Bikers are vulnerable at night in traffic. Now, being vulnerable is fine, as long as it can be noticed by others. So what does a biker need to get noticed at night? That's right! Blinking starlight!

Have a look at the video:
If you can't see the video, take a look at it here.

But where I live, you can't leave your bike with cool led-lights on it. The lights will mysteriously disappear in a matter of minutes. So I wanted to make a bike light that:
  • ... you can wear and take with you
  • ... makes you get noticed by the traffic
  • ... is more or less water proof
  • ... makes you considered being cool by others (if you can't be cool wearing the gear you make, then what's the point of making it? ^_^)
This bikers light is made of an inner tube, stuffed with led's, a make-it-blink-circuit and a replaceable battery. Making LED's blink serves a bit more than just being blinky cool: Blinking also saves a _lot_ of energy, because the led's are on only 20% of the time. That makes the battery last 5 times longer compared to led's that are continuously switched on. By using a flip-flop-circuit to make the leds blink, only one 3 Volt battery-cell is needed to make the leds blink for over 15 hours.

Stuffing an inner tube with electronics is a bit like putting a ship into a bottle: It can't be done, unless you know the secret. The secret for stuffing an inner tube is to flip it inside out. Then mount the electronics, and then flip the tube back, with electronics and all.

In the six following steps are over 50 pictures of the making of the Flip-flop-inner-tube-bike-light. Comments are added to most of the pictures. Have fun making your own inner tube bike light!

Step 1: Tools and materials

Although three pictures are needed to display the tools and materials you need, there's nothing complicated about it. Here you go:


For the inner tube led-array:
  • Inner tube (of a bike. It's going to be a Bike Light, you know)
  • Paper sheet (to take the measure of the bike light's circumference)
  • 8 - 10 leds, 5 mm model (I used to cheapest possible leds (€0,05 a piece), just because I had them around. You might want to choose more efficient leds. If you do, take notice of the desired current through the leds: The circuit can deliver a max of 200 mA for ALL the leds!)
  • 2 x 70 cm (45") of stranded wire, in different colors
  • Silicone gel (to seal the leds in the inner tube)
  • A silver marker
  • Duct tape (of course!)

For the flip-flop circuit:
  • 2 electrolytic capacitators (elco's): 1 x 100 uF, 1 x 22 uF
  • 4 Resistors: 2 x 1 kOhm, 2 x 10 kOhm
  • 3 Transistors: 2 x BC547, 1 x BC557
  • Jumper wire (or just some stranded wire you ripped out of a junkyard PC)
  • Circuit board

For the powersupply:
  • 1 CR2450 cell battery
  • 1 battery clip for the CR2450 model (PCB version! I used a SMD-version, which I had to hack into a PCB version :-s)
  • Switch that can be mounted onto a circuit board.
  • 6 small Tie-raps (to fix the leads between the circuit boards and the led-array)

For the electronics:
  • Soldering iron and solder
  • 3.5 mm drill (0.14")
  • Cutting Pliers
  • Needle nose pliers
  • Stripping pliers
  • Multimeter (just for checking and/or debugging)
  • Third hand
  • Small saw or dremel to cut the circuit board
  • Water proof sanding paper (roughness 300 or higher)

For preparing the inner tube:
  • Punch, 3 to 4 mm (0.12 to 0.16") diameter
  • Scissors
  • A _metal_ ruler (to punch holes into _one_ side of the tube, not both)
  • Pvc tube (1" diam) that is longer than the piece of inner tube you use
  • Some cardboard (to mount the led-array when soldering)
  • To flip the inner tube inside out: a long, thin, stiff rod with a loop or hole on one end :-D Find a name for that tool: Flipping aid? Flip-rod? I used a cross-brace that comes with ikea's GORM racks. Worked like a charm.)
<p>Can these circuit work with 2 Ni-Mh batteries (2.2-2.4v) ? </p>
<p>Hmmmmmm... maybe. To light regular red or green LED's a voltage of about 2-2.5 Volts is required. The voltage over the BC557 transistor is about 0.6 Volt. So with 2.2 Volt battery voltage, you have about 1.6 Volt at hand for the LED's. I can think of two ways that might work:</p><ul><li> Use low-current led's, like these: <a href="http://www.kingbrightusa.com/images/catalog/SPEC/WP7113LSRD.pdf" rel="nofollow">http://www.kingbrightusa.com/images/catalog/SPEC/W...</a><li>A bit more tricky: Replace the BC557 with a FET with similar specs. FET-type transistors have a lower internal resistance than the BC557 I used. The BS170 might work: <a href="http://www.fairchildsemi.com/ds/BS/BS170.pdf" rel="nofollow">http://www.fairchildsemi.com/ds/BS/BS170.pdf</a></ul><p>It's worth a try, I think. The easiest way is to use the low-current led's. If that doesn't work well enough, try replacing the BC557...</p><p>Good luck,</p><p>Y.</p>
I recognize your solder holder, I got one just like it from think g33k.
Heb je alle onderdelen bij conrad gekocht?
Uuuhhmmm, alles is in elk geval wel te koop bij Conrad. Een gedeelte kwam uit m'n schuurtje, en dat betekent dat de herkomst echt onbekend is.
Bij conrad bieden ze verschillende versies aan: BC547A, BC547B, BC547C.<br>Wat zijn de verschillen en welke moet ik hebben.<br><br>alvast bedankt.
Maakt geen fluit uit voor deze toepassing. Ik heb de BC547B TO92. Artikelnummer 155012 (handig toch, dat ik bonnetjes bewaar :-D)
Luv that Patch...I Want one...PLS...
<a href="https://www.instructables.com/id/Blinky-the-LED-pet/">Blinky the LED Pet</a> earned the Patch for me :-)
Hi there Would u pls vote for my entry ...?<br>https://www.instructables.com/id/Homemade-Belt-No-sew/<br>thnks
done. :-) Nice I'ble!
Thnk u so much...i&acute;ll do the same when u need it...
Instead of using a hole puncher which you say is tricky, I would place a wooden batton inside of the tube then using a pair of pliers and a nail of the right diameter. Holding the nail with the pliers and heating the tip of the nail and burning a hole through the rubber with the wooden batton stopping it going through the other side.
Yep, that could work! Smart! I punched some extra holes in a watch-strap that way, a while ago. The punch works fine, by the way, but you need to take some precautions not to punch both sides of the tube...
simple but fantastic idea!
Thanks! :-)
great idea, but unfortunately, as the law goes in the uk, you can have a flashing light attached to the bike, but not attached to the person... I know. sounds bonkers (its not my rule)
...but is it _forbidden_ to wear a flashing light? In The Netherlands, lights must be attached to the bike, a white light on the front and a red light on the backside, both not flashing. But, not surprising in NL, lights attached to the person are &quot;allowed&quot;, although officially they're not.<br><br>Anyway, kids can never wear too many light on a bike at nighttime, I guess :-)<br><br>To make my bike-light fully-not-officially-legal in NL, you should wear two of them, one red and one white. Both non-flashing. The flip flop circuit should be tweaked to flash at a frequency of about 100 Hz: The leds appear to light up continuously, because our eyes can't keep up with the frequency. So you will still save energy from the battery.
in the uk is similar, where you need a white one on the front and a red at the rear.. The bike itself is allowed flashing lights, but the person can only wear solid, constant lights..<br><br>I guess its somethign to do with the rider being higher and could dazzle road users as they are higher up..
It's not illegal in the UK to wear a flashing light on clothing when cycling and never has been. However, up until Nov 2005, it was illegal to have flashing lights on cycles, but now the law is ok with flashing lights. They are supposed to meet British Standards, have defined flash rates and colours, etc. However, it seems unlikely you'll be prosecuted in the UK if you actually have lights on your bike whether they meet BS or not so long as they are effective and working.
Great detailed Instructable!<br> <br> &quot;&bull;To flip the inner tube inside out: a long, thin, stiff rod with a loop or hole on one end :-D Find a name for that tool: Flipping aid? Flip-rod? I used a cross-brace that comes with ikea's GORM racks. Worked like a charm.) &quot;<br> In the US the colloquial term is a &quot;fish&quot; as in a wire fish used to pull electrical wires through a wall or thin electrical metal tubing (EMT). Great improvisation.&nbsp;<br> <br> Most US jurisdictions have rules on flashing bike lights including read on the rear. Often broken, where I live is very liberal contrary to many other of the laws. Go figure.<br> <br> Every bicycle ridden between sunset and sunrise must have at least one white headlamp with the light being visible at least 500 feet to the front. The bicycle must have a red reflector on the rear visible at least 600 feet to the rear. On roads posted with speed limit of 35 mph or greater, the bicyclist must additionally be equipped with at least one red taillight visible from 500 feet to the rear. <u><strong>Taillights may be steady or blinking, are allowed under all conditions</strong></u>, <u><strong>and may be attached to the cycle or rider. </strong></u><br> <br> Code of Virginia &sect; 46.2-1015.
I like Fish as a word for the Flip-rod! Finding a way to pull an inner tube inside out, and then discovering that the tube with mounted leds can be flipped back, was the most fun for me while making the Ible :-)<br><br>Thanks for the rules on bike-lights, both in US and UK (Cinderellaman)! I'll look up the precise rules in NL, and try to make a &quot;traffic-rule-proof&quot; version of the bike light. And also use more powerful leds then.
This would look really cool with a few inches of mountain bike tire. They do really well with leather punches (LEDs look lik #2 or 3), and are a lot more durable and tear-resistant.
;-)<br><br>How's Nijntje called in the US / UK? She's a Stargazer on a cloud!
Nijntje is called &quot;Miffy&quot; or something here in the US... I just know her as Nijntje Pluis.
Nijntje Pluis is her Dutch name, and the hero of dutch kids for several generations. My mother, me and my daughter grew up with the stories of Nijntje Pluis.
Like your stargazers :)

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Bio: Also have a look at member Monster-Marit. She Rocks (I'm a bit prejudiced, though :-))
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