satisfying than just buying another light imo, its just when you make cock ups in ordering/assembly that you can get jaded.

Energizer Ultimate Lithium can supply 3 amps constantly, I wondered the same thing recently and tried to look in to it.

Its something like Volts x Amps = Watts

Volts / Watts / Amps Converter

A 1.7v lithium AA battery at 3 amps can supply 5.1 watts to the LED
A 3.7v Li-Ion batterya at 3 amps can supply 11.1 watts to the LED

pretty sure the lithium AA would have some voltage sag at 3A

Plus, you’d be burning some of that current to get the vf up to 3.ish volts, the 3.7v cells don’t need to boost voltage, if anything at full charge it needs reducing, so your lithium primary doesn’t only have to send 3a to the emitter, it needs to run an inductor to boost the voltage to led operating levels, hence the many cheap 3aa/3aaa lights - 3 x 1.5 (series voltage) = 4.5v, convenient eh? :wink:

Also you’d want some runtime too. While it might not strictly be physically impossible to attain 1000 lumens from an XM-L via a 1xAA, it’s certainly impractical.

I think a XM-L at 10 watts is about 1000 lumens?

5.1 watts (a single energizer at 3A) might be about half that.

I don’t know anything about electronics so I could be way off but I did a little reading the other day before buying some 1 amp AA drivers to estimate the output.

A NiCd AA cell can give 10A — for about three minutes (since NiCd AAs never got much above 600mAh). A good NiMH AA cell can probably give 10A, though maybe not continuously — my SB800 flash briefly sucks at least 7 amps from Duraloops at the start of the charge cycle after a full-power flash (it’s a bit hard to tell, since the current steadily drops over the 3.5-second recharge).

An typical XML at 10W is around 800-900 lumens. Add in driver/wiring/switch/optics losses and you are lucky to get 600 lumens.

Long answer short NOOOOOOOOOOOOOOOOOOOOOOO. Don't let that stop you though as anything custom as a rule costs more but you end up with something you want and not something someone else thinks you need.