Big Light Prototype

[StevelKnievel]

Here's a little something for those 4-5 hour epic backcountry rides with 40mph downhill sections. My goal with this light was to develop a light that's very efficient with long runtime at ~700 lumen and also provide 1500+ lumen when needed.

This light has 10 Q5 WG emitters and I included 3 red emitters to improve color rendering. Next time I think I'll use 3 amber emmiters instead, this one is a little too rosy for my taste. Driving everything at 600mA it should be putting out ~1800 lumen and consuming around 25W. The housing is 2.5" OD and 2" long and weighs about 250g complete. I made the wall thickness pretty thick on the housing and the optics are behind 1/4" Lexan, so this light should be indestructable!







Beamshots will be coming soon. The light is with a friend of mine at the Icycle race (link: http://jandwevents.com/info.html ) in Fontana, NC right now for some night DH racing action. When he comes back I'll do some shots comparing the effects of the red emmiters with amber ones.

[HEY HEY ITS HENDO]

MWAHAHAHAH .......... Superb!
... Is there any heat issue at 600ma?

[StevelKnievel]

I'm driving with a maxflex, so thermal protection is there if it does get too hot. In 75deg F ambient still air, maxflex thermal protection set to 60deg C, the light will step output down after 7 or 8 minutes. When outside walking around the housing got quite warm but didn't ever have to step down. The driver is thermally connected very close to the LEDs, so Tj shouldn't be getting much above about 100C if my math is correct. The fins on the back of the light give pretty substantial surface area and heat up fairly evenly.

[Tidra]

How many MaxFlex drivers do you use in this light and what typ of optic do you use?

Thank you
Iztok

[Zero_Enigma]

How much are you looking to sell the first batch at? Also what's the count on the first batch run? Man seriously, www.MEC.ca needs to get in touch with some of you builders out there. Perhaps some higher volume buys can lower the overall cost.

[Krit]

My Imaginition is a very bright light drive thought the road and every one think that a big truck is comming. :-)

[StevelKnievel]

Beamshots are coming! I just got the light back and I'm going riding with it tonight, so I'll take some pics.

Tidra-
I'm using 1 maxflex to drive two strings of emitters. The lower vf of the red Cree XRs allows one string of 6 XR-Es and one string of 4 XR-Es and 3 XRs. I'm using Polymer Optic part # 170 and 171 for the optics. I'm still playing around trying to find the optimum spot/flood arrangement. Right now I have 6 XR-Es with 6deg optics and 4 with 25deg optics, 2XRs with 6deg optics and 1 with 25deg optic. I'm looking forward to building the next prototype with amber XRs instead of red, right now the light is too pink.

Zero_Enigma-
First run will be very small, maybe 20 lights or so, but we're still going to try to beat the price of the Lupine Betty by a fair bit. I don't have exact pricing info yet, but I'll keep you guys updated. I expect to have the lights in stock around mid-March. Francois from MTBR forums is getting the first production light to test for the MTBR bike lights shootout.

Edit: I'm no longer planning on producing these...not enough time...

Krit-
I've seen it while someone else is riding the bike around and it looked like a freight train was circling the neighborhood. I don't think that it is safe to ride on the road with it on high, it'll blind oncoming drivers!

[ifor powell]

Very interesting this. I just got some red led's to try out in my homemade headlight setup. Iinitaly I am just looking to experiment with them I was looking to try just one in my 6 led setup to see what differance it makes.

How well have you got the two stings matched? I can see that with some carefull measurment you should be able to get the two strings fairly evenly matched for a given current and thus get the curent shared evenly for that setting but with the two diferent types of led I wonder if things will stay matched at both the high level and the low level. Manufactureing somthing like this in a small scale seems like it would be fairly labour intensive to get things matched.

I would realy like to try the polymer optics if I could find a source for just small numbers. You realy are showing what can potentialy be done with them with the tight packing that is possible with them. 13 leds in a 2.5 inch diameter is amazing.

Ifor

[StevelKnievel]

I didn't spend much time with balancing the strings on this light. If you go by the vf from Cree's data sheets the string of 6 XR-Es has a vf of 19.8v @ 350mA and the string of 4 XR-Es and 3 XRs has a vf of 19.95v. I'm sure the variability in vf among the individual emitters could skew the balance some, so I'm building another light to see if I just got lucky on this one.

This light was an experiment, and I anticipated some strange behavior because the two types of emitters have different electrical characteristics depending on temperature, drive current, etc. Surprisingly the light has very consistent color and beam characteristics at both low and high levels and at low and high temps. Eventually I'll be using a dual-channel driver to drive the two strings equally and independently, for now this is working well as a test bed for thermals, optics, and color rendering.

I was exhausted after the ride last night and forgot to take beamshots. I'm not riding tonight so I'll take some and post them hot off the camera!

[StevelKnievel]

Finally some beamshots! This is with 10 XR-E Q4s and 3 XR Amber emitters.
(All shots F2.8, 2sec, Canon A620, Daylight White Balance)

Here is the big light running approx 600mA (~25w) with 9 25deg optics and 4 6deg optics:


This shot is the big light running approx 250mA (~10w)


for comparison, here is my personal triple Cree R2-WH, Cutter 14deg optic helmet light running at 900mA (~10w):


I am pleased with the output of the big light to say the least! The earth-tone colors are rendered clearly and it puts out a wall of light yet still manages to throw pretty well. The 13 individual optics allow the beam to be fine tuned from flood to spot by running different combinations. This combination is the best balance I found to suit my preference for a bar mounted light (lots of flood with minimal hotspot). I can only imagine how this thing would throw with 13 6deg optics, I'll put them in this weekend and find a good spot to go take long range beamshots. Cheers!

[Chriss]

Hello! I have a similar "big" bike light design which was started in 2005, just i still didnt fullfill the optics with LEDs since i have 16 place and i always looking for the better LEDs and driver:-) But i just received my maxflex2 and i will finish my light very soon.
Here are some pics about the original setup with cree XL3: (now i use SSC P4 LEDs)

[ifor powell]

Hello! I have a similar "big" bike light design which was started in 2005, just i still didnt fullfill the optics with LEDs since i have 16 place and i always looking for the better LEDs and driver:-) But i just received my maxflex2 and i will finish my light very soon.

Now that will be somthing to see Chriss if you fuly populate that... Are they also Polymer Optics?

Ifor

[ovlovder]

I have a project that has been on hold using the same optic, this make me want to get on it....

[Chriss]

Now that will be somthing to see Chriss if you fuly populate that... Are they also Polymer Optics?

Ifor

Yes Polymer Optics, 2x7 cell optics 6° and 2x 6° collimator.
Im planing to use 12 SSC P4 max 600ma/LED since this is the maximum what the Maxflex can drive from 12V.

[zcream]

Let me know too if this goes into production.. Not a bike light but I hope to mount it on my camera and use it as a camera light..

[RGB_LED]

StevelKnievel, that's a great looking light! I'm really surprised that those red LED's add to the depth of perception. Do you off-road with that light? If so, how do you find the weight on your helmet?

How much are you looking to sell the first batch at? Also what's the count on the first batch run? Man seriously, www.MEC.ca needs to get in touch with some of you builders out there. Perhaps some higher volume buys can lower the overall cost.

I doubt that MEC would be so proactive about carrying the latest lights considering some of the low-grade lights they carry now. They aren't bad lights, I just don't think we should expect them to be at the cutting edge. For example, a year ago, I overheard a conversation between a salesperson and a customer about the latest mini-m@glight LED drop-in and they were going on about how 'it's so bright and lasts forever'. I had to bite my tongue...

I've even e-mailed MEC a few times letting them know about LED technology and making suggestions about lights they should carry - i.e. I sent them a note last year about carrying the PT Apex and they said they would look into it. They also politely told me that they are all for keeping up-to-date with LED technology but it had to make sense from a sales perspective, etc. I know they have to perform due diligence but I had the light for a year and it took them 6+ months after I sent them an e-mail before they added it to their inventory even though they carried other PT lights!

I wonder how they would react if I told them about Fenix or Zebralights or Olights or...

[StevelKnievel]

The beamshots are actually with amber emitters in the place of the red ones I used on the first version of the light. The white/amber combo is awesome off road! Much better depth perception, color & detail rendering, etc. Pure white LEDs pale (literally) in comparison IMHO.

I designed this specifically as a handlebar light. The head is light enough (250g) that you could run it helmet mounted i guess, but it's pretty big and it would snag branches and vines on the trails I ride. I ride with the big one on the bars and a MR-11 sized triple Cree light mounted low towards the front of my helmet (last beamshot) to avoid the low-hanging Florida foliage.

[TomBrown]

Steve,

I haven't commented in any of the mega-light threads because they seem so far beyond my needs, I just enjoy reading the threads about these astounding devices.

I've been following this light for a while and am blown away by your idea to broaden the frequency range of the light with amber emitters. What a great idea.

I applaud the way you've gone beyond the size one-up-man-ship and have improved the quality of the light emitting from the front of the device.

Kudos to you and thank you for the inspiration.


Tom

[SemiMan]

I have a bit of an alternate approach to quality of light. I considered adding Amber emitters, but when I did my analysis, I found that when my light was running flat out, the heat and drive current would tremendously reduce the efficiency of the ambers. Instead, my light consists of 3 Cool-White and 3 Neutral-White emitters. The results is a very pleasing light that seems to pick up natural colors well. On low (about 150 lumens) next to my Fenix L2DCE it looks quite warm. Of course it cranks up to about 1,000 lumens at the top end as well though I rarely run it over 500. I use it on-road. There is a level of "respect" from motorists when you have something that bright. Likely they think I am a motorcycle.

Semiman

[nleahcim]

Are those Polymer Optics lenses? Where do you buy those? Any idea where to buy them in the USA? Is there anything better for the purpose?

[jbassett]

Edit: I'm no longer planning on producing these...not enough time...

It's a shame you're not going to supply them. Any chance of a CAD file for the housing to allow home production?

[StevelKnievel]

This style housing is probably more effort than it's worth. A triple MC-E or P7 light will be smaller, brighter, easier to design and cheaper to machine. Sadly, I don't have a CAD or CAM file to share. I machined it manually and didn't develop it in a CAD program.

The design is pretty basic though, there is an internal bore almost the full depth of the housing that is just large enough to fit the maxFlex driver and a switch. The LEDs are mounted on an aluminum MCPCB that seats in a larger bore deep enough to accommodate the optics and sealing elements. There is an internal snap-ring groove machined to allow the fitment of the spiral retaining ring at the front of the light. The fins/grooves were done with a 3/32" grooving tool and the groove depth increases toward the back of the light to allow good heat distribution with minimal mass.

[jbassett]

Thanks, very useful information

[John_Galt]

Wow, the depth perception with those amber LED's is amazing. Wonderfull build.

[jbassett]

Steve,
What battery pack do you run this from?

[StevelKnievel]

I've been using a 13.2V 4Ah NiMH waterbottle pack left over from a NiteRider HID lamp. The pack is getting pretty old and I'll probably go with a 14.8V Lithium pack when it dies.