Looking to build an LED bike light...Can I have a hand please?

[mc_nebula]

Hi there, my name is Ali. I have been lurking on and off here for a while, mostly just gawping though

Anyway, I have been looking to build an LED bike light (handle bar mounted) for quite some time. However, the problem I have is this: There is such a lot of info out there and such a lot of different alternatives that I have absoloutly no idea where to start!

I am comfortable with starting from scratch and making something like this guy http://myfwyc.org/Timberlake/CreeLEDLight but I have no idea where to start or what the best combinations of LED's (in terms of wattage, lumens/candlepower and number) would be. I also have no idea/cannot fathom buckpucks, downboys or whatever the hell those things are...

Oh, and batteries, what is good? Fancy Li-ion ones need specialist chargers, right? But it is possible to use a load of 2700/3000mAh AA's right?

Oh, and I have a budget, around £40. :eeksign:

So, anyone want to help me?

Cheers!!

 

[MtLuke]

That's a good place to start, I built one of those myself and they work well.
Lumen wise, you should be able to get about 600 or so using a 1000ma driver.
If they are handlebar mount use 2 wider lenses and one narrow(2 CRS-Oval-1 CRS-diffussed). For helmet mount narrow it up and get 2 CRS-RS, 1 CRS-SS.
Use the "LEDpro" program to figure run times and such.
I just used a premade 14.4 pack using AA batteries.You can find them on Batteryspace.com or All-Battery.com. NiMH work fine and are inexpensive.
Use a 3023 Buckdriver from LED supply for simplicity, and make sure you get some decent connectors, Deans or Trailtech(M series at RadioShack).
Other than that just follow the directions and you should be good to go.

Eric S

 

[carbine15]

 

[FrontRanger]

That may not be quite what the OP meant...

mc_nebula, you didn't mention what kind of riding you're doing, but before you start with the assumption of battery power, have you considered using a dynamo? Martin's site (pilom.com) is an excellent resource. Just a thought, and probably outside your stated budget, but it might be worth considering.

 

[mc_nebula]

I'm doing road riding, mostly. However, it's split beteween city and countryside. So I am looking for something quite bright. Handlebar mounted is great...

I have A-level electronics and I am good with my hands (dremel etc.)

So, there are a couple of things which are mysteries to me... -

Lumen wise, you should be able to get about 600 or so using a 1000ma driver.

What is a driver? What is a good one? Where can I get one in the UK?

premade 14.4 pack using AA batteries.

do you mean a 14.4 volt battery pack? I assume you do?

Use a 3023 Buckdriver from LED supply for simplicity, and make sure you get some decent connectors, Deans or Trailtech(M series at RadioShack).

- What's a Buckdriver? What is it used for? How do I wire it in?

I am a total n00b to this...Go easy, please?

I'm not asking anyone to do this for me, just to help guide me through it. Most of the guides online for building these are aimed at experienced people or are 2002-2006 in age. I guess stuff has moved on since?

Cheers guys!

Ali.

 

[dnlwthrn]

I'm doing road riding, mostly. However, it's split beteween city and countryside. So I am looking for something quite bright. Handlebar mounted is great...

I have A-level electronics and I am good with my hands (dremel etc.)

So, there are a couple of things which are mysteries to me... - What is a driver? What is a good one? Where can I get one in the UK?

do you mean a 14.4 volt battery pack? I assume you do?

- What's a Buckdriver? What is it used for? How do I wire it in?

I am a total n00b to this...Go easy, please?

I'm not asking anyone to do this for me, just to help guide me through it. Most of the guides online for building these are aimed at experienced people or are 2002-2006 in age. I guess stuff has moved on since?

Cheers guys!

Ali.

First things first:

Drivers - what we're talking about is a small IC circuit that is designed to output a constant current to the LEDs. There are two types generally available, the buck driver and the boost driver. The buck driver is used when your power supply has more potential than the forward voltage of the LEDs you're using. The boost driver is used when your battery has less. So if you're using 3 LEDs in series (and I'm using Cree XR-E Q5s for my example, cause that's what I have here), your Vf (forward voltage) will be approximately 11.1V when running 500mA through them. If you want to run a buck driver, you should have a power source that is at least 1V greater than your total Vf. If you're running a boost driver, the power source should be at least 1V less than the Vf.
So if you use the 3023 Buckpuck driver, your best bet would be going for a 14.4V battery pack (whether pre-made or individual cells in a holder).

As for suppliers, there are plenty. It really depends on where you live. LED Supply was mentioned above, and can get you pretty much everything you need. Cutter is another, located in Australia, that has pretty much all you need. Lots of people have been using Dealextreme or Kaidomain (both in Hong Kong) as a cheap source of LEDs and parts. Sandwich Shoppe is listed in the CPF Custom Builders and Modders forum, and carry quite a bit of what you want. So start looking around and see what you can find.

As for the guides written from 2002-2006, a lot of the info is still good. You just need to find out what's new with the LED technology and adjust accordingly.

 

[Jarl]

As for the guides written from 2002-2006, a lot of the info is still good. You just need to find out what's new with the LED technology and adjust accordingly.

+1. Generally speaking there hasn't been much change in drivers over the past couple of years.

My setup is 3 LED's, a 3023 buckpuck and a 14.4V home-made NiMH battery pack. It's switched to allow 0,1,2 or 3 LED's to turn on, cost about £120, though that did give me some extras to play with. I used www.ledtech.de for LED's and connectors.

 

[houndlegs]

hello ali
i`m in the same boat as you and its confusing the hell outta me, but theres some good advice in this guys website http://www.bikeled.org/

i`m beginning to think though that i simply dont know or understand enough about electronics to try it myself

i certainly dont mean to hijack this thread, but if anybody wanted to write up an idiots guide to all this, i for one would be most grateful

good luck ali
phil

 

[FrontRanger]

hello ali
i`m in the same boat as you and its confusing the hell outta me, but theres some good advice in this guys website http://www.bikeled.org/

i`m beginning to think though that i simply dont know or understand enough about electronics to try it myself

i certainly dont mean to hijack this thread, but if anybody wanted to write up an idiots guide to all this, i for one would be most grateful

good luck ali
phil

Howdy Phil,

:welcome:. As you can see, there's more than enough info here on CPF and elsewhere on the web. Here is a super-short, high level view of the basics of building a bicycle headlamp with modern power LEDs. There are four aspects to the design: electrical, mechanical, optical, and thermal.

Electrical: First you need a power source, either batteries or a dynamo. Li-based batteries have high energy density, and NiMH are cheaper and more tolerant of charge/discharge abuse. If it's a dynamo, see pilom.com. The LEDs should be a driven with a constant current (as opposed to a constant voltage). The circuitry that performs this is called a driver. Dynamos already act like a constant current source of ~500 mA, so many people make use of this fact. Batteries act more like a constant voltage source and need additional circuitry to convert this power source to the required constant current.

Mechanical: You must find a way to attach the lights that can tolerate vibration, range of motion, fine adjustment of the beam angles, and if required, be easily removable.

Optical: If you're doing the work to make something like this, design the optics for your type and style of riding. Many people mix a spot-type beam with a flood-type beam. Some modern rigs are so bright that the distinction isn't needed!

Thermal: You must provide a thermal path for the heat to get out of the LEDs and any other lossy circuit elements. Ambient temperature and the drive current you choose are the primary determinants of how hard or easy this is.

Note that many of these are inter-related (e.g., very often the mechanical support is also the thermal path; or, the height of your mount with respect to the ground may affect the beam pattern you use, etc.)

Do a lot of reading here, don't be afraid to spend a few coins at DX or KD, and good luck!

 

[yellow]

I have built Led-lights when there were no good makers (= only very expensive)
then entered FENIX

Sure building a light for You own is nice, the en product will be worse, more expensive, much more work and looking way less good, than a simple small 2AA/18650 torch, mounted to the bars by homemade holder (because there are not too much good ones).

Get Yourself a Fenix L2D / LD20 (new model), when You want to use AA rechargeables (and dont use anything less than Eneloops or similar "precharged rechargeables", normal Ni-Mhs are wores, no matter what number is printed on),
or, if You want the 18650 Li-Ion route (the better route!), look at the Jetbeam Jet III models.


Sure You still can build Your own light.
imho the best idea is to get a light from dealextreme --> using it as a HOST
That way You have a nice looking housing - better than any homemade one - and all the parts for it: glass, seals, ...
Now think about brightness (number of led) and runtime (size of battery) and decide what to use.
Then, when You know Your battery an number of led, think of driver (step-up or step-down)
... You could ask again then.

Easiest: get one of the multiled lights and use just the head, simply mod the back of it with connetions for Your batt pack.
expert: use just head and inside heatsink, mount better aftermarket parts: led, focusing devices, driver, level choice (switch) and connetors


imho the Fenix LD20 / Jetbeam Jet III way is the better one.
At least the one You get lights offering more than just on application they shine - You ca still use them what they are built for: portable lighting

 

[dnlwthrn]

Sure building a light for You own is nice, the en product will be worse, more expensive, much more work and looking way less good, than a simple small 2AA/18650 torch, mounted to the bars by homemade holder (because there are not too much good ones).

(snip)

Sure You still can build Your own light.
imho the best idea is to get a light from dealextreme --> using it as a HOST
That way You have a nice looking housing - better than any homemade one - and all the parts for it: glass, seals, ...

Hmm. You know what they say, opinions are like A$$holes, everybody's got one.

Have you seen some of the DIY lights that people have been making? The Fenix lights are great, but show me one that will give me the output I want and the runtime I need. I have yet to find one. Also, most LED torches tend to be WAY too focused (i.e. not enough spill) for what I need. For a helmet light, yes, but not a bar light and not by itself.

The other thing to remember is that DIY is a HOBBY for many of us. That means that we aren't as concerned with making a "perfect" looking housing and we enjoy tinkering in the shop...

 

[FrontRanger]

The other thing to remember is that DIY is a HOBBY for many of us. That means that we aren't as concerned with making a "perfect" looking housing and we enjoy tinkering in the shop...

+1. I may well have the ugliest bicycle headlamp on CPF, but the output (while not perfect) is better than all of the commercially available lamps I've ever owned, bicycle-specific and otherwise. And it was also cheap to build.

 

[green814]

There is a thread over in the light forum on mtbr.com that has a Dinotte style light for about half the price depending on what host/ led/ driver/ battery set-up you go with. http://forums.mtbr.com/showthread.php?t=368896 21 pages of info to surf through.

I was looking at building one myself with parts from Cutter, Cree R2 driven at 1a, but is there a place in the US that I can order everything but the host from? I plan on using the 9led flashlights from DX as a host.

Chris

 

[Charlotte]

I'm a n00b to CPF and this thread drew me in like a bee to a honeypot. I'm a long-distance road cyclist and I'm currently using a mixture of SON Dynohub powered LED lights (Solidlights) and a Fenix P2D as a backup.

I'd love to be able to spring hundreds of pounds on a Lupine or something equally daft, but until I can, I'm really interested in the possibility of a home-built setup. I can justify about £100 in parts, I'd have thought.

I even have a pair of E6 halogen lights that are just begging to be modified to take some modern LED components, if that's a possibility.

The posts above have been really useful in understanding what I need to build a system, but if some kind soul feels like helping me further; that would be grand.

 

[Eamon]

I'm a n00b to CPF and this thread drew me in like a bee to a honeypot. I'm a long-distance road cyclist and I'm currently using a mixture of SON Dynohub powered LED lights (Solidlights) and a Fenix P2D as a backup.

Start here:
http://www.pilom.com/BicycleElectronics/BicycleElectronics.htm

and here:
http://bikeled.org/

Martin has put together a number of different functionalities for dynamo-driven lights. I've been running his circuit #10 for several thousand miles now w/o issues. Several other people with Dynamo setups report similar results.

I'd love to be able to spring hundreds of pounds on a Lupine or something equally daft, but until I can, I'm really interested in the possibility of a home-built setup. I can justify about £100 in parts, I'd have thought.

On the assumption that you would like to stick with your SON, your budget is quite reasonable. Most of the parts are very straightforward and easily available.
Different people build different solutions, obviously. Anything I build for brevet use must have all the electronics, emitter(s), optics, and switchgear in the same housing. I'm building a second version of Martin's circuit #10 that will fit everything into a tube 35mm(ID) x 100mm. Other people are quite comfortable with a small unit on the handlebars and a separate electronics unit. Different lunatics, different solutions.
1) Does it work? (yes/no)
2) Do you like it? (yes/no)

I even have a pair of E6 halogen lights that are just begging to be modified to take some modern LED components, if that's a possibility.

If you like the controlled beam of an E-6, and want something similar, you might think about something using B&M's indirect reflector. The Edelux, IQ Fly, Ixon IQ and a couple of others all use it. There is no aftermarket optic that I am aware of that offers close to that degree of beam control. Most of the homemade/modified lighting that I've seen, including my own, is in violation of EU lighting guidelines.
Terralux sells this:
http://www.terraluxcorp.com/products/TLE1.php?PHPSESSID=d3c288fe8707717d8f1f5d6d709b8071
There may be other conversion emitters out there, and I have no idea how well this would work in an E-6, but it's cheap-ish experimentation.


The posts above have been really useful in understanding what I need to build a system, but if some kind soul feels like helping me further; that would be grand.

Have fun, there is lots of knowledge on this forum and all sorts of interesting design solutions.

Eamon

 

[yellow]

The other thing to remember is that DIY is a HOBBY for many of us. That means that we aren't as concerned with making a "perfect" looking housing and we enjoy tinkering in the shop...

-1
when I build lights, they both have to better than shop-bought ones and AT THE SAME TIME have to be better looking, or, at least, the same.
If that homemade light is easily spotted to be homemade, then one should work on the finish.
All my lights are built that way and achieve the goal
(and I dont call myself good at working with my hands)

when considering all parts to get for a housing and the work on machines (if one is lucky enough to own some, I dont), purchasing a cheap light on DX and using just its head as housing costs the same, makes less work, gives long term useability and a nice looking "product".
Even when Your "rugged" homemade light is better than the purchased ones, You will still get some sayings from other ppl, even when they are jokes - just a bit of planning before starting the work and one rides the bomb, without any negatives (effort, price, difficulty, ...).
To say it straight: just because a light is homemade it does not have to look like crap. When put into a 20-30,-- light head "housing", already w. front glass, O-rings, anodizing, ..., such a light simply looks good.
Did I already mention the time safed by not having to do mechanical work on a plain pipe found for the project? On the aluminium sheet planned to mount the led(s) on? Thats all there already.
If its ok with a tight beam, simply use the complete head of the DX light in question and put a cable (+ end plate + switch) at the back end of the head leading to Your batt pack. Drill hole into housing for a holder and mount it to the bars.

PS: yes, I have also built some lights already, I consider it an important hobby of mine. Many of the ppls around me get them. It does not add complexity or cost to make nice looking lights, it decreases work.
Also both members asking questions sound like total new guys into the field and the idea of mounting the flashlights is the quickest and cheapest way for them to get to a working light during this winter.
Eventually the "just use the head alone" idea might give similar results, with a P7 light maybe?

 

[yellow]

Charlotte,
Your hub is about the best things to use, especially when You ride long, stay with it.
Modding that Halogen light is very difficult, not use the hassle. If You want I could post pics of a modding idea.
Have You done measurements of the Hub? With the dynamos I know three led in series are the best compromise, I have no data for hub.


an idea were to use something like this here: http://www.dealextreme.com/details.dx/sku.14029
as typed in the post be4: use just the light's head, remove all electronics inside, connect the led in series, add Your rectifier driver, put a hole inside to mount holder for bars, make an end plate to cover the hole at the end, put on bars, connect to Your hub, done.


on the road the thight beam might be a plus. If You dont like it, remove the mounting/thermal plate and led and scrape the new spots to mount the led(s) again with a few degrees angle. That way the individual beams are not parallel and You receive a wider, triangular main beam.
A bit of work for much improved, wider beam.
Unfortunately You will possibly loose the original led and the triple-reflector will also be of no use then --> get optics instead
(they tend to give a less bright spill light, better for on road lighting)



My pesonal favorite rectifier/driver is JürgenH's MOSFET,
for me it is better than any other circuit I have built till today, even very difficult ones.
(when You get the small parts and are shocked about their size: it is doable)

PS: there is a quick thing to try on the Schmidt: put a more powerful bulb inside.
6 V / 800 mA, 6 V / 1 A is something available relatively easy
but (there is always a but): needs more power from You, runs HOTTER
(and I mean hotter. I have have several of such (but cheaper) headlights fail because the other bulb melted itself out of the plastic housing


PPS: what do these solidworks cost? They look bulletproof but awful. Like those typical "homemade" lights.

 

[Charlotte]

Eamon and Yellow - thank you so much for your replies

I've just taken delivery of one of these for my SON:

It's a B&M IQ Cyo and at 60 Lux, with a really good reflector, it's about as good a light I think I could ever hope to build myself.

What I'm concentrating on for my home-build is a battery system. A friend of mine has just told me that he may be willing to part with an old Lumicycle HID housing with a blown bulb. My current plan involves trying to shoehorn in one of the XR-E MR11 kits that Cutter sell.

Mind you, for £160, Lumicycle are selling their new LED light, so whatever I do had better be brighter and cheaper than that, or it won't be worth it...

Any thoughts?

 

[rufusbduck]

"My current plan involves trying to shoehorn in on fo the mr11 kits that cutter sells."

Good for you! I'm trying to do the same thing with some vistalites. I'm using three Cree R2's on the triple mr11 pcb ( altered to run the leds in parallel) with the khatod triple optic(it's ~2mm shorter). I bought one of each of the optics and the flood is useless except as an area light, the medium is still floody but good for a bar light(short range), and the narrow beam is ideal (to me) for a helmet as it will light up th whole fireroad at a range of 40' to 50' ~15meters. The old vistalite lamps had too tight a spot and too dim a flood.