# Best optic/reflector for Cree XR-E?



## bikeny (Feb 26, 2004)

I am in the process of designing a triple Cree handlebar light. I think I have everything worked out as far as housing, driver (bflex) and battery, but I am trying to find the right optics. I have access to a machine shop, so before I get everything machined, I want to decide on the optics. I already have the LEDs, and got them with the Cree optics, which I think are like 8 degrees. Anyway, they seem like too much of a spot and I would like something with wider, probably around 15 to 20 dgrees. The LEDs will each have their own reflector. My only requirements are that they be round and no greater than about 30mm in diameter. So what is everyone using? Any suggestions would be greatly appreciated.

Mark

PS: This will be used for technical MTBing, thus the wider beam.


----------



## chrism (Jan 27, 2004)

I'm very happy with the output with the stock 8 degree Cree optic I'm using in my triple Cree light - seems a very good mix of flood and spot to me.










You'll note the light is quite yellow in that picture - not the fault of the LEDs, but because I don't have any white walls in my house :smilewinkgrin: . Light is at ~2.5m from the wall - I have to go that far back to merge the beams as it's a triple - and all the illumination you can see is from the light - the picture is quite close to what I actually see (full auto, but spot metered outside the main beam). As you can see there is quite a spot, but still plenty of light outside that.

Having been out with it on the MTB, there is plenty of close in spill to see both sides of the trail, though most of the light does go forward - actually seems to light up the trail quite well, and you can see most of the twists and turns. A separate helmet light is still pretty useful for seeing round the corners, but then I don't think any main light however floody is going to reduce the need for that, as you simply won't get the throw over a wide enough angle (I have a Exposure Lights joystick which is totally dwarfed by the main beam, but useful for this - is a very tight spot to get the throw though).

Hope to do some proper outside beam shots soon, which may help more.


----------



## robbbby (Oct 1, 2006)

So the beam in your photo has no secondary optic on it? Just the oem that comes supplied on every cree?


----------



## Low_Rider (Jan 15, 2004)

I haven't had enough time to play with many optics or reflectors yet to give you solid advice, but here are a few manufacturers that I have been playing with or have come across:

*Carclo Optics*

*Fraen*

*Khatod*

*L2 Optics*

*Ledil*

*Polymer Optics*

I haven't tried any reflectors at all yet, but the only reflectors I would bother trying with the Cree would be the "McR-**-XR" range which are made by Don McLeish. The datasheets are available *here*, and they can be purchased *here*. 



bikeny said:


> I am in the process of designing a triple Cree handlebar light.


Out of interest, are you planning on a cluster style arrangement, or a flat row of emitters?



robbbby said:


> So the beam in your photo has no secondary optic on it? Just the OEM that comes supplied on every Cree?


Cree have their own secondary optics for some of their emitters, including the XR-E. These are separate optics, and are not the "dome" which is permanently attached to the emitter. There are datasheets available on their website. :thumbsup:

Cheers, Dave.


----------



## achesalot (Nov 8, 2005)

I think Dave covered most of the optics that are available. There are a couple of reflectors that I can think of, but they give more throw than flood, so stick with optics.

I used the Ledil optics 1x4 and 2x9 in my Triple Cree helmet light. I've ordered two 15 degree lenses for my handlebar light. I've had good success with these, but they are square, not round. I would try the Carlco 15 degree (10201) . I've never used them, but heard good things here and elsewhere.


----------



## Low_Rider (Jan 15, 2004)

My favourite optics for the Luxeon emitters were the narrow (10003) and medium (10003/15) Carclo optics. A triple emitter cluster with the narrow optics made a great bright and wide spot with a nice side spill (flood), which made a great primary light. The medium optics provided a huge wall of light with only a barely noticeable spot, which was great as a handlebar mounted light to provide a huge flood to compliment a helmet mounted light. I tried many different optics with the Luxeons, but I always came back to the Carclo stuff, they certainly appeared to be superior to other manufacturer’s products in my setup.

I would be interested to see how the Carclo Optics would behave with the Cree XR-E. I’ll have to have a play.


----------



## bikeny (Feb 26, 2004)

*Thanks for all of the replies!*

Thanks everyone for the good information. I checked out the reflectors, and as Achesalot said, they seem designed mostly for flashlights and a long throw, so those are out. I think I may try out those Carclo optics, probably order the 15 deg. ones. I just noticed that Cutter now has them on their web site. I just got my order from Cutter last week, and those optics were not there, otherwise I would have ordered some, oh well!

I was originally hoping to find something closer to 30mm in diameter, my thinking was the larger diameter they are, the more efficient they would be. But I cannot seem to find anything that size with the proper beam angle. Most of them are either tight spots (like 4 deg.) or floods (like 25-30 deg.).

So, it looks like I will wait for the Q2 bins to be available from Cutter, hopefully soon, and then order some Carclo optics and Q2 Crees.

Also, someone asked what kind of configuration I was putting the LEDs in. My design will put the 3 LEDs in an arc that will mount on both sides of the stem clamp on the bar. Maybe I will try to get a drawing posted for you guys to see.

I am also in the final stages of making a single Cree helmet like running from a 1000ma buckpuck with a 35mm single optic, lots of heatsinking, and a 3 position switch for off-low-high.

Mark


----------



## GMF (Jan 10, 2004)

I've played around with several optics for the cree, and the one i am happiest with is the MCR-19 reflector by Don McLeish. It is not a cree specific reflector, but it certainly gives a nice beam pattern. Hopefully, i am going to try more of his reflectors, but this one gives a nice center hot spot with a moderate side spill. The MCR-27-XR gives a little more flood, which you might be interested in.

They are pricey, but they give a much cleaner beam pattern than many of the plastic optics i tried.

Good luck,
-Damon


----------



## bikeny (Feb 26, 2004)

*Here is a preliminary picture:*

Here is a preliminary picture from my CAD file. It is not finished yet and some details still need to be woked out, but it will give you a good idea. Any comments/suggestions are welcome:


----------



## GMF (Jan 10, 2004)

bikeny said:


> Here is a preliminary picture from my CAD file. It is not finished yet and some details still need to be woked out, but it will give you a good idea. Any comments/suggestions are welcome:


Looks cool, but it seems bigger than it needs to be, and you might have an over-constraint problem with your two clamps, but realistically i bet it'll work just fine. Is your only adjustability up/down?

Do you have access to a CNC mill? Doing that by hand would require more skill than most people have. You might also want to put the parting line close to the front so you only have to bore out one side, and lens retention becomes a bit more straight forward. Throw in some o-rings while you are at it to make it waterproof.

-Damon


----------



## bikeny (Feb 26, 2004)

Thanks for the comments. I will try to answer your questions/concerns:



GMF said:


> Looks cool, but it seems bigger than it needs to be


You are correct, it is a little big right now. It was originally designed for optics around 30mm and a buckpuck and 2 switches, therefore the size. I just recently decided to use the bflex driver, so that means I can reduce the size. Also, if I end up using 20mm optics, the diameter of each 'pod' can be reduced.



GMF said:


> and you might have an over-constraint problem with your two clamps, but realistically i bet it'll work just fine. Is your only adjustability up/down?


The 2 clamps are probably overkill, but I really liked the idea of the light being centered on the bar. The clamps have rubber inserts that can flex and they each mount with a single screw so they can rotate, and yes, the only adjustability will be up/down. I have never seen a need to have lights adjustable left/right unless they are mounted at a funny angle on a riser or something, which this will not.



GMF said:


> Do you have access to a CNC mill? Doing that by hand would require more skill than most people have.


YES! This will be done on a CNC, not by hand.



GMF said:


> You might also want to put the parting line close to the front so you only have to bore out one side, and lens retention becomes a bit more straight forward. Throw in some o-rings while you are at it to make it waterproof.


The parting line was put in the middle on purpose. Only the front half needs to be bored out, as the reflectors end just at the parting line. There are 3 slightly raised sections on the back half that the LEDs will mount to that will align with the bores to keep everything in line. I have not decided about sealing yet, may still be incorporated.


----------



## chrism (Jan 27, 2004)

bikeny said:


> The parting line was put in the middle on purpose. Only the front half needs to be bored out, as the reflectors end just at the parting line. There are 3 slightly raised sections on the back half that the LEDs will mount to that will align with the bores to keep everything in line. I have not decided about sealing yet, may still be incorporated.


In which case there seems an awful lot of material in the back - it's not like you need a lot of room for a bFlex.


----------



## bikeny (Feb 26, 2004)

chrism said:


> In which case there seems an awful lot of material in the back - it's not like you need a lot of room for a bFlex.


Yes, you are right. As I said before, it was originally designed for a Buckpuck, and therefore I needed the thickness. Besides, it acts as a nice big heatsink!:thumbsup:

Mark


----------



## chrism (Jan 27, 2004)

bikeny said:


> Besides, it acts as a nice big heatsink!:thumbsup:
> 
> Mark


Though you have to understand that the purpose of a heatsink is to get the heat into the air, and extra mass doesn't help at all with this (it will take longer to heat up, but in steady state it will still be at the same temperature). To transfer heat to the air you need surface area, so you really want to machine some fins or at least some grooves into all that metal back there to increase that.


----------



## Tinier (Apr 13, 2006)

Bikeny, that is a very nice design. Are you making just one, because if you are going to make more than one, I might be interested.


----------



## p97z (Dec 19, 2006)

Looks like something I would be interested in also... I like it!


----------



## achesalot (Nov 8, 2005)

Looks cool. Got a CNC lathe?


----------



## bikeny (Feb 26, 2004)

Thanks for the replies and compliments on the housing. I do not have access to a CNC lathe, but I can do some simple stuff myself. If and when I finally go through with this, I will probably have a couple of them made. If there is some interest I would think about selling some of the housings. Keep in mind that they will all be exactly the same, and there would be no options, and it would be just the housing, no LEDs, optics, drivers, or batteries. I still have not decided on the optics for the LEDs yet and am still open to suggestions. I will have mounting for a bFlex driver. I am also not sure about where to put the switch yet. I am thinking about trying the find a switch that will come straight out the back of the housing, and then have the cable come out the bottom. 

Mark


----------



## JohnnyM (Jan 9, 2007)

GMF said:


> I've played around with several optics for the cree, and the one i am happiest with is the MCR-19 reflector by Don McLeish. It is not a cree specific reflector, but it certainly gives a nice beam pattern. Hopefully, i am going to try more of his reflectors, but this one gives a nice center hot spot with a moderate side spill. The MCR-27-XR gives a little more flood, which you might be interested in.
> 
> They are pricey, but they give a much cleaner beam pattern than many of the plastic optics i tried.
> 
> ...


Hi Damon,
any chance of seeing a beam pattern from one of these. Brightness doesn't matter - I just need to know the distance between the light and the target (wall or whatever). With that, I can have a stab at working out the beam angle.
Cheers,
JM


----------



## GMF (Jan 10, 2004)

JohnnyM said:


> Hi Damon,
> any chance of seeing a beam pattern from one of these. ...With that, I can have a stab at working out the beam angle.


I'll make it easy for you... the hash marks on the wall (going up from center) are in 1 inch increments. The light is 1 meter away (sorry for the mixed units). I count about 12 inches radial with my higher resolution shot on my computer here (the first one is pretty washed out). Interesting thing is that having the LED off center seems to eliminate the ring, not that you can notice it on the road...

-Damon


----------

