Instructables

Bike Turn Lights

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Picture of Bike Turn Lights
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This is my first instructable, and I will show you how to make yourself safer by having turning lights pointing left or right so that the drivers know which way you want to turn when riding your bike, especially at night. I made this instructable when I first discovered this website and saw the contest. It also looks pretty cool in the dark. So if you're interested, keep on reading... 

 
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Step 1: The materials and tools

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Materials:
- 18 red LEDs 2.6 volts
- 2 green LEDs 2.1 volts
- 6 resisters 1/4 watts, 220 Ohms
- Wire
- A plastic box approximately 4.5x9x1 inches
- Cardboard
- Aluminum foil
- One 9 volt battery
- 1 battery holder
- 2 flip switches
- 1 switch
- Duct tape
- Electric tape
- Multi-purpose ties

Tools:
- Solder
- Soldering iron
- Pliers
- Wire stripper
- Scissors
- Exacto knife
- Ruler
- Pen
- Super glue

Step 2: Building the base

Picture of Building the base
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O.K., let's get started.Take a piece of cardboard and draw a triangle so that it fits in the box and so that both triangles still have about 3 inches in between them. Measure about a 1/2 inch away from the triangle. Then cut the cardboard with an exacto knife and trace it to make a second piece. Cut very shallow on the line where the triangle is to bend the cardboard pieces so that they can "stand up". (Look on the picture because it might be confusing.) Then put the triangles in the box and adjust it if it doesn't fit.  

Now, once you're done with that, glue aluminum foil to the triangles (not the parts that bend!) and let it sit overnight. I added aluminum foil so that it acts as a reflector for the LEDs. Make sure that you leave plenty of room around the triangles so that when you're done, bend the aluminum foil to make a border around the triangle.

Poke 9 holes in each triangle so that they aren't too close to the ends.
I did it a bit differently, but this way's probably easier.

geoper23 years ago
Nice one ! i was thinking of putting a light for stop on mine :P every time i press the brakes haha but i thought it would be kinda funny
abecar123 years ago
i think this is kool but a small improvements you could make is use a brighter led or a different resistor like a 1/4 watt 680 ohm. also you could add flasher and a tail light in the center to use as a indicator. don't make its as bright but bright enough that they can see. you could also move the switches under the handle bars by the wheel almost the sideways "v". if you do i would use plastic and zip ties. also to make it look better drill a hole in the frame run the wires through the bike and cover the two holes with a small rubber grommet or something to seal the hole from rust and stuff.
zascecs (author)  abecar123 years ago
Thats cool, thanks.
luvit4 years ago
 this is epic. you could make it the shape of a pointing finger in either direction.
zascecs (author)  luvit4 years ago
Thanks, that would be pretty cool. Maybe I should try that... 
luvit zascecs4 years ago
 don't have a finger point up. that's an important detail.
ClaireW015 years ago
Is it possible to make the left turn signal red and the right turn signal green? Just for emphasis, because a bike is so small compared to a car or delivery truck.
zascecs (author)  ClaireW015 years ago
Yes, you could. Just use green LEDs.
cool you could of used flashing leds for this and wired them up to a center pole Flip switch and control them with one switch or two small momentary push switches
carpespasm5 years ago
not bad, you could add an automotive flasher to this and have the turn signals blink as well. You'd probably need to re-wire them to run on 12v though. Running it on 9v would probably work, but the blink time would be longer and it'd probably eat 9v batteries pretty quickly.
i don't thing so. thermal flashers require quite a bit of load, so if u wire it up to the LEDs, it wont flash at all
I think it would probably be better to use an Arduino and make a quick animated pattern vs. flashing...
An arduino (while seemingly the lifeblood of almost all i-bles involving LEDS) is a bit of overkill here. Maybe if you wanted to program it to have an increasing blink rate and then turn off after X seconds, or maybe even have it automatically turn on the blinker when it senses the bike slow down and the handlebars turn past a threshhold rotation... but here, just find one of those blinkerbulbs and put it in series with the LEDs... instablink...
jongscx jongscx5 years ago
I meant the blinker-bulbs from the X-mas light strands... it's heat dependent, so your blink rate would go down with temp... but it's easier and cheaper than a microcontroller....
zascecs (author)  jongscx5 years ago
With all those sensors for heat and speed, that's a bit too complicated but I think that the X-mas lights (that blink) is a good idea. And why would I need a heat dependent sensor anyway? What if you just happen to be riding your bike on a really cold day and you still want the blink rate to be fast?
jongscx zascecs5 years ago
No, the blinker bulbs are by their nature heat-dependent. The main mechanism inside them is actually a bi-metal flap. When it heats up because of the current flowing through it, one metal expands more than the other, and causes the flap to bend away from the contact. Once it bends enough, the contact is lost, and the flap cools down. The cooling down unbends the flap, reconnecting the contacts... which causes current to flow... which heats the flap... [ad nausaem (*sp)]

Environmental temperature would play into this b/c the rate of cooling of the flap after it's been heated is directly related to the ambient temperature around the bulb. The colder it is, the faster the flap cools... the faster it can cycle... the faster the blink rate. Not many people notice this... well, because they're frickin x-mas lights. I'm just odd like that.

I wasn't saying that it was heat-based by design, just de facto due to the choice of components.

http://www.howstuffworks.com/christmas-lights2.htm
zascecs (author)  jongscx5 years ago
O.k., thanks. Just with the speed/turning sensor, what if you wanted to have the light turn on automatically, but if it were to turn on after the handlebars turned past a threshhold rotation, don't you want to turn the light on before you start turning but without changing direction because you want to inform the drivers that you're going to turn? And when you ride a bike, you often turn the handlebars to avoid rocks, for instance, or the path you are driving on is squiggly, so you can't go straight. So for that reason, having the turning sensor doesn't make much sense.
jongscx zascecs5 years ago
it was an example... because explaining "how to use an arduino to read the specific brainwaves that are emitted when a human wants to turn a bicycle a certain direction" was too long and would require an instructable in itself... Essentially, it's impossible to have the bike KNOW when you WANT to turn without you actually giving it a hint (the easiest being the turn signal lever). I actually took a comp sci class from a guy who was working on the Pilot Assistant programming for the F-22. It was supposed to be able to predict what the pilot needed based on his actions (ex: IF plane turns TOWARDS enemy aircraft, ENGAGE WEAPONS, IF plane turns AWAY from enemy aircraft, READY COUNTERMEASURES)... it required a bank of 12 or 16 computers (doubled for redundancy) to make it run... so while not impossible, it's bloody difficult. With the limited processing of the aruidino, the most logical alternative would be to program it to make generalities, such as "Every time A is X, then B..."
zascecs (author)  jongscx5 years ago
I wasn't exactly talking about the bike KNOWING what to do, just that the turning sensor wouldn't work.
zascecs (author)  zascecs5 years ago
(removed by author or community request)
well, it's currently not blinking at all, so I think thermally variable blinking would be an improvement over the current setup however you slice it. I would imagine the whole idea is somewhat moot for external heat sources since once the bulb or car blinker warms up enough to cycle once it'll be warmed up and cycle more or less the same as it would at any temp.
I thought so too, and it may still be true. I don't have evidence to support otherwise, except when I helped build an xmas float with my school. then again, it was bloody cold outside and my sense of time was probably skewed
That seems like over engineering to me. It'd be neat if you had the stuff around for it though.
zascecs (author)  carpespasm5 years ago
O.k., thanks for the advice.I'll try that.
luigi29995 years ago
you know, if you want them to blink you could use a resistor-capacitor configuraton in there, or you could use a 555 timer.
thompsonj5 years ago
Fantastic idea. When can we get one?
texpear5 years ago
I like it: low-tech, water proof and within a small budget. I like the way you are thinking about small, secondary details, e.g. using straws to protect wires on a handle bar. Schematic diagram is very helpful.
kica5 years ago
I like your presentation and attention to detail. You make it really easy to understand, especially for someone like me who doesn't know much about electronics. Maybe I'll give LEDs a try....
Notbob5 years ago
I like your idea of having them self-contained in a case. They do however, look a little dim in the video.
omnibot5 years ago
Cool. I like. Good lo-tech version of an indicator.