Lasercut BraceLED Bracelet

In 2011 I made a bracelet with ducttape and LED's (I named it BraceLED. Duh.) The bracelet's clasp is a small magnet that also acts as a switch, so the leds only light up when you're wearing the bracelet.

This spring (2013) a few things happened:

• I did a workshop with high school kids, making BraceLEDs. And they really, really liked doing that.
• That day I also met a man called Leen. He was there doing workshops with a 3D printer and... a lasercutter.

Two weeks ago, I did a nighttime workshop (from 8 pm to 1 am...) with adults this time, again making BraceLEDs. And them too really, really liked doing that.

Funny thing: Although "bracelet" sounds like "for women", braceLEDs are equally popular with men and women, boys and girls. Being able to design your own helps with that, I guess.

So: Many people enjoy making BraceLEDs and Leen has a lasercutter: Last week Leen and me joined forces and made a new version of the BraceLED, with the aid of Leen's lasercutter. We'll be doing try-out workshop with kids on June 22nd. I hope to have some pics of kids' results by then. In the meanwhile, here's a video to show how the clasp / switch works:


If you have access to a lasercutter *), making the BraceLED will take 30 mins to 1 hour. Costs are around €2,00 per BraceLED, but there is a catch: Although you need only 30 cm of coppertape, you must buy a 15ft roll if you don't have it lying around. And that will set you back around €8 (US$10).

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This I'ble is an entry in the Epilog Challenge. If you like it, please give it your vote (you can vote for as many I'bles as you like). Thanks!
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*) If you think you _don't_ have acces to a lasercutter: Lasercutters tend to nest in FabLabs, Maker Spaces, Hacker spaces or Tech Shops. Look for them in in your area. 

Tools:

• Black markers / sharpies with a big tip
• Soldering station
• Scissors and / or knife
• Cutting pliers
• A laminator (only needed if you make the BraceLED of laminated paper)
• Lasercutter
• Software: a vector based graphics program like Adobe Illustrator, Corel Draw, Ink Scape
• A scanner or photo camera to get your design into a computer

Materials:

• Ducttape in various colors, or:
• Plastic coated paper
• Copper tape
• 6 to 12 LEDs. Any color you like. I use mostly red, yellow and green leds for workshops because they're cheap. Blue, white and RGB-leds are more expensive. You can even use blinking leds if you like.
• Coin cell battery, 3 Volt, model CR2016 (Buy smart! Prices differ from €0,44 to €2,95 a piece!)
• Supermagnet (disc shape, 15 mm diam, 2 mm thick)
• Double sided sticky tape

Where to shop:

• Coppertape: Conrad, (Europe only. If you know a link to a US shop, please let me know). Avoid 3M's shielding tape. It's great stuff, but really expensive.
• Magnet: Supermagnete.com
• LEDs: Anywhere (Radio Shack, Conrad)
• Ducttape: Duck Tape (the brand) comes in _any_ color you like :-) I bought it at my local hardware store, €5 for 10 meters. Amazon is waaaaaayyyyyyy cheaper!

The braceLED in the picture is just the BraceLED I made. It's completely up to design your own braceLED. Here's what you do:

Choose the material you want the BraceLED made out of. Laminated paper, ducttape, maybe even leather. Anything flexible, cuttable by a lasercutter and more or less resistant to soldering heat works. More in step 6 about materials.

• You can use the template (pdf) as a guide for your braceLEDs design. The black shape in the template provides space you need to mount the LEDs, battery and magnet. The remaining space is yours to be filled in.
• When you're happy with your design, draw it with a black marker. The outline of the black shape will be cut by the lasercutter later on.
• Scan your design (or take a picture).
• Place the image of your design into a vector based graphics program. I use Adobe Illustrator (CS 4 version, dutch version) here, but the basics are the same in other apps. (note: Pro graphics users recommend to convert the image to grayscale, but for this purpose it's really not necessary)
• Select the image and choose Live Trace -> Trace options (screenshot)
• In the pop-up window (screenshot), check Preview and tinker with the options until you're happy with the trace.

Click Okay and you're done. Delete the original image and make on outline drawing of the traced design (no fill color, line color red, thickness 0.1 pt or so).

Send the traced image to the lasercutter. I can't help you here, because the how-to for that depends on the type of lasercutter you're using. If you're in a FabLab / MakerSpace / Tech Shop / etc, ask the staff. They'll know what to do.

NB: If you're comfy with vector based drawing, you can design the entire BraceLED in Illustrator of course. The result will be quite different than hand drawn designs.

The braceLED in the main image is made of plastic laminated paper. I also made a version out of ducttape. I stuck two layers of ducttape onto eachother, and just gave it a try in the lasercutter. With a little adjustment of the lasercutters' setting, it worked fine. Have a look at pictures 3 and 4.

So, laminated paper and ducttape can be used. I image that different kinds of fabric, leather, rubber work as well. I didn't try that, so please have a go with that and let me know how it worked out for you.

Now you have your design made tangible by the lasercutter, it's hardware time. The steps require a specific order:

1. Lay down the BraceLED with the backside facing up (picture 1).
2. Cut out a piece of double sided sticky tape as big as the battery.
3. Stick the tape into the "battery-spot" on the braceLED.
4. Cut a piece of copper tape and stick it across the double sided sticky tape to an edge of the braceLED (picture 2)
5. Cut a strip of copper tape as long as the braceled and not thinner than 4 mm (1/6") (or you'll get in trouble soldering the LEDs)
6. Stick the copper tape strip to the BraceLED and let it overlap with the small copper strip you added before (picture 3)
7. Add a second strip of copper tape on the other edge of the BraceLED (picture 3).
8. Now place the battery _with the smooth plus-side faced downwards_ firmly over the copper tape on the sticky tape (pictures 4 and 5).

Done? Cool. One of the copper traces is now connected to the plus-side of the battery. To let the LEDs light up when wearing the BraceLED, the other copper strip must be connected to the battery's minus-side (facing up) when the BraceLED is closed:

Have a look at pictures 6, 7 and 8:

• Cut a strip of copper tape 4 mm wide and about 5 cm long.
• Stick one end of the strip across the "minus trace" on the BraceLED (picture 6).
• Fold the copper tape strip over to the other side (that is the outside when you wear the braceLED)  (picture 7).
• Check: When you close the BraceLED now, the copper tape on the outside should touch the battery's minus-side.

 

Finally, time to add LEDs to your BraceLED!

The LED polarity issue:
Keep in mind that LEDs have a plus-lead and a minus-lead (named anode resp. cathode).
Accordingly, there is a plus-trace and a minus trace on the braceLED: The trace that goes under the battery is the plus-trace.
So you'll have to solder the LEDs plus-lead to the plus-trace, and the minus-lead to the minus trace.

A led's minus-lead is easy to identify: It's the shorter one of the two leads, and there's a small bevel on the dome's rim above the minus lead (picture 1).

Soldering:

• Lay down the BraceLED on two pieces of scrapwood (or books) with a slit in between, right under the holes through which the LEDs will appear.
• Spread the LED's leads 180º
• Put the LEDs through the holes of the braceLED, the leads crossing the copper traces (remember the polarity issue? :-))
• Solder the LEDs onto the copper leads *).
• Put a dab of solder where the copper leads overlap.

Test it: When you close the braceLED, push the flipped over minus lead against the battery. The LEDs should light up (picture 5).

*) If you use ducttape: Try to solder quickly, because ducttape is not very resistant to heat. If you're unsure about your soldering skills, do a test on some scrap ducttape and copper tape first. Remember, people who never soldered before made perfect braceLEDs with ducttape. You can do it. Really. Trust me :-)

Almost done, the final step is the easiest one!

With a small piece of double sided sticky tape, stick the magnet on the end of the braceLED, opposite of the flipped over minus trace.

The magnet works as a clasp, because it sticks to the battery pretty firmly (that's why  a super magnet is needed :-)).

Debugging the clasp: Sometimes the LEDs start flickering: Add an extra piece of copper tape and a dab of solder on the minus-contact (where the minus-lead touches the battery.

I'm considering using press studs as a clasp instead of the magnet, but I didn't try it yet. Anyone?

You're done now! Congrats with your design-it-yourself (hey, that's DIY!) braceLED! Pics of braceLEDs you made are GREATLY appreciated in the comments :-)

This instructable is an entry in the Epilog Challenge. This is why:

My friend Leen and me are teaming up to do workshops with K12 students (Europe: 6 to 16 yr old pupils). The workshops are a mix of design, art and technology, enabling kids to imagine, design and make their own projects. Here's a video made during a workshop making BraceLEDs:


Lasercutters are a perfect tool for us to use during the workshops: They're fast and versatile, and kids love to work with them. Leen owns a self built lasercutter, but I do no not, alas. Besides that, the lasercutter is an oldie: Etching is not possible and there is a separate driver-app needed to upload jobs to it: Visicut. Fine for us, but tricky for kids to do it themselves. In short: We could surely use a brand new Zing 16 lasercutter :-)

If you like this project, please support us with your vote in the Epilog Challenge. It's greatly appreciated!