This is what the cree spec says: Maximum drive current: up to 500 ma
Of course it's possible to drive them higher, but then the weak link also becomes the single bonding wire for the xp-c's. The flux curve also starts flattening out I would imagine above 1A no matter what the cooling since cree graph is done at the junction temperature which is independent of anything downstream.
I also have the DX lens and at least it fits in my hosts, though I don't use it enough to make it worth blacking out any reflectors.
I definitely want to see the lux numbers for a SkyRay with an XPC and DX Aspheric. I realize that there are various way to do the "pill" but I'd like to see something done that is possible by an average modder. (I'm thinking along the lines of dormpuller's triples here).
If you are looking for a great flooder why not skip the aspheric and just use diffusing film over the existing glass lens?
How does the aspheric do that? Wouldn't it be better just to remove the reflector and kept the front glass lens (with or without a diffuser)?
Just curious.
I know what the Cree spec sheet says. But you have to understand the context of how those numbers are arrived at. They have to have the LEDs not die in 10s of thousands of hours. I do not. They set the maximum based on what they see as a "normal" thermal path that the various industries will provide their LEDs. My solution is most definitely not the norm.
The flux curve "starts to flatten out" at any given current when compared to a lower current. Such is the nature of blue based white LEDs. It is up to the lighting designer to decide where their personal "sweet spot" is based on the various parameters involved with the light and the goals set out for the light. There is noone in this world who has more experience than me with overdriving LEDs. I know what the weak links are and how to design around them or stay within them.
Is this for use on a bike? Would the effect be better (or not for you) if diffusion film was used either in addition to the aspheric or without the aspheric but with a reflector? The hard outer edge that you have (the large circle) would not be there if diffusion film was used.
Does that not matter in your application?
I'd like to learn more about bike lighting applications (especially mountain biking) as it seems those applications are similar to ones I'm interested in (dive lighting). Both activities face some of the same obstacles...tough environment with a need for strong focused lighting (in some cases).
With hiking and headlamps I'm more interested in a little throw with more diffused lighting in general. I get extreme throw from a separate source. My experience with aspherics is primarily with throw. I am aware of flood-to-throw applications where the aspheric is thrown out of focus as in your case.
Thanks Be-Seen Triker. Interesting!
I just got 2984L OTF / 32k lux @ 1m (calculated, i measure at 8.17m) throw from my overdriven Sky Ray 3 x T6. hehe... Dry ice and some fan (to keep the reflectors from fogging up, the dew point and RH is always high here).
Actually the DX meter which i've got is known to under-read by 10-20% according to ma_sha1.
Yes, I know how semi's are designed, manufactured, and tested. I'm only pointing out what's apparent from the spec sheet. For instance, the max current is an instantaneous spec, not just a continuously driven one. That's why they have a separate graph for junction temp vs. efficacy.
Just as "overclocked" parts can work with increased gate speeds, I'm sure proof of your light's operation is empirical, though this is YMMV territory. However, it's also quite empirical that cree's graphs of efficacy vs. current are at fixed junction temp. If you have done or know of statistically significant measurements as current is increased, you can also show them.
Just a quick update to this thread: I believe saabluster may have changed his mind about wanting the light reviewed, as I haven't heard back from him.
I really can't blame the guy for not wanting to send a light to some stranger he doesn't know to be reviewed on a board he doesn't visit that's populated by folks who'd most likely never purchase his lights (Yay for run-on sentences!)
Not all is lost however. In preparation for the now cancelled review, I've ordered a few different small aspherics along with a couple of the new xp-e R4 bin emitters from cutter (and as always, plenty of copper). I've got a few ideas in mind now for a small thrower... 
It's always fun to see/hear about more aspheric throwers! I got around 6.500 lux from a small (18 mm aspheric) single 14500 light and that's only driven around 650 mA. I have another one about the size of the DEFT EDC that uses a 30 mm aspheric and is driven around 900 mA that is in the 25,000 lux range and a 1A driven 18650 with 38 mm aspheric at 45,000 lux.
I'm sure you can improve the heatsinking and current draw over what I've done. It will be interesting to see your work!
Hi all,
1st post here. I been measuring OTF lumens for 100's of lights now over at CPF with the help of MrGman, who lost his access to the lab late last year. (a real dedicated lab at Military vendor that builds LED cockpits for apache and other military Jets) So, a pretty sophisticated lab to say the least.
Here is my take:
I have incorporated the help of a buddy who builds custom copper slug heatsinks for me in order to drive the XR-E -R2 at 1.5A~2A. I tested both EZ900 and EZ100 for 1m lux (taken at 5m and math backwards) and OTF luemens.
With a Solarforce L2P hosts and a copper slug pill. The XR-E R2 EZ900 (DX purchased) at 1.4A, 1.6A, 1.8A, and 2A no matter what I did It would not go over 32.5K lux at 1m and 140 OTF lumens, so I settled at 1.8A.(5M lux and OTF lumen test both done with Ahorton 27.5mm lens)
Then
I got a XR-E R2 EZ100 (salvaged from Stock Surefire L1) I see lumens go up and up from 1.4A~1.8A. At 1.8A~2A it made no difference in OTF lumens. Again here I just get 1.8A due to Direct Drive off IMR 18650 cell. But to my surprise it too settles at 1.8A and I get 220ish OTF lumens and 27.5K lux. Yes; lux is less then the EZ900.
I decided to keep the EZ100 because side by side by eyes cant tell which throw more. What my eyes can definitely tell is how much more impressive the EZ100 is. It just puts out so much more light OTF that I decided to keep this one.
Still I need to fine tune it more. The LED can still be bonded direct to the copper heatsink, but I would have to get help there because that is an almost impossible task and to my knowledge only Saabluster, Milkyspits, and Lamdalights.com have done this succesfully.
To further contribute here. My goal has always been to prove the impossible possible and the just plain silly feasible.. Just look at Lamdalight.com website: Here he build 2 lights for me. With my crazy ideas and his LED to copper bonding.
http://flashlightnews.net/forum/index.php?topic=2595.0
http://flashlightnews.net/forum/index.php?topic=2619.0
The amount of time it takes to properly make a copper slug, design a thermal path, and then bond the LED direct to copper is incredibly difficult and you can already imagine all the machinary and expertise needed to do so. threaded copper slugs are hard on tools and not many shops do it.
I will be meeting up with 40 or more flashaholics here in bayarea,CA on October 1st. What I offer here and elsewhere is simple.
JUST IN: Another member has a DEFT EDC and will bring it to the meet.
I will take the hit and purchase the $199 DEFT EDC and do a side by side review against my 27.5mm Aspheric drop-in. Granted you can see my drop-in will be copper slug and at 1.8A the XR-E R2 is screaming hot within a minute, thus the huge copper heatsink.
Of course OTF lumens and 5M lux readings will be taken on the DEFT EDC, but we all know since throw is what we are after here that 40K lux will be hard to beat.
What can I do to get more lux since I am topped out at 32.5K at 1m (actually tested at 5m) Well several things. For one, I can use a real XR-E R2 EZ100 purchased directly from Cuttereclectronics. They cost $9 bucks which is alot for XR-E R2 IMHO. Maybe I can get a buddy to do a LED to copper bonding for me.
Here is a copper P60 pill my buddy builds, but for the get together He will thread the outside of the pill to thread into the hosts and it will use alot more copper.
Hey bigchelis, nice to see ya here!
Happy to be here...I also just confirmed my personal XR-E R2 EZ100 will be bumped up via 2.1A driver and more copper slug via Pelican M6 hosts instead. The same Ahorton 27.5mm Aspheric will be used.
The DEFT EDC will be at the meet and greet on Oct 1st for me to challenge it.
Also for those of you that are budget friendly. Here is the receipt for 27K lux at 1m (measured at 5M).
- Nailbender made or other home made XR-E R2 EZ100 with 1.4A driver.
- Get a grinding stone/sandpaper whatever and grind away about 50% off the reflector untill the Aspheric is at full tight focus.
- You need the Ahorton 27.5mm Aspheric because the focal lengh is .5in vs. DX/KD I have tried are about 1in focal lengh. Yes, this makes a huge difference in OTF lumens and lux.
- Paint the reflector black or leave it as is, youre choice.
This way I still got instant peak of 27K lux and 200~210 OTF lumens even with the Aspheric on. But as you can imagine I couldnt go higher in to more current untill I bumped up the heatsink and thermal path design, which is when I had my buddy do the copper slug heatsinks.
This may seem not worth it. Going with factory readily made parts you spend around $20 bucks and still get 27K lux and 200 OTF lumens. Why would I spend over $100 on custom work and gain only 500 lux??? Its the journey I guess and to test what can be done. Sometimes the rewards are great, while sometimes not so much.
bigC
Bigchelis, it might not work but have you tried pelleted dry ice just for kicks and knowledge?
It might fog up the Aspheric as the ice melts, or I think it will.
What my buddy said he will do now is make the XR-E R2 EZ100 bonded directly to copper slug heatsink. Its not easy to do, but he will make it happen via new method he is developing
bigC
It would fog up the aspheric if you hesitate too long. Also in a dry cold room (dehmidified) it would be pretty difficult to fog up anyway. I tried it on a DD triple XM-L. In relation to known lights i believe i drove it to about 3800L "OTF" and that's witht the lousy lens and reflector. I used a SLA at full charge plus charger to put some extra juice. The LEDs went out twice actually, but i hit it hard on the head and it came back on....not sure if the bond wires broke or something. LOL!
You know, it must be NICE to live in an area where there's very little street lighting. No wonder it can "throw". :)
Well its official.
I will have at leastt 1 DEFT EDC to test out on October 1st, possible 2 of them to pit against the 2.1A XR-E R2 EZ1000. By the way the DEFT EDC uses the same aspheric my XR-E R2 EZ1000 will use.
bigC