Instructables

Cheap homemade LED torch (full build)

Picture of Cheap homemade LED torch (full build)
A cheap source of LEDs
A full torch / flashlight
 
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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
beehard443 years ago
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
lemonie (author)  beehard443 years ago
You missed these spelling errors: finaly, plasic, aroung, tewak and pictues.

L
whoops, i'm still acclimatizing to my new keyboard. Thanks though
lemonie (author)  beehard443 years ago

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

L
xerxesx205 years ago
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!
lemonie (author)  xerxesx205 years ago
I got the resin from a cheap auto shop in Glossop... no particular reason, I just was in Glossop. (brand forget I) L
Ah, righty right.

Thanks for getting back to me.

Whaddya reckon to this...

Read the comment I left on it, following on from another historic post (seems to be a hobby of mine!) the comment is about halfway down when looking at it in allsteps mode.

http://www.instructables.com/id/FREE-Hidden-Electricity!/

8-)
lemonie (author)  xerxesx205 years ago
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.
dg335 years ago
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!!!!!!
warpspawn6 years ago
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
Hehe, nice I read this & burst out laughing.
trigger-don5 years ago
good idea u take the gas out first ennit..
Kelani7 years ago
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?
lemonie (author)  Kelani7 years ago
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
Zujus7 years ago
Good flashlight! P.S. These lighters are just wonderful source of Super bright leds. I use them to!! ;)
andy7 years ago
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
lemonie (author)  andy7 years ago
Updated, and more polished looking (last step) L
andy lemonie7 years ago
oo, cool, now that looks better, no doubt it will last longer too, well done! Andy
lemonie (author)  andy7 years ago
The diodes run from ~4.5 V as the original lighters, and they're nice and bright. It would be a sod if they failed, but I'm hopeful that they won't for a while... The aesthetics are poor, but as a previous comment, this is because I couldn't finish nicely due to rain. Hope to update.
I live in the states, is a pound about the same as a dollar, if so did you get them at the equivalent of a dollar store (pound store)? I could really use the butane and the pezo's
lemonie (author)  TheCheese99217 years ago
It would be equivalent fo a dollar-store. (at today's rates a pound is ~2 dollars, which is a relatively strong pound)
dchall8 lemonie7 years ago
Or you could go to Radio Shack and buy their entire inventory of RTU LEDs for a dollar or two. I like this one. At first I glossed over the resin on the paper tube, but that's pretty cool. If you rolled up soda straw spacers inside the paper with the batteries, you could run the wire inside with the batteries and keep the outside pristine. I was trying to come up with a PVC fitting you could use as the mold and then glue the bulb assembly directly onto 1/2-inch PVC pipe. I guess it would have to be the sleeve to join two pieces of pipe. I think the resin you used is polyester boat resin. Is it mostly resin with a few drops of catalyst or is it more like a 50/50 mix of resin and hardener? Polyester boat resin uses only a few drops of catalyst. Epoxy uses a 50/50 mix or slightly different. As long as you're rolling up paper and coating it with resin, you could use fiberglass with a second coat of resin and really have a sturdy flashlight.
lemonie (author)  dchall87 years ago
It stinks of styrene, so I'm thinking it's mostly styrene, maybe with some DVB, who knows...? The hardener is dibenzoylperoxide, so it's largely a radical polymerisation of styrene, and yes it is cheap resin. L
jolshefsky7 years ago
An alternative to the wire along the outside of the tube would be to wrap in a layer of aluminum foil and use that as a conductor, connecting a wire to the top and bottom. Well, or maybe just fold it into the inside on the bottom and the clip will make electrical contact to the foil and to the battery.
lemonie (author)  jolshefsky7 years ago
I did think about this, and only being held on with tape I can still do it. However, it was raining a lot last weekend, so couldn't use the resin without poisoning the atmosphere. I'm much inclined to do this at a later date. L
Now THAT is an LED Flashlight! Awesome work, L! -Muffin
One slight improvement? Arrange the LEDs so it makes a smiley face! I love friendly flashlights ;)
lemonie (author)  T3h_Muffinator7 years ago
Yes I found that I had a 'dud' amongst the six. I couldn't see why this failed, but encased in resin, there's nowt I can do about it now.... L