Introduction: Bike Light and Turn Signals

Picture of Bike Light and Turn Signals

Step-by-step instructions on how to build a rear mounted bike light with turn signals for day and night use, so drivers can see you and where you are going. All comments are accepted, I would like to hear ways i could improve this.

Step 1: Materials and Tools

Picture of Materials and Tools

-6 leds-color is a personal preference-Red/amber main light, yellow for turn signals

Don't use blue lights like i did, after making it i was informed blue is reserved for police

-2 mini-toggle switches
-1 Slide switch
-9v Battery
-9v snap connecter
-1 Project box-any size bigger than 4"x 2"-aluminum cover is needed
-1 Bic pen or Mechanical Pencil

-Soldering Iron
-Various Screwdrivers
-Wire Cutter/Stripper
-Hot glue gun

-Breadboard Wires

Step 2: Optional: Prototype on Breadboard

Picture of Optional: Prototype on Breadboard

Try Before building-use a breadboard. If you are not using a breadboard you may skip this step.

Step 3: Drill Holes for Aluminum Plate

Picture of Drill Holes for Aluminum Plate

Mark where the holes will need to be, on top of the box, having the plate facing away from the cover. Drill or ream holes so that the plate fits flush to the box. Screw the plate in-place with the thread of the screw is on the out side of the box.

Step 4: Mark and Drill Holes for Leds

Picture of Mark and Drill Holes for Leds

Take the four leds and make them in any shape, i made mine in a square. mark and drill the holes. also cut holes where the wires will run for the turning lights. Cut the Bic pen barrel in half, theses will be mounted on the sides and used to hold the turning lights. Also cut a hole large enough for the slide switch.

Step 5: Solder Everything Together

Picture of Solder Everything Together

Solder the components as shown in the schematic. Sorry for lack of pictures, i wasn't allowed to use the camera when i was soldering.

Before soldering the turning leds to the main components, solder on the main leads, and run the wires through the Bic pen you cut in half. Also before soldering the switches that will be mounted on the handle bars, drill a large hole in the top of the box.

Use only one negative wire for the 2 switches, to the handle bars, for the turn signals-at the end split it to two. Then from the 2 switches run two other wires bake to the leds. Also remember to cut the wires running to the handle bars longs enough that they will not limit your turning ability.

Step 6: Hot Glue Everything Into Place

Picture of Hot Glue Everything Into Place

Start by hot gluing the turn lights into the pen, so that they will be water tight. After that dries glue the pen halve over the holes you cut for the wires to run to the inside of the box. Now glue the four leds into their holes. After the Leds are in place and the glue has dried, carefully glue the slide switch into place making sure that the switch has enough room to turn on and off. Once everything is glued on screw the cover in place.

Step 7: Now Solder the Toggle Switches

Picture of Now Solder the Toggle Switches

After everything is hot glued in place take the wires for the turn lights and solder the switches in place. Also to prep the switches to be placed on the handle bars, take 4 mini zip-ties and loop one under the little tab used to keep the switch straight. in this zip-tie place a second one which will hold the switch to the handle bars. Do this to both of the switches. You can see how this is done in the second picture.

Step 8: Attaching the Lights to the Bike

Picture of Attaching the Lights to the Bike

Thread a mini zip-tie in each holes in the aluminum plate. Now tie the ties to the under side of the seat. After the zip-ties are firmly attached to the under side of the seat take a large zip-tie and wrap it around both posts of the bike seat and attach firmly. Now attach the two toggle switches to the handle bars in a spot where they are comfortable, for me it is one on each side near the grips. Attach the 3 main wires running from the switches to the part of the frame that holds the fork in place. Now Attach the 3 wires to the seat post and then up to the front part of the under side of the seat depending on the amount of slack you have in the wires.

Step 9: Using the Lights

Picture of Using the Lights

To use the lights you turn on the rear main lights, and when making a turn, like a car, you flick the signal switch in the way you are turning. For stopping you can also turn on both lights.

Step 10: Now Go Out, Be Safe and Have Fun

Picture of Now Go Out, Be Safe and Have Fun

Have fun riding your bike which now sports a new light and turning signals.


GeorgeP70 (author)2017-04-04

I am looking for signal lights for my bike that have stand-offs similar to those on a motorcycle.If you have signals on your bike here they have to be at least 600mm apart on both front and rear.Any help would be appreciated

ackra (author)2009-03-10

I recently purchased directional turn signals for my bike and the 1st day I used them they saved my life at an intersection where a truck was making a right turn. It's a no brainer. I purchased mine at I can't understand why I don't see more bikes with safety directional signals. Do you.

carpe_noctem (author)ackra2010-08-31

i signal with my hands, but i agree that signal lights would be helpful, especially at night.

Bryan Smith (author)ackra2009-05-30

One set is much cheaper here:

Brake lights, 8 different horn settings. and turn signals.

jman4647 (author)2009-09-13

Would you recommend this for a total beginner?

ElectricMan1 (author)jman46472010-02-19

Oh ya this is easy,
im making one that uses transistors to make the lights flash

jman4647 (author)ElectricMan12010-02-19

How would that work? I'm trying to learn all I can. I have a soldering iron, I can buy some leds, transistors ect.

ElectricMan1 (author)jman46472010-02-19

Heres the link to the schematic:

You need to be pretty good at reading schematics, soldering transistors and picking out all the parts. Im in HS and I taught myself to read these things so if you dont understand something, feel free to reply!

jman4647 (author)ElectricMan12010-05-08

"if you don't understand something..."

Lol, I don't understand any of it. I'm off to learn how to read schematics.

ElectricMan1 (author)jman46472010-05-09

O ok, ya its easy to teach yourself about schematics, I did, just use wikipedia.

You should actually order a kit off of a site called The Electric Goldmine, the kits run cheap (<5 or 10$) and come with schematics, along with detailed instructions in case you can't quite read schematics yet. You just need to have a good soldering gun and solder.

glorybe (author)2008-11-15

Hot glue and moisture won't work well together. I think the young man is doing fine but reading a bit about materials might help a bit. Bikes get soaking wet. Therefore just about anything for a bicycle needs to be really water proof.

jamar3030 (author)glorybe2010-04-16

 I made a bike light using hot glue and ride in snow and slush in Montana. I splash through puddles and mud. Light works fine even with exposed switches. Waterproof is for things that get submerged in water.

If you buy a bike light that claims to be waterproof, drop it in a body of water and watch it stop working fast. Most lights are only water resistant or splash proof. 

knektek (author)2009-11-04

this could be very useful for my mum when she's cycling (just because my mum is quite dangerous when cycling) thanks ! :)

rangeside (author)2009-05-26

By chance how many LEDs did you use for the main back light? and do you remember what the mcd rating was for them? Not too sure about that myself. Thanks

palle (author)2009-05-16

Very good idea...

shanealeslie (author)2009-05-12

If you get 'blinker' leds you don't have to keep flicking the switch for your turn signals.

shags1 (author)2009-03-10

Forgot to say: I'm building one of these for my electric bike. That is once I get around to building it. Again, Great job!

shags1 (author)2009-03-10

I'm very impressed. You have a very good form factor, not something most 13-year-olds would think about in the design. The reason for a resistor in series with the LED's is that it "burns off" the excess voltage that *could* damage the LED's. I don't think you'll ever get a voltage spike from a battery that would cause that to happen in the setup you have. But if you wanted to set up a dynamo to power the lights (along with a capacitor in parallel to level out any ripple volts and act as a "battery bank" (just pick one with a voltage above what the dynamo can produce and include a zener diode with a resistor in series with it to regulate the volts)) then the resistors would be necessary. The LED-series resistor doesn't have to be of high resistance; just make sure the watt rating is a quarter watt or over. Good job!

hartleymartin (author)2009-02-12

I think that this is a marvellous instructable you have added here. I have been pondering how on earth to mount the indicator LED's, and you've solved it! The only comment I would like to make is to consider making the indicator LED's yellow, as is convention with other road vehicles. Jolly great work mate!

jeff-o (author)2008-11-03

Pretty good, but here are some suggestions for Version 2: - Use AA batteries instead of 9V, you will get a much longer run time. - Add a resistor for each series chain of LEDs, or they will burn out - especially the turn signals! - seal the enclosure with silicone or hot glue. If you get stuck in the rain, water WILL get in and destroy everything inside. - as others have suggested, use red LEDs in the rear, not white or blue.

TFrosty (author)jeff-o2008-11-23

Why don't the LEDs burn out the instant they are connected to the power supply? Being foolish I connected one straight to a 9V and it blew. I thought you had to have a resistor so the LED didn't blow?

jeff-o (author)TFrosty2008-11-23

Well, the four connected in series will probably be fine, 9/4 = 2.25V which is just about right for the LEDs. However, the turn signal lights will almost certainly blow if you leave them on for more than a few seconds.

nsaltz94 (author)jeff-o2008-11-25

with the turn lights i have left them on for prolong time periods and they are yet to burn out but this could be do to the fact that i used color changing leds from a party light

nsaltz94 (author)jeff-o2008-11-03

-i originally tried it with AA's but it took too many to actually run all the lights -on the next one i will defiantly use resistors -i tried to seal the box as much as i could, but i couldn't seal the edges because i wanted to have it removable for the purpose of changing batteries or fixing wires -will change leds as soon as i get some red ones thanks for the tips

jeff-o (author)nsaltz942008-11-04

Well, it should only require 4AAs if you use a series/parallel combination for the LEDs - and as little as two for a fully parallel setup. You're right about the edges - how do you seal them and still make the lid removable? I know they make waterproof enclosures, but they're pricey. Hmmm, maybe a thin rubber band placed in the groove?

nsaltz94 (author)jeff-o2008-11-04

the rubber band sounds like a good idea or maybe a thin sheet of rubber like the ones for science experiments

jeff-o (author)nsaltz942008-11-04

Sure, anything waterproof that you can squeeze into that space between the case and the lid.

nsaltz94 (author)2008-11-18

i would greatly appreciate it if you would rate my instructable

matroska (author)2008-11-12

You're getting a 5 five starts from me. Brilliant concept, should be use with an alternator for the turning lights, so now you can really feel like you're a car.

ranger_steve (author)2008-11-07

the LEDs in the schematic are backwards

uberben (author)ranger_steve2008-11-07

That they are. This orientation might get some magical black smoke going on.

ranger_steve (author)uberben2008-11-12

haha lol

thatonekid (author)uberben2008-11-08

if you are referring to the schematic in step 2, the LED s are in fact oriented correctly with the Anode of the LED attached to the Positive lead and the Cathode attached to the Negative lead.

uberben (author)thatonekid2008-11-08

Ya, its been fixed now.

nsaltz94 (author)uberben2008-11-08

yea ill fix that

nsaltz94 (author)ranger_steve2008-11-08

sry i copied the leds from a page so i didnt have to draw them

thatonekid (author)nsaltz942008-11-08

go download express pcb, its free software for designing circuits and circuit boards.

Mekkie Boy (author)2008-11-06

For waterproofing: take a plastic sandwich bag (like a zip-lock bag) and cut the bottom off so you have a bottomless bag. Then glue the bottom edge of what you have left around the electronics in the case and seal it well with glue and/or silicone. Now everything is protected by the bag and all you have to do is open it to get to the electronics inside.

thatonekid (author)Mekkie Boy2008-11-08

though i have never tried, i figure you could also use silicone glue to make a bead around the rim of the box and then let it cure. that way once it's dried it will act as a rubber seal.

Mekkie Boy (author)thatonekid2008-11-09

True, but then you may have to re-apply it every time you opened the box.

roguefx99 (author)2008-11-08

Excellent prototype (whatever your age). Couple of ideas for a future build though. 3 AA batteries in series will give 4.5V which should be more than enough to run the leds and will last much longer. But the LEDs should be in parallel for that. I currently have a 9 led back light which runs for 100 plus hours and is very bright using 3 AAs. Weather proofing is always a problem a little silicon sealant round the edge of the box will help. You can usually get that in little tubes for use around sinks. On the indicators you could add either clear acrylic tube or drill out a piece of acrylic rod to put over the top of the leds to spread the light and weatherproof them. Last time I built lights I used a very small project box for the switches and put three 'push to make switches' in the top. After it was wired I glued a sheet of thin rubber over the top to completely waterproof them and put the box on the left hand side so I could use the switches with just one thumb. Something similar might help with your weatherproofing. I'll be looking forward to seeing your next project. :-)

idiosyncrazy (author)2008-11-07

Great job!

I would have chosen a different entry point for the wires and made the wires go into the unit from the back. Either that or made it so that the wires went underneath the metal plate that you placed on top of the unit. The reasoning for this is for better weatherproofing from water. The top entry would allow for easier stagnant water and/ or leakage into the unit. Although the top entry is acceptable if you do a good job in weatherproofing.

All in all, an excellent job! It's always pleasing to find creativeness in someone your age. I'll be looking forward to your future projects. =)

Greenehouse (author)2008-11-06

Great job, well documented and the photos help us understand what you are doing. Thanks. It seems rather fragile, what about using a metal tube all the way through the box for the turn signals? That would give it total support on both sides as it passes through the box...just a thought. Small holes in the tube center area would allow you to run your wires.

nsaltz94 (author)Greenehouse2008-11-06

you could do that if you get a big enough project box just mine was too small

lucek (author)2008-11-06

it just so happens I lost my tail light from my bike about a month ago. thanks.

MAcsSNAcs (author)2008-11-06

A solar recharger for the batteries would be a great addition to this.. then it would maybe never have to opened up again... thus getting rid of the problem with waterproofing it!

kelroy (author)2008-11-05

R = (VS - VL) / I

VS = supply voltage
VL = LED voltage (usually 2V, but 4V for blue and white LEDs)
I = LED current (e.g. 20mA), this must be less than the maximum permitted

kelroy (author)2008-11-05

you need to add some resistors in series with your leds else your leds will soon be dead

Notbob (author)2008-11-05

Awesome, i think i shall build a similar one to this once i get back to Canada, where my bike s stored.

rimar2000 (author)2008-11-03

EXCELLENT! If you have really 13 years of age, deserve a prize. (Si tú tienes realmente 13 años de edad, mereces un premio).

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