Cheap Homemade LED Torch (full Build)

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Introduction: Cheap Homemade LED Torch (full Build)

About: I'm an experimentalist, a scientist and I have a tendency to do things just for the sake of doing them, or to find out what they're like. I love life, show me something I can feel good about. I've got an ...

A cheap source of LEDs
A full torch / flashlight

Step 1: LEDs

I found a pack of six gas-lighters with built-in LED lights for a pound.

Dismantling these was fairly easy, as shown in the pictures, it's not too dissimilar to 'breaking'

If you've got LEDs already, skip this.

Step 2: LED Assembly

Wire all of the LEDs together.

I've pushed the +ve electrodes through a small piece of insulation, cut from some heavy mains cable, like an elastic band this holds the electrodes together.
Also looped around the electrodes is a bit of thick copper wire.
The (yellow) insulation holds the electrodes in place while solder is applied, joining them to the copper wire.
A quick bit of soldering and you're done.

Next wire all the -ve electrodes together (see pictures). I've used individual copper strands from mains-cable, soldered and twisted.
Take a strand of copper (extracted e.g. from some mains-cable), tin it, tin the LED electrode and solder.
When you've done all six, twist them together, around the the outside of the central electrodes, to form a single -ve

Spend a bit of time getting the LEDs correctly aligned here. You can tweak and nudge the LEDs so that they form a nice alignment pointing in the same direction, but it takes a bit of time. Once you've got this to your satisfaction, it's time to move on to the next step

Step 3: Casting the Head

I'm encasing the unit in resin, using a handy mould I found.

Holes were drilled for the electrical connections, and I tried to seal up with Blu-tack (worked OK, but did leak a bit).

Regular resin for glass-fibre was poured in, and left to set.
The mould was cut away, but I could probably have forced it out.

Last (on this step) I've soldered a switch onto one wire, and a battery-contact onto the other. Both of these came from another horribly-cheap LED torch, which never worked (freebie)

Please see pictures, they are annotated

Step 4: The Rest

Roll a tube from paper around some AA cells.
I've coated this with resin, but tape would be just fine.

For the other battery contact I've got some wire through a plastic disc, screwed it up a bit and added a big blob of solder (this worked very well). The other end of this wire is soldered onto the switch.

Finally the tube is glued into place with some epoxy.


Step 5: End

Cut two slots in the end of the tube to retain the battery with a clip. Form the clip from e.g. a paper-clip, or other piece of stiff-ish wire. This has to be in just the right place, so take your time in getting it right. I can't think of the name for this type of clip (sorry)

Wrap the wire around the shaft, and finish with Gaffer-tape. It's not pretty.

So I took the tape off and improved the look of this, see next step.

Either 2 or 3 AA cells, will power this, slid down the tube (obviously). When using 2 I've had to improvise a dummy cell with card and foil.

L

Step 6: Finished Torch

Gaffer tape removed.
Most of the insulation was removed from the wire and the strands re-wrapped.
A bit more resin was added to the rear-end, with the clip-slots filled (temporarily) with card wrapped in PTFE tape. The open end was blocked with a piece of Blu-tac, wrapped in it's own waxy paper. The switch was masked with Blu-tac, and the LEDs masked with Blu-tac wrapped in plastic-bag
Sprayed with metallic paint, this looks much better

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    user

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    31 Comments

    Really cool project! I am working on something similar with a portable desk lamp, and some of the ways you did this really helped out!

    p.s. 4th step, 1st pic, you said "irrelavent" it's supposed to be "irrelevant"
    Dont take this as an insult (as some do), take it as a correction

    3 replies

    You missed these spelling errors: finaly, plasic, aroung, tewak and pictues.

    L

    whoops, i'm still acclimatizing to my new keyboard. Thanks though


    Well it may be over 3 years since I did this, but thanks.
    I'll go correct that.

    L

    I like this, Good work! It seems really do-able in an hour or less -- once you get home from Poundland or Poundstretcher and their aisles of cheap stuff that is just waiting to be bought and butchered for some better and ultimately higher calling. Which brand fibreglass resin was it? It's very smooth and clean looking, looks easy to work too. I usually use David's Isopon P38 for most things, having a resin one could pour would be a lot easier though!

    5 replies

    I got the resin from a cheap auto shop in Glossop... no particular reason, I just was in Glossop. (brand forget I) L

    I don't think the FB' would be interested, power company maybe. I did notice that someone hard used one of KipKay's images for a (yawn) tap-the-phone-line-for power-post recently, so thanks for inadvertently making me aware of the source for that.

    L

    Where was the post? In the forums here? Always only too glad to help -- whether I meant to or not! lol

    Doubtless you've read the 'ible, but my comment is only minutes old.

    user

    hint, buy some wands (like from cinema) or maybe from a one pound store there a great sorce of led's about 20 for £2 and brighter than the 15000MCD leds i bought online AMAZING!!!!!!

    great idea! but a small question why destroy the lighter? just undo the screw on the bottom push the button in and the whole light assembly drops out and you can still use the lighter after. i've been playing with these lighter LED's for a while and have even installed one in the front of my desktop pc replacing the hard drive LED it lights up the whole room. I did try one on the dog's collar, But he kept on chasing the light and running into things. keep up the good work

    1 reply

    Hehe, nice I read this & burst out laughing.

    good idea u take the gas out first ennit..

    6 for a pound?! Nice! I've been paying 99 cents each for these in the US! :( Damn that pesky capitalism. If left continually operating, how long would you expect a single LED to run off the three button cells?

    1 reply

    I've got no idea how long this would run, but based upon other similar devices which have been left on accidently - not very long (maybe a day?) L

    Good flashlight! P.S. These lighters are just wonderful source of Super bright leds. I use them to!! ;)

    user

    Cool re-use of tech, likening the whole resin look, shame about the duct tape really. Just a few suggestions;

    - For a better aesthetic you could run the wire under the resin (make it shorter so you don’t have to wrap it too), possibly to a metal o ring, with a metal cap slipping inside said o ring and the resin case making the battery contact. This would make it a lot more, polished so to speak, completed to a higher level of precision, in my opinion (rather than the gaffer tape and wire).

    -Use a number of switches for differing levels of brightness, this will allow for variable light levels at the push of a button.

    - Use some current limiting resistors, prevent the diodes cooking.

    Hope this is of use,
    Andy

    1 reply

    Updated, and more polished looking (last step) L