Luxeon Tail light. Any input?

[Oznog]

I wonder if i can sand those optics out, for a smooth surface. That way i can just use the superfluxes plain or with some form of optic with no ill funky effects. Seems like it is maybe polycarbonate. i guess if i use a course followed with a set of fine-superfine wet sanding, i should be able to get it (used to paint model cars back in the day.) My other option is that i could use a clear coat and do a few layers untill smooth. i know the latter isnt better then the first, but would greatly reduce the effects.

I don't see any reason to want to sand out the optics. You want those optics! Those will help you for any LED arrangement. They will still help distribute the light, otherwise you might be blinded by looking straight at the tiny, intense emitter itself.

 

[justDIY]

check out the mods this dude did to his bike's rear lighting

**broken link removed**

Luxeons Galore

 

[Hero999]

Ignoring the law is fine providing you don't get caught. I suppose the biggest risk you take is your insurance becoming invalid if you have an accident in the dark, but you'll only get caught if your design fails or dazzles someone causing them to crash.

 

[Oznog]

I did the same thing with Arctic Silver adhesive. I gotta say that guaranteeing that the slug of the emitter (or the back of the Star) does not make electrical contact with the heatsink is a touchy proposition at best. I had to do several attempts where the multimeter showed contact before it was cured. And really with no pressure on the package (which would likely create an electrical connection) the thermal connection is poorer. Perhaps significantly poorer.

Not necessarily a killer problem, but just be aware it's an imperfect and touchy process.

I got a kick out of that guy's copper pipe arrangement. Copper is a better thermal conductor than even aluminum, but those mounting tabs are very thin. It seems doubtful though that he got an appropriate degree of flatness. Best thing is to get a cheap but very effective CPU heatsink and mount on that.

Actually now that I think about it, I wouldn't discount the Lamina devices (BL2000 is the one on my mind). I guess the lens WOULD have the ability to spread the light properly. I mean if you place the emitter where the original filament sat, obviously it can spread the light out ok. The original filament was a pretty small area to begin with. I may have been wrong on that point.

 

[hizzo3]

Holy bejesus, i thought that 4 lux 1's may be much, but damn. that guy could be mistaken for his tail end on fire. i guess there is only one way to find out... I'll order some luxes tomarrow. I love trying new things (prays that things dont turn to smoke and burn) lol

 

[Oznog]

Oh wait. I see the guy didn't bend the copper pipe out to put the emitters on, he used steel angle brackets!?!

Terrible. For one, steel has a relatively low thermal conductivity. It's not an effective heat sink material. Second, the screws holding a flat bracket to a copper pipe don't have the surface area of the contact area. It's an ineffective heat sink and will probably let the emitters overheat at even a fraction of their rating.

 

[hizzo3]

Oh wait. I see the guy didn't bend the copper pipe out to put the emitters on, he used steel angle brackets!?!

Terrible. For one, steel has a relatively low thermal conductivity. It's not an effective heat sink material. Second, the screws holding a flat bracket to a copper pipe don't have the surface area of the contact area. It's an ineffective heat sink and will probably let the emitters overheat at even a fraction of their rating.

to my understanding, luxeons dont put out that much heat. My inova t3 get barely warm after running for almost 10 mins, and its got a huge surface area. also i think the copper would move enough heat into the rest of it. i still would have never used copper pipe like that in the first place. guess thats all he had. something's better then nothing.

anyway, my question is now whats up with the lux 3's. If i read right, he was using 4 per lense. 3x4=12 luxeon 3's humm, even if he is running them at 50% that is 70 lumens each. 70x12=840 lumens of red light braking . Keep in mind a halogen headlight puts out 900-1100 lumens of white light. i wonder if he is attempting to use it as a heat lamp?

i'ma stick to my lux 1's and see how they go. if i need to go brighter (dont see why i would need to.) i can put in lux 3's and some major PWM to tame them.

btw, just saw this http://www.superbrightleds.com/specs/115x-xLX3.htm now i question the amperage of these. shouldn't it be almost 1 amp? even in regulation, 125 ma * 12 v = 1.5 watts. considering this is a 3 watt unit, how can it still put out the same light at 1.5 watts vs at 3 watts. I love misleading advertising. I love some of the other drop in's on the site. good for a few laughs.

 

[Oznog]

to my understanding, luxeons dont put out that much heat.

That's relative to what constitutes "much" heat. Light power is still only a small fraction of its power, most of it's heat so just guesstimate 1W. Remember how hot a 1W resistor can get?
But look further into the Luxeon spec sheet. A resistor can be allowed to get to an extremely high temp before it burns out. And running at high temp has little effect on its resistance. A Luxeon, however, is damaged by far lower temps and note that when under full power the emitter is considerably hotter than the heatsink. Also look at the efficiency vs temp graph, power output goes down a lot if it's not kept very cool.

From my experience, I know I don't have any measurements or calculations, but that guy's mounts are obviously inadequate for even a 1W device at full or maybe even half power.

btw, just saw this http://www.superbrightleds.com/specs/115x-xLX3.htm now i question the amperage of these. shouldn't it be almost 1 amp? even in regulation, 125 ma * 12 v = 1.5 watts. considering this is a 3 watt unit, how can it still put out the same light at 1.5 watts vs at 3 watts. I love misleading advertising. I love some of the other drop in's on the site. good for a few laughs.

Because they're lying. They used a 3W device and but don't have anywhere near enough heatsinking for 3W. So they're running it at 1/3rd power. They do this all the time. I think they used the 3W because it has superior ratings even at 1W but I'm not sure. Probably the same for your Inova light.

The SuperFlux are good because they just don't have the heat density issues and thermal mouting issues. I still say a bunch (10-20) of them will do a swell job.

 

[hizzo3]

well i know for a fact my inova is running just a tad above 3 watts. i think 3.2 hits it exactly IIRC. Plus i wouldnt need to plug it into an ammeter to find out anyway. it outshines my mag 2d with ease. doesnt throw as far, but at about 100-150 feet its more throw then i will ever need lol. well see how the lux 1's pan out first. cheaper anyway @ $2 a pop, vs the $.70 a peice for the superfluxes.

Oh how can they claim it is putting out 140 lumens then if they know its under driven, isnt that false advertising?

 

[justDIY]

Oh how can they claim it is putting out 140 lumens then if they know its under driven, isnt that false advertising?

despite popular belief, in the US, there are no laws actually against false advertising.

 

[hizzo3]

hummm... anyone up for some money making then? they are listed as automotive bulbs, and nowhere do they say for offroad use only. anyone wanna stage an accident and get some cash? LOL j/k. sad to think that is how things are done in our country....opps we lost a life whole well.....opps they sued and won, now lets change something, but make it cheap....