Step 4: Create the Velcro strap

Make sure you have enough Velcro to fit around your forearm with a several inches to spare. For me 15 inches was enough, but I don't spend lots of time at the gym.

Hook or loop doesn't matter, as long as you have a long piece of one and a short piece (an inch or so) of the other.

Hot glue one end of the long strip to the bottom of the battery enclosure. Make sure it's hook or loop side facing the battery holder. Put it on the "up the arm" end, furthest away from where the armature wire sticks out, and pointing away from our little gap we left for our strap. Again, the picture is worth a thousand words.

When the glue cools, put the strap through the strap hole we left in step one. Then hot glue the short bit near the end of the strap. Leave about 1/2 inch to make it easier to pull off. Glue it on the hook or loop side, not the smooth side. (You could also stitch it, but the glue gun is already hot...)

You should now have an adjustable strap that will secure it to your arm.

Give it a try, put your arm through the strap and see how it fits.
Reminds me of the goonies.
Wow product of the day! Been a while since I've seen this project! There were some awesome entries for the particular "LED out" contest, good prizes too (especially the runner up prizes ;)) Was looking at the Monkeylectric website only yesterday, the video pro 7 is amazing.
My 7 yr old son and I put together a pair of these. He loves them. Now he wants to make them for Christmas presents.<br><br>I am wondering if you could do this project with only 1 LED instead of 3? If so, what size LED and resister would you suggest? Would the power input be the same too?<br><br>Please keep in mind I am not an electronics geek type. But I am willing to learn.<br><br>Thanks!
mmmmmm so you have to constantly keep you arms in that position or move around the lights every couple of seconds<br><br>wouldn't it be more effective on your shirt or shoulder or any where like a head unit so you can freely move your arms around<br><br>even a torch in your mouth allows for better light
Quite the opposite. When you have a head or body mounted lights you have to hold your head or body in position to keep the light pointed at your work. When they're mounted on your hands the light is automatically pointed at where you are working.
Hi<br><br>Thats my point you have to reajust for different angles but with something like head mounted you just look at it any way and don't need to adjust if not in the same possition<br><br>And somthing like shirt mounted will give you a better spread of light to cover the work area if it needs to be brighter just hold it closer and if it's to bright just a little further, and for both it just needs one set of lights not 2<br><br>Your idea is another way of looking at it anyway<br>and makes people think of other ways<br>keep up the experimenting
is it ok if your battery compartment holds 4 AAA batteries? or can it only be 3?
It's fine, though you'll need different resistors since you'll be putting more voltage through the circuit.<br/><br/>There is a simple calculator at <a rel="nofollow" href="http://led.linear1.org/led.wiz">this link</a> to figure out what resistors you need. If you're going to use 3 of the same type LEDs I used you'll need one 100 ohm resistor for each LED.<br/>
cool thanks
put your leds in series instead of in parallel. <br>2 leds in series creating a row, and 2 rows parallel with each other
when only 4 cell holders are available, make a &quot;dummy&quot; battery. i have heard of using a dowel which is drilled down the middle. place copper disks on each end and solder a wire running through it. bits of old circuit board work well, as does cu flashing. that way u still need use only 3 batts and don't need larger resistors to throw away more power. 4.5 vdc(source) minus 3.4vdc(the led) divided by .02(20ma)=55 calculated ohms. for long term use go to the next highest fixed resistor. <br> 'able a good idea. keep up the excellent work. unclecytheledguy.
Great idea, similar to the HexLight shown on the tv show Pitchmen:<br><br>http://dsc.discovery.com/tv/pitchmen/inventions/inventions.html
Shame that I published my Instructable more than a year before the HexLights episode.<br><br>Wonder if one of us was copying the other?
I do remember them mentioning in that episode that there was at least one patent on a similar type of device and that they wouldn't be able to make the HexLights. But then they made a slight change to the design and the patent infringement no longer applied.
I was just about to say that, but then i saw your comment.
Where exactly can you get this armature wire? I'm finding it hard to buy in small amounts. Can I substitute some other type of wire instead? Thanks, Miksa
Art supply stores. But you can also use heavy gauge copper wire -- like 10 gauge or lower -- any home center will have some. leave it insulated or strip it. Copper is pretty!
I don't know of anywhere you can buy it by the foot, unfortunately. Art stores have it in their sculpture sections, it can sometimes be called &quot;Craft wire&quot;. <a rel="nofollow" href="http://www.dickblick.com/products/armature-wire/">One Supplier</a>. <a rel="nofollow" href="http://www.pearlpaint.com/buy-1-8in.-x-20Ft.-Armature-Wire_2999_2964_176132.html">Another</a>. <a rel="nofollow" href="http://www.google.com/products?q=armature%20wire">A great many suppliers</a>.<br/><br/>You can also find something similar at hardware stores if you shop for aluminum wire, which can also come in <a rel="nofollow" href="http://www.amazon.com/s/ref=bl_sr_kitchen?ie=UTF8&search-alias=garden&field-brandtextbin=Aluminum%20Wire">a bunch of colors</a>.<br/><br/>It has all sorts of uses. <br/><br/>You could cut up a wire hangar to use but it wouldn't be as good as aluminum. It would make it harder to build because the steel wire is harder to shape, and the the light position wouldn't be as easy to adjust because the steel is springy and won't say where you put it. But it would work.<br/><br/>
excuse me can i ask what are the possible materials to replace the velcro
Here are some other options, but Velcro will work the best:<br/><br/><ul class="curly"><li>Nylon strapping with a buckle (<a rel="nofollow" href="http://www.strapworks.com/LWP_s/108.htm">like these</a>) You might be able to scrounge one from an old backpack or bag.</li><li>Make a metal bracelet from a wire hangar. Cut the hook out of a the hangar and bed the wings into a loop a little smaller than your arm. Glue in place. Make sure you cap any raw pointy bits of wire.</li><li>Shoe laces or ribbon. Take two shoe laces or lengths of ribbon and glue one to the front and one to the back of the battery holder. Glue the laces at the mid-point. Put it on your arm and tie 'em up. This will probably be a pain since you have to do it one handed.</li><li>Cuff from a sock. Cut the top 4 inches off an old sock and hot glue it on. It won't be adjustable, so make sure it fits right on your arm before gluing.</li><br/></ul>Those are my ideas off the top of my head. Anyone else have any suggestions?<br/>
Ok good, we have a Ben Franklin in town, so I don't have to wait on shipping from over the internet. How about the battery holder? Can I do a 4 AAA holder, or will that be too much voltage?
You can use 4 batteries, but it will likely change what resistors you use.<br/><br/>To figure it out either go <a rel="nofollow" href="http://led.linear1.org/led.wiz">here</a> and put 6 volts for the source voltage and fill in the rest with the specifications from your LEDs, or you can follow <a rel="nofollow" href="http://www.instructables.com/id/Choosing-The-Resistor-To-Use-With-LEDs/">this instructable</a> to calculate the resistors you need.<br/>
I love your project mate. And i'm working on a way to miniaturize the design, in order to be able to fit 2 of these to my Wayfarer glasses for night study, Project making, late trips to the fridge etc, perhaps using a smaller LED, and smaller batteries, what do you think?
You certainly can shrink it. You could power them with a couple of watch batteries. (Or if you don't need a ton of light, basically just make a <a href="http://www.instructables.com/id/LED-Throwies/" rel="nofollow">throwie</a>.) Of course you'll need to change the batteries more often, but they should last a few hours at least.<br> <br> For the late night lights, consider making them with red LEDs, they won't kill eyes that are adjusted to the dark
I&nbsp;think your idea is absolutely astonishing, but instead of using &quot;plenty&quot; of electrical tape, why not use heatshrinking tube; just a 3am thought&nbsp;:)
Of course! &nbsp;I wanted to keep these instructions as simple as possible using the most common&nbsp;supplies, which means there are limitless possibilities for improvement.
instead of 47 ohms, i used ohms law to figure out that r should be 120 for&nbsp; <br /> 30 mA and 3.6v. nice idea! im going to make this with only 1 battery pack and a wire running down your arm and your other arm so you can have 2 sets for half the batteries! i had a thought that was wierd! run some wire from your power source through your underwear and next to your socks. that would feel wierd!<br />
Ask, and ye shall receive.<br /> I did things a bit differently.&nbsp; I used just one resistor for all thee LEDs instead of one per LED.&nbsp; The LEDs I used, Digikey C503C-WAN-CBADA151-ND ($0.54), are a bit more focused than yours.&nbsp; If I was to do it again, I might us more diffused ones.&nbsp; I also put a nifty little pot, Digikey 3352W-101LF-ND ($1.24), in parallel with the resistor.&nbsp; It was a 100 ohm resistor and a 100 ohm pot so the resistance can be varied between 0 and 50 ohms.&nbsp; I thought this would let me conserve batteries if I so choose and crank up the current when the batteries start to die.&nbsp; I also used a push button, Digikey 518PB-ND ($1.19), to turn it on and off.&nbsp; For the main supporting wire I used the wire from marking flags.&nbsp; The flags used to mark buried cables, Harbor Freight item number 95264 ($1.49 for 25).&nbsp; Instead of running two wires up to the LEDs, I used the supporting wire as one connection.&nbsp; So I soldered the three LED cathodes right to the supporting wire.&nbsp; The wire, being galvanized, wasn't exactly conducive to soldering but with enough heat and solder it seems to be holding quite well.&nbsp; I drilled a hole through the battery holder and ran the support wire through it where the support wire first meets the battery holder to add a bit of strain relief.&nbsp; This way adjusting the support wire won't put quite so much strain on hot glue alone.&nbsp; The battery holder part number was Digikey BC3AAW-ND ($1.22).&nbsp; For the velcro straps I used Harbor Freight item number 66125 ($1.99).&nbsp; These already had a plastic buckle on one end so I didn't need to used your spiffy trick of using the support wire to make one.&nbsp; Because I wanted to keep both ends of the straps but they were way too long I took a section out of the middle.&nbsp; I just cut some out of the middle and sewed it back together.&nbsp; I used a razor blade to shave off some fuzz to make the seam smooth.&nbsp; I also shaved off all the fuzz where I hot glued the battery holder to the strap.<br /> <br /> I love my hand lights.<br /> <br /> If you'd like to add any of this comment to the main part of your instructable please feel free and thanks for the great idea.<br /> <br /> <br />
They look fantastic!&nbsp; Thanks for sharing your excellent build notes and materials list.&nbsp; Your <em>Master of Hand Lights</em> patch is on the way!<br />
great concept. :)
Wow, I can really see this being useful for gaming at night. Typing on my Laptop has always been terrible. I've been looking for a way to light my keyboard effectively. Grats on the contest!!
well at night you might want to use red LEDs so they don't mess up your vision. if you want to know what I mean go some place pitch black, wait till you can see without a light then turn on a flash light or something then turn it off. you wont be able to see for a while but with red light it wont mess up this vision.
Thanks for all the support everyone, you guys really made my week! I have just one request: If you make one, please some photos! The comments have some really great ideas and I'd really like to see what you guys can do. Post 'em in comments or email/private message me directly, whatever. A little shameless self promotion never hurt anyone!
you should actually consider marketting this product...unless there already is such a thing around...I personally have never seen anything like it
The item is great, but more than that is the concept behind. A very, very useful tool with tons of potential. Please, listen to the other members and try to market it, or at least patent it before a big-box-blood-sucker company does, stealing YOUR great idea. Instructables like this make me addict to it. I've faved it. Cheers!
Thanks for the encouragement everyone! Now to find that five start Instructable on "Marketing" and "Bringing a Product to Market". Both things that I don't particularly have the temperament for.
Right? I want to see that instructable too. I can't tell you how many times I've wanted to try something out like that, but not had the first clue how to do so.
I'd buy two =)<br/>
i second that. i would definately buy one of those.
This would be a good alternative to a headlamp for camping because then you won't have insects flying at your head.
it is agood idea
i really like this!! after my exams i'm going to see if i can make one of these...
lol me too :)
I love this 'ible, such a great and simple idea. Somehow a bit Startrek and rather cool
Great idea! If you're going to try to make a market version, you may want to think about adding one of the reflectors you find inside small flashlights. With that, you could create a way for focusing the light. I'm going to try to build one with this tomorrow, these things would be great for soldering circuit boards in my dimly lit lab space. Thank you so much!
Another really good idea! If you get a chance post a photo of yours! I'm really curious to see what you guys are capable of.
You could save yourself one wire and use the armature as one of the connectors. Plus, it will look cool as there is only one 'wire' running to the LED's.
You might want to attach the battery pack to the back of your arm using thick elastic that also attaches to the light or maybe a pull-to-tighten strap. This way you are able to better bend your arm when using these.
<a rel="nofollow" href="http://www.uspto.gov/web/patents/howtopat.htm">http://www.uspto.gov/web/patents/howtopat.htm</a><br/><br/>that is how to get a pattent, i would do it ASAP before someone steals it, this could make huge money! i think at least<br/>

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Bio: Creative swashbuckler. Writer for MAKE Magazine, presenter of inventions on TV, radio, magazines and newspapers. Professional problem solver. Annoyingly curious. Hacker of all things from ... More »
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