MC Headlight attempt question.

[Hypersapien]

Hi everyone,

Wow am I glad I happened upon this forum! I've spent the last few hours doubling my knowledge of all things LED and Lighting in general just by perusing these threads.

So I have a dual sport motorcycle that sees primarily street riding in town but also lots of off road riding and plenty of night riding on dark twisty roads. For the longest time I've been on the verge of ordering an OEM HID projector light out of an Acura TSX and custom moulding it into a new front fairing. Although I'm sure this could work (well) as I've seen it done before, I am now toying with the idea of an all led headlight setup or else an led high beam along with my current (tiny, deathwish, terrible...) dual 35W setup which uses ungodly small reflectors (about 1.75 in. dia. each).

Now looking at some of the attempts at an MC light on these forums I had an idea.

My proposal is this: To use some of the Cree mfg. supplied optics and a small array (maybe 7...?) high powered led's and create a functional off-road headlight using only off-the-shelf components.... OR and here's the idea I had (help me with this) create, in effect, a series of mini projector lenses using the supplied optics (various beam patterns) and a home-made cut-off shield for each inserted between the led face and the optic lens...

......Would this even be possible considering the way the optics and leds are assembled?

Would it even do what I'm thinking it might? That is, replicate a projector's means of operation?

What could be done in terms of simplistic coverings/shrouds to do what I want? Not blind drivers...(give the appearance of legality)

It is a bad idea on a few levels I gather... but I literally feel unsafe driving faster than 35 mph in pitch blackness.

Let me hear your thoughts on this as I am about to pull the trigger on this HID setup otherwise. And any of you who has some of these leds & optics laying around to tinker with any shots you could post up would be a huge help in making up my mind.

 

[bshanahan14rulz]

Somebody on here did LED high beams in a motorcycle housing. Why not keep the TSX (or go with TL if you have the money) and use LED for high beams? You would need a good combo of tight and wide focus optics.

 

[Hypersapien]

Yeah I thought about doing a combo projector/led setup too... The main reason I want to go all LED is because of a tiny space requirement and I would also like to keep it as light and compact and waterproof as I can.

I dont have any projectors yet to monkey with but I chose the TSX because of the OEM quality and the fact that its pretty much the smallest car projector out there at about 5.3 inches long (some links to very small projectors could easily swing me...)

I have done a few led builds in the past couple years (brake light, fog (position) lights... key fob) but I havn't tried anything that required a certain beam or very high output. All i have ever done is simple series branches with in line resistance running off of the vehicle's power.

Am I way off base in thinking that the optics behave like mini projectors so that I could just use a hand made cutoff?? It seems to me that the beam pattern is my only obstacle here... other than that I think its just a matter of the right parts and some tinkering.

 

[spencer]

I'm thinking of doing an offroad light setup using the XR-E LED some +/- 2.5 degree optics and some +/-5x25 degree optics, both from Polymer Optics.

The XP-G is due out sometime in the third quarter and has much better efficiency than the XP-E or XR-E. IMO worth the wait but you might not be wanting to wait. I will wait probably.

If you don't want to wait then I would go with the above option.

 

[LukeA]

I put this together. It's 10 LEDs, but it does use Cree-brand optics and the cutoff is really that simple, and could certainly be made out of a more durable material.

More info about the light here.

None of it will be legal though.

 

[bshanahan14rulz]

Dangit, Luke, I been looking for a project like that!

 

[Hypersapien]

Hey LukeA, nice build there!

I have access to a machine shop at school so the mount would be no problem.

My question earlier was not about shielding the light from outside the optics but from within them.. Is there any space between the led and the optic to put a thin shield or perhaps paint one on...?

How hot does the face of the optic get? And how much heat sinking do you think would be necessary for a build similar to yours?

 

[LukeA]

Hey LukeA, nice build there!

I have access to a machine shop at school so the mount would be no problem.

My question earlier was not about shielding the light from outside the optics but from within them.. Is there any space between the led and the optic to put a thin shield or perhaps paint one on...?

How hot does the face of the optic get? And how much heat sinking do you think would be necessary for a build similar to yours?

Thanks to you both for the compliments!

Yes, there's space to do that. You can pop the optics out of their holders and apply some paint to the refractive surface of the optic. You can't really install some mechanical shield in there because you need to have direct contact over the surface of the optic to stop it refracting. I've never tried it so I don't know how it will work with regard to the cutoff. That's one reason I went with the outside-the-optic approach, the further outside the optic the cutoff was, the sharper it was, so I assumed that the cutoff wouldn't get sharper when it was inside the optic.

The face of the optic doesn't get very hot at all, but your hand does feel warm when you put it in front of the light, but that's because of all the visible light being absorbed by your skin.

When I built the light, I intended to attach a finned heatsink to the back (hence the slots in the plate for the wires). I think you'd be golden if you attached a fin heatsink large enough in area to cover all the holes with 6 or eight screws and thermal compound or Fujik and ducted air over the fins. One and a half big CPU heatsinks like this with the backs milled flat would be excellent.

That said, if you're running the light for only short periods of time you may not need fins. I ran mine for 5 minutes continuously and the temperature of the plate went up 2˚C. So if the duty cycle is 40 minutes on, 1 hour or more off, you'd probably be fine.

The fins look cool though.

 

[Hypersapien]

Hmmm interesting about the heat on your setup there Luke. I didn't quite gather... are you running the strings on only 6 volts?

What is the amperage through any one led on yours?

 

[LukeA]

Hmmm interesting about the heat on your setup there Luke. I didn't quite gather... are you running the strings on only 6 volts?

What is the amperage through any one led on yours?

The unit runs on anywhere from 4-18V in. The current through each LED is IIRC 850mA or so.

 

[cleonard]

I've been playing with lighting for off road motorcycling for a while. I'm just getting into using LED's.

First you still need a good DOT legal low beam if you are going to ride on the road at night. I consider this a iron clad rule. It will be basically impossible to get the correct beam pattern with an LED using any kind of off the shelf optics.

For off road use I'll be building LED helmet lights. I currently have 150 watts of halogen lighting on high beam. Works OK out in the desert, but it can be a problem on the trails. On tight singletrack the light can point off into space at times, and that doesn't help at all. A helmet light points where you are looking.

A great site to look at is the DIY lighting forum over at mtbr.com They have many threads on helmet lights including tons of night beam shots so you can get an idea of how they work.

Another critical item is to have more than one light source. Nothing sucks more than sudden blackness when a lighting system fails for whatever reason. Guess how I know.

 

[Hypersapien]

Trouble is my headlight now isn't DOT and it was made for the bike... it is terrible I cannot stress this enough.

For the build to be a success all I would really need to do is tape a mag-light to the front fender and call it a masterpiece. I obviously need something better.

Could I use strictly "flare" style optics for a low beam and point them down enough to get the glare out of the drivers' eyes and then put a couple spot optics and a couple flood optics in combo with the flares for a high beam?

So Luke, what then do the drivers do? Since you run on 4-18 V don't you also need some type of voltage regulator or do they just get brighter with higher voltage? Thanks for the input guys.

 

[LukeA]

The DOT requirements are pretty specific and you won't be legal without meeting them. You may have to suffer with a stock low beam and an LED high beam.

The drivers regulate the current to each LED so the brightness is the same from 4-18V. The current requirement is inversely proportional to the voltage requirement.

 

[bshanahan14rulz]

Hypersapien, did you ever buy that TSX projector?

 

[Hypersapien]

Nope, I want to try the LED's out pretty bad. Just haven't decided quite yet as to which ones I should order. Along with the drivers and some more epoxy resin for the new fairing I will be making for this all to sit in.

Any suggestions on an initial assortment of supplies to play around with?