Bright Luxeon LED Bike Light

This instructable describes the construction of a bike light comprising three 3W Luxeon LEDs. This project had three main goals. 1.) Make a light suitable for use in 24-hour mountain bike racing. 2.) Use readily available material as much as possible. 3.) Offer the details to the community and invite any and all comments. I originally published this project at this site: http://www.racedaynutrition.com/features/bikelight.aspx

Step 1 Basic Hardware

Pictured here are some of the basic hardware items required for this project. On the left is a 5W halogen light from a VistaLite system (ca. 2000) from which the handlebar mount will be salvaged. At top are radio controlled helicopter motor or "280" size motor heatsinks. The other items follow the goal of using readily available material: 3/4" copper plumbing caps, 1" corner irons, and a 2" long binder clip. See Step #3 for a parts list.

Comments

[amdivoff]

if that is your garage im totally jealous! so much space,half of mine is taken up by boxes:(

[s3ntinel]

Awesome design - I based my 2 light design from this, plus a 3-pole 4-way rotary switch allows for wide, narrow, wide+narrow in parallel, wide+narrow in series (super bright off-road only - traffic will flash!)

Fitting into the copper cap was a little tricky, especially keeping bolt heads clear of lenses - I had to file down the bolt head and particularly the nut. I'm running a 10xNiCad 1800mAh C-cell pack (i.e. 1.8 Amp hours total), which does indeed give well over an hour, and fits nicely into a bottle cage. When the voltage drops too low for both in series (they dim considerably), it's easy to switch to a single bright beam with plenty of further time left. Saved huge amounts thanks to supply by a friend who services medical equipment!, but finding a charger for a 10 cell NiCad pack was harder (ebay).

Future upgrade would be to use NiMH or LiPo to reduce the weight.

My pictures on Flickr http://www.flickr.com/photos/49238647@N07/sets/72157623837257712/ - I've also added a bit more silicone sealant since then.

Top tips - don't pre-test LEDs without a heatsink - one lens came unstuck; drilling caps without a vice is painful...

[elinventor21]

 and u might want to make the leds weather proof maybe some type of protector and clear silicone or something just as idea

[elinventor21]

wouldn't i be able to use a micro puckbuck per led? 

[Jayvis Vineet Gonsalves]

I too have the same 15 degree lens but I don't undrestand how to open the lens? Could you please help me out.   

[marc92]

I'm hoping to build something similar to this, and I have a few questions. Because I would like to use a bike dynamo (at 6v, 3w, 500mA) to power this, I am unsure how to safely configure my 2009 Minipuck converter for maximum efficiency. It would be powering a single 1W Luxeon white LED. Can anybody help me out?

[biolethal]

you probably want to add a voltage/current regulator in there (and while you are at it a battery or a supercapacitor), because the minipuck probably cant handle the current and voltage from the dynamo when, for example, you are going down a hill. even if it has the ability to take a vareity of input voltages, just to be safe i would put a regulator in there.

[marc92]

Moreover, does the 2009A know what voltage to supply the LED's with, or is it a function of the input voltage? None of the documents I have read said anything regarding this.

[rodeobob]

If you use a centre punch to mark the holes and pilot drill with a (sharp) 1/8 or smaller drill bit you should be able to reproduce the holes accurately. Use an offcut of bar stock or pipe that the cap slips over mounted in a vice as an anvil.

[slindblom]

This is brilliant. I'm very tempted to build this, but I'm wondering if you could give some tips on how to set up the battery pack suitable for riding ~3-4 hours. Thanks!!!!

[pablosartor]

I made this light and run it off a 4.8v battery. made up of four AA NIMH. This lasts me about 1hr with the three heads going. I just finished making a battery pack eith 4 times the amount of batteries (still 4.8v). This should go for over 4 hrs easy.

[kwschofi]

Slindblom:
4 x AA NiMh batteries with >= 3000mAh should get you the 3-4 hours.

[pablosartor]

just made your light. It is amazing. good work. Drilling the clip is insane, drilled my finger twice. It was worth the pain THANKS!!!!

[elinventor21]

what did you use to power all of this?

[neuromonkey]

Would someone post the total parts cost for this project? I'm searching the listed sites for the parts, but it's taking a while to find them all. Poor or no search functions!

[elinventor21]

its all going to mount up to about $110

[krapez]

I ordered from ledsupply.com and payed with mastercard... all done in few seconds... all OK. For shipment i used Fedex expres... 3 days and package was in my country in Europe.

[lordofthedonuts]

I just oredred from ledsupply.com, don't pay with paypal, i ordered and they didn't redirect me to the paypal website to confirm with my password and username, I'm waiting for them to send me an email about my unpaid (or sohuld I say un-payable) order. If you don't mind paying by credit card, do so, it will save you a lot of trouble.

[QuackMasterDan]

I ordered from them and got the same problem, upon e-mailing them about the issue, they informed me to go the paypal.com and send a payment to [e-mail] for the total amount of my order. My order has already shipped and should be here soon. Hope that helps.

[lordofthedonuts]

thanks, I thought they were going to emial me, but it's probably better to be proactive.

[lfryling]

Any idea of roughly what you spent on this project? I've got some old BLTs that I could refurbish. I think it would be alot brighter with your system.

[Arnie1066]

NIce instructable, i might try this, but with lower power LED's. I'm not convinced your circuit diagram is correct though, it looks like your taking the +ve side of your supply voltage to the negative side of the LED's Is this a typo or something peculiar to these specific lights? ie normal LED wiring... (+) --|>|-- (-) sorry cant draw it better :)

[kwschofi]

Arnie- Good question. The LEDs and drivers in this build feature "buck/boost" wiring. Buck/boost wiring has inverting topology where the output voltage is of the opposite polarity as the unit. This configuration allows for a very wide range of input voltages. According to the ledsupply.com Micropuck applications guide (PDF), this Micropuck arrangement works well with voltages between 1 - 7 V. This comes in handy when you might be using your light for various applications requiring different battery packs. One drawback is that this configuration is less efficient than standard "boost" wiring.

[panstar1]

very good work ! there are drill bits that can drill through the metal clip ease ,it was called cobalt bit I had bought it for a few dollars. It takes the hassel of drilling through hard metals or a cement bit could work also. I used for drilling through some stainless steel ,very good stainless steel when i was making a knife a while back. the stainless I was using came from a band saw blade which was from a lumber mill. They had to use a plasma cutter just to cut the blade up , a oxy acet torch was not even hot enough !!!

[nelelr]

this is a dumb question. But can u use this technology to make a light for a car or truck heaDlight or wouldn't it go far enough?

[dll932]

Nice instructable, thanks! One thing I might add: acid core solder is for pipes and fenders. Rosin core is safer for electronics.

[Spokehedz]

Agreed. Your connections will likely fail as the water in the air combines with the acid to form pits on your copper. Or, you could clean it up with some alcohol. Oh lovely alcohol, is there anything you cannot do?

[dll932]

It is always good to preclean before soldering, but the function of flux is to help conduct heat and to keep air out, so there's no oxidation.

[Spokehedz]

Not exactly, DLL. But very close. Flux is there to help prevent oxidation that is formed when the metals in the solder and wire and/or circuit traces heat up. It also cleans off any oxidation already present on any of those materials when the actual soldering is taking place. And it also is a mild degreaser which cleans off the oils your fingers put onto the wire to allow solder to stick. I used to do a demonstration when I was teaching kids how to solder by taking a wire and cutting it in half. Stripping the ends off with a set of wire strippers, and then twisting the wires with my fingers in both hands. On one, I simply tried to solder wire straight to them. It would stick in some places, but not in others. That is the oil burning, and turning into carbon--which nothing will stick to. On the other, I would wipe a quick swipe of a flux pen--and the solder would stick perfectly. A lesson that they all could see, and they used flux ever since. For all my soldering work, I always wash my hands with a very strong soap--getting as much oil off as I can, so that it will transfer onto my projects as little as possible. But I am paranoid like that. :P

[dll932]

Well put-I stand corrected.

[kwschofi]

Crashing into rocks and trees encourages the connections to fail too. dll932 & Spokehedz - thanks for the advice. My next build will be done with Rosin core.

[chalky]

NOTHING SHORT OF GENIUS! You could actually make and sell these little baby's,i for one would buy one:)

[Hoochamajigger]

Be careful when applying arctic silver adhesive to electrical components, it is not electrically neutral. For a thermal epoxy that is electrically neutral and much cheaper, try Arctic Alumina adhesive from the same company.

[jmengel]

kwschofi- Hey, nice light. It looks like great minds think alike. I spent some time recently in the plumbing section of my hardware store and came up with the same 3/4" pipe caps for holding a LED star board. I wrote up an Instructable on the experience as well. In my case I used 3 Luxeon Rebels on a single star and enclosed the buck puck. Do you find that the heat sinks on your light get hot? Have you run the lights without the heat sinks? Did you glue the heat sinks to the copper or otherwise provide a thermal compound to fill any voids? I really wish there was some more fin area on those RC motor heat sinks. Thanks for sharing your project!

[kwschofi]

Yeah, I saw your light too. Nice job as well. The copper cap is such a convenient housing for the Luxeons, isn't it? Copper has high thermal conductivity and the cap provides protection for the diode and the optics. The aluminum motor heat sink does a decent job of shedding heat. It only gets warm to the touch. The heat sink fits tightly to a 3/4" cap without any mods like bending/crimping, but you could add thermal adhesive for optimum heat transfer. I'd probably use thermal grease just because I'd want to be able to remove the heat sink if the diode ever failed.

[omnibot]

Cool build. I noticed you have two wires from each LED, couldn't one be connected to common ground?

[profpat]

Great work! now i have some ideas for my mountain bike head light projects, my present led array head light is not bright enough...thanks..

[mdj817]

At this point, it seems like you're more blinding the drivers than letting them know you're there :-D

[TwoShort]

It is considerably more light than you need to let motorists know you're there. It is even more light than you need for seeing where you are going on pavement. The intro mentions 24hr mountain bike races; an environment in which there probably isn't anything that is too much light if you want to carry the batteries.

[jeff-o]

Nah, not even close. At a total 240 lumens, you're not even close to the 1000+ lumens produced by a car's headlights.