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Discussion Starter · #1 ·
I've just completed this dual Luxeon V LED bike light, similar in design to the 3xLuxIII I finished a few weeks back.



Once again I used one inch square aluminum tubing to construct most of the light. 20mm IMS reflectors are used, although I experimented with optics also.

I used a Downboy 750mA to drive the LEDs and a DPDT switch with center off to allow, one on, both on, or both off. It is powered by a 14.4v, 2500 mAH NiMH battery pack. One issue is that when fully charged, the 14.4v pack is over 16v which causes the DB to overheat (starts to flicker and freak out) it's designed for a max of 16v. I will probably replace the DB with a 700mA 3021 Buckpuck which can handle up to 30v input. It also turns out that I really like the dimming capability gained using the Buckpuck by just adding a 5k pot, and the Lux Vs will be a little happier at or below 700mA. I think I will like this better than the one or both on approach.

The light warms up within a couple of minutes if it's just sitting in the house, but on a test ride at about 10mph in the cool night air, it remained icy cold. The thermal mgmt plan for this light does not intend for it to be run for long while sitting on a desk... it is intended for night time trail riding and I usually ride 2 nights per week in the winter months.

Here is a link to some more pics of the Dual Lux V and a few beamshots: https://myfwyc.org/Timberlake/DualLuxV

Link to the construction of my Tri LuxIII bike light: https://myfwyc.org/Timberlake/BikeLighting?page=1
 

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Very nice job. I went back and looked at the thread for your other light, very nice as well. You've put forth some very useful and creative ideas. I'd like to ask your opinion on something. I enjoy DIY stuff and I'm reasonably mechanically inclined, but electronic stuff is pretty new to me and I am just learning. How difficult would you rate a project like this as far as researching/learning and completing the electronic portion of it? I have access to all of the necessary tools, I am just trying to learn the electronics aspect of it. Thanks.
 

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Discussion Starter · #4 ·
DaFireMedic said:
How difficult would you rate a project like this as far as researching/learning and completing the electronic portion of it? I have access to all of the necessary tools, I am just trying to learn the electronics aspect of it. Thanks.
The electronic portion of the project is fairly simple if you read around and do some research on the subject. It's basically just wiring/soldering a driver, the LEDs, a switch, and the power connector. If you pick an off the shelf LED driver like the 3021 Buckpuck, it's almost a no-brainer. There are some links in the thread for my TriLuxIII light that will be helpful. I'd be glad to answer any specific questions that you have and I'm hoping to build some web pages with more detailed instructions and parts lists in the near future. The thread on the TriLuxIII light is:
http://forums.mtbr.com/showthread.php?t=146529

BTW, I mounted the DualLuxV on my handlebars and the TriLuxIII on my helmet and went for a ride earlier this evening. I'm a little dissapointed in the light output of the DualLuxV, but it might just be that it spreads the light more. The TrixLuxIII light just kicks butt and I spent 1/2 as much on the LEDs in that light. Together though, they are nice! For a first LED light project I would definitely recommend a 2x or 3x Luxeon III project with a 1000mA Buckpuck (3021-D-E-1000). http://www.ledsupply.com/buckpuck.html

Run the thing easily with a 12v battery pack. Electronically, this is not hard.
 

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achesalot said:
The electronic portion of the project is fairly simple if you read around and do some research on the subject. It's basically just wiring/soldering a driver, the LEDs, a switch, and the power connector. If you pick an off the shelf LED driver like the 3021 Buckpuck, it's almost a no-brainer. There are some links in the thread for my TriLuxIII light that will be helpful. I'd be glad to answer any specific questions that you have and I'm hoping to build some web pages with more detailed instructions and parts lists in the near future. The thread on the TriLuxIII light is:
http://forums.mtbr.com/showthread.php?t=146529

BTW, I mounted the DualLuxV on my handlebars and the TriLuxIII on my helmet and went for a ride earlier this evening. I'm a little dissapointed in the light output of the DualLuxV, but it might just be that it spreads the light more. The TrixLuxIII light just kicks butt and I spent 1/2 as much on the LEDs in that light. Together though, they are nice! For a first LED light project I would definitely recommend a 2x or 3x Luxeon III project with a 1000mA Buckpuck (3021-D-E-1000). http://www.ledsupply.com/buckpuck.html

Run the thing easily with a 12v battery pack. Electronically, this is not hard.
Thanks for the response, and for the links. I have built a few NIMH battery packs and am getting familiar with soldering and some of the principles of electronics. I may take you up on your offer to help me with questions should I decide to try it. Thanks again.
 

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Discussion Starter · #8 · (Edited)
notenoughtime said:
Is the light water proof/resistant?
Yes. The light is sealed in the front lens with silicone caulk (although I had not sealed it yet in the picture shown), and where the body laps onto the light there is 1/8" overlap and a good dose of silicone based heatsink compound that not only helps seal out moisture but provides thermal transfer to help cool the LEDs as well. The switch and power connector should be able to keep water out as well, although they are not particularly weather or outdoor rated.... time will tell how they hold up.

So I would rate the light as water resistant. Waterproof to me implies that the light would be submersible... which it is not.

BTW, I had my first trail ride with this light last night. I used it in combination with the TriLuxIII LED light that I built about a month ago. The combo was awesome. I mounted the Dual Lux V on the bars and had the TriLuxIII on my helmet. It is a good combo becuase the DualLuxV provided a good amount of flood beam in front of the bike while the TriLuxIII provided a more concentrated, bright beam, where ever I looked. The temperature was around 55F and both lights remained cold to the touch.
 

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Discussion Starter · #9 ·
Well, I thought I'd post a follow up since things have been quiet lately.

After logging a dozen or so MTB night rides with this light (Dual Luxeon V LEDs) I've really come to appreciate it. I've done some experimentation and like having this light on the handlebar. I've attached a photo of my crude handlebar mount which uses a stainless steel hose clamp and some rubber backing to isolate and keep from slipping on the handlebar. It is adustable up and down.

As mentioned in an earlier post, I'd been trying out the combo of this DualLuxV on the bars, and my TriLuxIII on the helmet. I'm still riding with this setup and find it quite nice. Sometimes on slow trails I will just use the handlebar light, or dim the TriLuxIII to about 1/3 full output. The more spotlight-like output of the TriLuxIII can be a little distracting unless you need it to throw way down the trail (when going fast), so dimming it down lets it blend in better with the Dual LuxV which has more flood light, and less throw. Sometimes when riding at a more leisurely pace I just dim both lights to about 1/2 output. The batteries would last quite a while at this level!

Speaking of batteries, I'm using an old 2500 maH 14.4v NiMh pack for the DualV. I usually charge it between rides (which are typically about an hour) but sometimes I'll go two rides before charging... specially if I ran the light dimmed, as described above. I have another battery that is a 14.8v, 4A, Li-Ion pack. I've been using it for the TriLuxIII. I have gone 4 rides between charges, but typically I'll charge it every two rides. Both lights draw roughly the same power, so I could swap the batteries for either light. Eventually, I'll pick up another of the Li-Ion packs, as it is small, lightweight, and really kicks butt!

Both lights are holding up well. I've banged the TriLux on tree limbs a couple of times... no problems... but that is what you would hope for and expect from a light for MTB riding. I'm hoping to soon get some trail pics, comparing these lights to the HIDs used by many of my fellow riders. The LEDs are very comparible in output (especially when using both), and have other benefits as well.

Hey Walt, whats up with your Dual Lux V? Trail test yet?

Anyway, that's the update :)
 

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Nice!

Hi Achesalot,

Thanks for the info on your build. The comparison with the tri-Lux III is very interesting. I don't have a high output light to compare with. Since I am unable to make the comparison I can't say it's better, but I really like the spread of the beam with the Lux V and the 20 mm IMS reflector.

I used my dual LuxV for a commute yesterday. It is a vast improvement over my halogen 2x6 watt Cygo. Minus competing car lights, I could see about 50 feet clearly and 75 feet or more if the object was not too dark or low to the road. The spill is good enough to have a decent chance of seeing things like deer on the roadside. The light is bright enough (blue enough?) to see the spot when passing under a sodium street lamp, something that was out of the question with the halogens.

The Lux spot is roughly as bright as an auto's low lights out to about 10-15'. Of course the car's lows are just as bright out to twice that distance, and cover a much wider area, but the point is not that the bike lights are as good as car lights overall, but that they can compete succesfully in brightness on a smaller, still useful scale.

At one point, a driver starting a left turn across the street in front of me saw me coming and stopped. I didn't have to lock up my brakes to save my life. On the highway portion of my ride, my lights were bright enough not to get washed out in the car headlights, I could always see the pavement in front of me no matter what combination of traffic was competing with me.

Of the 4 drivers who felt compelled to nail me with their brights out in the country, 2 definitely dimmed when I aimed my lights into their windshield. The other 2 also dimmed, but probably because of a car behind me. More importantly, my lights were bright enough that I could see the road in front of me facing oncoming high beams.

For the first time, I feel like I'm readily visible to cars, and I can see well under all conditions at night. I'm hoping to get out on the trails soon.

I think I will soon have a winner for a helmet mount, I'll post again as soon as I have it done.

Walt
 
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