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DIY LED turn signals

26K views 34 replies 12 participants last post by  Combat  
#1 · (Edited)
I was going to post this in the 650r forum, but realized it's just as relevant for other bikes.

My integrated tail light started going out. Rows of LEDs were intermittently working. At the time i finally replaced it, only a few of the LEDs were actually working. :/ What a disappointment. LOL

Anyway, i decided to make my own turn signals.

I wanted them to be extremely visible. One thing i HATE about integrated tails is the turn signals aren't very visible. If I'm riding at the front of a pack and plan on turning, i want everyone behind me to know what i'm planning on doing. Signaling with a foot or hand isn't prudent in every situation. So i wanted the turn signal to take care of that.

I bought a few packages of LEDs until i found what i was looking for. I wound up using .5W 8MM amber super bright LEDs. They've got 140 degree viewing angle, and are bright enough to leave you seeing spots. So when you're getting ready to turn, the car behind you will definitely see it.

Enough jibber jabber.... Here's a video:

HOW TO:
If you want to do this as well, you'll need a few things:

1) LEDs - I used "Straw-Hat" 8mm LEDs. Straw-hat describes a type of LED with a dome-shaped lens which produces a more even light distribution pattern than the typical hemispherical type. Typically with a viewing angle in excess of 100 degrees.

The LEDs I used are yellow .5W Straw-Hats w/ 140 degree viewing angle at 95,000MCD with a forward voltage of 2.2-2.6.

I've done some searching online and there aren't exactly a ton of suppliers of Straw-Hat LEDs. However, ebay sells everything. I can't find any more of the ones i used, but did find some similar ones:

These are twice as bright as what i used. Might be overkill after dark:
Image
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390113432071&ssPageName=STRK:MEWAX:IT

These are almost exactly what i used, but take less power:
Image
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270696662932&ssPageName=STRK:MEWAX:IT

Obviously if you buy some of these, check their brightness and color first hand before continuing with your build. I bought several packs of LEDs before finding what i wanted.

If you're worried about longevity, the LEDs i used are rated for 100,000 hours. If you figure an average speed of 35mph, they should burn out about the time my bike reaches 3.5 million miles.

2) Resistors - What are the resistors for? Well, partly to bring the battery voltage down to something the LED can handle, but also to constrict the current flow. Current flow through LEDs is NOT linear. If the source voltage raises by 3 volts, the current across the LED may raise ten-fold. To force a linear current flow, you use resistors. This is definitely needed since your battery voltage fluctuates. To calculate the resistor you need, go here: LED Resistor Calculator

Don't buy resistors until you've settled on an LED to use. Different LEDs are gonna need different resistors. I made this mistake and now have an extra package of resistors sitting around that I'll never use. :/ Also, decide how many LEDs you want to use on each side. I used only one, but that doesn't mean you have to do the same.

3) Misc - Of course you'll need wire, solder and your basic electrical tools such as soldering gun and so on.

Instructions:
Choose carefully where you want to put these LEDs. Once you drill a hole, it's there to stay. These could go in rearsets almost as easily as tail plastics. I'm going to outline what i did:

LED placement
I removed my tail plastics and marked where I wanted to put the LED. I then reinstalled it to check that there was enough clearance on the inside to fit an LED and wires.

Once i found the right spot, I needed to copy this mark to the plastic on the other side. To do this I cut a piece of paper so i could form it to the curve of the plastic and copied the mark on the plastic to the paper. Then i used that paper to transfer that mark to the other side plastic.

You can't really use a center punch on your plastics so i took out my pocket knife and spun it like a drill bit to start the hole. I then used an air drill and turned the RPM's down as much as possible. If you drill too fast, you'll probably melt the plastic. Also, drill from the inside out where possible. Doing it the opposite way may cause your paint to flake off.

I also drilled the hole about half a millimeter too small and finished up with a round file. I'd recommend testing your technique on a junk plastic before doing it on a good one.

To hold the LED in place, you'll need to plastic weld it. Scrape the paint away from the hole on the inside of the plastic with a knife. Once fitted, put some plastic weld on the LED. It doesn't really take much, as it's really strong. Also try not to get it in the hole because if the LED ever does burn out you'll want to be able to replace it.

Here's a pic:
Image


After fitting it in place, you'll also want to mount the wire leads to the plastic with some more plastic weld for vibration resistance.

When i mounted the LED, i let the dome lens protrude beyond the plastic, but made the edge flush:
Image



The rest is just some basic wiring. Keep in mind when wiring this that LEDs are diodes and as such will only pass current one way. You can't hook them up backwards and expect them to work. Doing so won't hurt the LED (unless you're working with a lot of voltage), but it just won't work.

If you guys really need a wiring diagram i suppose i could draw one up, but it doesn't really seem necessary. Let me know what you need help with and I'll edit the guide as needed.

BTW, Here's a TIP: Plan on this being an all day project IF YOU HAVE ALL THE RIGHT TOOLS. The plastic weld takes time to set up. Don't rush it along. While my plastic weld was setting up, i did an oil change and a few other tune-up related things. If you're going to do this, be patient and TAKE YOUR TIME. THE END RESULT WILL BE DIRECTLY RELATED TO HOW MUCH TIME YOU SPEND ON IT!!! Don't rush, slow down and take some pride in your work.

If anyone is interested in a kit, feel free to PM me.
 
#8 ·
Mine wasn't negative...you americans are a sensitive kind aren't yah!?

I don't know how it works down there, but in Calgary we get fined if our blinkers flash too fast. Cops call it a distraction to other motorist and issue us a fix it ticket.
 
#9 ·
Dude, I've been riding the past two months with NO tail lights and haven't been pulled over. I've never been pulled over for my signals flashing too fast. If i did, I'd just tell the cop it "came that way". Lol.

Not to mention, I'm sure the lights themselves aren't legal. But who cares? Everything is illegal. For example: In this state it's illegal to use your horn. They call it "aggressive driving"!!!

My buddy has a "pass" button that comes stock on his GSXR. When you press it, it flashes the headlights to let cars ahead of you know you're passing. Also illegal to use.

So I'm really not worried about flash speed. I'd rather it be a distraction for other drivers because at least then they'll see me and hopefully not run my ass over.
 
#15 ·
make this a detailed how-to with links to resistor calculators, materials and all the little details, and i will link this in my how-to navigation thread.

do it, or i will call you bad names and end up doing in myself.
 
#17 ·
make this a detailed how-to with links to resistor calculators, materials and all the little details, and i will link this in my how-to navigation thread.

do it, or i will call you bad names and end up doing in myself.

Hahaha. Ok, ok. Tomorrow I'll try to take some time and do a decent write up. Although i may be lacking in some pics as i was focused on finishing the job rather than cataloging it. :)
 
#26 ·
Sweet Combat! Thank you for taking the time to do the write up! Gotta few questions though, I'm confused about the resistors. In your video the blink rate is fast, do you have resistors hooked up at that time? I thought the resistors slowed down the blinker rate. I bought one of these to use for my leds, Custom LED Electronic LED Flasher Blinker Relay - Plug And Play . Would I still need resistors?
 
#28 ·
Sweet Combat! Thank you for taking the time to do the write up! Gotta few questions though, I'm confused about the resistors. In your video the blink rate is fast, do you have resistors hooked up at that time? I thought the resistors slowed down the blinker rate. I bought one of these to use for my leds, Custom LED Electronic LED Flasher Blinker Relay - Plug And Play . Would I still need resistors?
I do believe its the relay that controls the flash rate.. since the led's draw so little power, the stock relay thinks the light is burnt out, so it flashes quickly.. just like a car would. your relay would make it flash properly..

a resistor wont make the light draw any more power. It reduces the amount of power the led is getting from the battery.

Someone correct me if im wrong.
 
#35 ·
Well i was cruisin down I-5 at about 80 when a tan GMC SUV blew by me at around 15mph faster than i was going. He pulled in front of me and slowed down. I was like, "WTF?". So I dropped a couple gears and hit the gas to get by him in a hurry. Passed him at around 110 maybe a lil more.

Turns out it was an unmarked cop. I checked my mirrors a few seconds later and saw the familiar red and blues. As i pulled over i was just hoping to stay out of jail for the night. I would have been content with a huge ticket and my driving record no longer being clean.

I pulled over, and started removing my gear (gloves, helmet). When i got my helmet off the cop was standing beside me on the other side of the guard rail.

"What's the speed limit?", he asked.

"70", i said.

"And how fast were YOU going???", he asked.

I've got a policy of not incriminating myself so i said, "IDK, i wasn't watching my speedo i was watching the road."

So the cop says, "If you're gonna ride one of these motorcycles, you've gotta pick your spot. I-5 isn't YOUR spot."

So i said, "Yes, sir."

He said he'd pulled in front of me to slow me down and keep me out of trouble. He asked for my license then returned to his vehicle.

He emerged about a minute later and said, "Have a nice day."

Needless to say, i was stoked. Said, "Thank you." and off i went.