Introduction: Bicycle Turn Indicators

About: Ham Radio, Gardening, InfoSec, Bicycles as transportation -- Currently: Product Security @ Slack

Being a bicyclist in the East Bay is a hard task at times with drivers who don't know how to signal and being yelled at to "get out of the street and on to the side walk" (even though it's illegal),

Whats even harder is attempting to warn drivers when you are going to turn. You could throw your hand out, but this can make you loose stability and most people don't remember the ways to put your hands. This instructable seeks to make warning drivers and other cyclists that much more easier, and make your more visible while doing it especially at night.

Alas this is the premise for the Bicycle Turn Indicators, another pal in the "Make Your Bike Into A Car Series"

Step 1: The Flashing Circuit

When first considering this project i thought of all kinds of ways to make lights flash from using an arduino to a 555 circuit to the circuit Kipkay uses for his LED Fan Sign My Friend and coworker JacobAziza mentioned that he had to change out his mechanic relay on his car and motorcycle to run it of LEDs. PERFECT! why build a circuit from scratch when the circuit already exists for automobiles?

A note about flashing circuit relays for cars, There are two kinds electrical and mechanic. Make sure you pick up an Electrical one, i made this mistake, and got the right one off ebay. Below are some pictures.

Step 2: Choosing Battery

Choosing a battery for this project was an issue of weight vs. cost. If cost was not an issue i'd be throwing a Li-Ion pack on here and it wouldn't be a issue. It's much the case that good priced rechargeable batteries are low in amps, so they discharge quickly. My suggestions for this project are the following:

A few D (8000mAh) NiMh batteries equaling 12v (Slightly Expensive but will last quite a while)
12v Lead Acid (Heavy as hell, really cheap)
2 Lantern Batteries at 6v each (Not Rechargeable, boo)

for this project's longevity, go with a rechargeable option. If you have a lot of amps you could also run a car horn or a small sound system.

Step 3: Supply List

To get you started here is the supply list:

1 LED flasher (Electrical NOT Mechanical)
1 12v battery (Choose Wisely)
20 Yellow 10mm LEDs (yellow is the standard on cars, you could use anything but blue, blue is illegal on vehicles)
4 82 OHM resistors (Based on the calculator here
A way to Case it (i'm using Beta cases due to their flatness)
Connectors to allow the cases to be removed from the bike (i'm using auto cables)

Step 4: Test Circuit #1

First off to test my idea i threw together a quick test circuit, this allowed me to see how the flasher works and how bright the lights are. I strongly suggest breadboarding it out first so you can catch any mistakes.

Step 5: Test Circuit #2

After the simple circuit worked, i decided to breadboard the circuit i got from the LED calculator....

Step 6: Creating the Blinker Cases Step 1

Next after all the prototyping is done, you want to make the cases. I used Beta tape cases just because they are a nice size and have a small profile. you could use almost anything for this.

Step 7: Creating the Blinker Case Part 2

Next you want to mark where you want to drill the holes for your leds, and then drill the holes. This was not too hard, i used a power drill.

After that, check the leds and see if they fit, if they don't drill out the hole a bit more, I made my holes just small enough for the leads but not the whole bulb.

Step 8: Creating the Blinker Cases Part 3

Once you push all the LEDs through, you can start soldering them together, In series. Then attach the Resistor to one end of the series (i did the negative end).

Last use a connector and solder that on so you can plug it in with the rest of the system. Use hot glue to make it all stay put.

Repeat 3 times.

Step 9: The Switch

Once you are done with the cases for the LEDs you need a way to swtich them. I'm using an on-off-on switch and a small project box. I will be hooking up each side of the leds to each on switch so i can turn on the side i am turning towards.

I dremeled out a plastic case and attached zip ties so it can be attached to the handlebars.

Step 10: The Relay Case + Batteries

The wiring just hanging out all over the bike would have looked really messy and probably get broken so i cased all the wire connections and the relay in a 5th Beta tape case. The wires get really confusing at the point, be sure to keep track of what side is left and what is right so you hook them up right.

The Batteries on the other hand are a bit to big to go in this case so they are getting strapped the bike with zip ties

Step 11: Installation

After you are done with all the parts, install the cases and the batteries to the bike, i used zip ties. Once all the cases are on you can wire it up.

The first step it too attach the light cases, i drilled holes about the size of the fork and down tubes and attached them with zip ties.

next attach the switch and solder 3 wires to the switch which will control the direction of the turn indicators.

Lastly solder it all together, remembering which size goes to which switch, i used a little piece of tape to remind me.

After all the wires are soldered, do a battery check to see if everything works, if not check your connections. Once that is done you can attach the batteries and hook that up with the rest of the system.

This step takes about 2 hours. Be prepared and it also makes your bike unoperational for that period.

Step 12: Test Ride!!!!!!

Once you're done, TEST IT OUT!!!

I was really impressed with the brightness level and it seemed to help maneuvering around automobiles.

The first problem i encountered was that i hit the back light fixture with my foot, Also the general size of the light fixtures are a bit big, a smaller container could be used.

The zip ties also proved to not to have a good enough grip from preventing the light box from moving from side to side, this could be fixed by using hose clamps, which i will get in the next few days.

Putting in a way for both lights to be flashed at the same time would improve this project thus allowing for a "warning light"

Here is video for the final product:

Get the LED Out! Contest

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