Surefire L2 with Cree MC-E

Surefire L2


L2 head disassembled



Original heatsink



New heatsink with MC-E (the driver is in the light-body)







Luxeon 5 (left) - Cree MC-E (right)
Luxeon 5: 110 emitter lumen at 700 mA, 6,8V
Cree MC-E: 370 emitter lumen at 700 mA 6,4 V (2S2P)





Distance to the Wall 3 yards
Pics underexposed

Surefire E1L Cree 2stage (on high)


Stock Surefire L2 (with Luxeon 5)


Modified Surefire L2 (with Cree MC-E)


Beamshots / Animation: Link


IR-Scan: see Post #49

Surefire L4 / KL4 mod: Link

Wow, great job!

I want one now. :thumbsup:

Sweet light! :thumbsup:

What driver are you using?

did you make that heatsink yourself?

mudman cj said:

What driver are you using?

Click to expand...

Stock driver (approx. 6,4 V, 700 mA) and the original battery-contacts in the head. Same runtime as before.
Only the heatsink is new (and the MC-E, of course).

@Illum the nation: yes, the heatsink is homemade.

Nice
You don't seem to have any artifacts from the reflector either,which is great.

Cheers
Dom

very nice mod...now I am thinking it is something to do with my L2...couple of questions?

Where did you get the LED

how did you get the head appart without damaging anything?

Are you willing to make another heatsink? I want one!

Thanks

Boltgun

I´ve got the MC-E here: Link
I make single pieces only, therefore no additional heatsinks. Sorry.

The L2 head came appart quite easy. I´ve used a heat gun and two strap wrenches.

Nice heatsink!

I've got an L2 that disparately needs an upgrade. I was thinking of sending it off to be modded, but this actually looks like a fairly simple procedure. I've got a little milling machine, no lathe though, so assuming I can find some aluminum bar stock of the appropriate diameter, I should be able to mill a heat sink out of it.

Please excuse my ignorance of LED emitters and electronics in general, but would I be able to use a P7 in place of the MC-E? Would that even be an advantage? The P7 is quite a bit larger in diameter, so I would have to open up the hole in the reflector.

Another question...

I've been told using rechargables in this light will destroy it. Is that due to the driver or emitter? Does this mod allow for the use of rechargables?

One more...

What is different between the old heat sink and the one you made? Just the seat for the emitter?

The stock L2 driver delivers 6-7 V at 700 mA.
Vf of the P7 is 3.4-3,6 V, which is to low.

The MC-E can be wired 2S2P. Then the voltage ist approx. 6,4 V, perfect with the stock driver.
Each die gets 3,2 V and 350 mA:




You can use a rechargeable cell: 3,7 V, 1.100 mAh (AW´s protected 14670)

You can use the stock heatsink. But you need a small copper piece under the MC-E, approx. 1,4 mm high.
I´ve made a new heatsink with a slightly smaller diameter (20 mm) than the stock heatsink. So I can adjust the emitter radial after glueing it to the heatsink.

Did you measure the current at the LED? I recall runtime graphs of the L2 showing a much steeper drop off in output compared to the KL4 (L4). I think current to the LED of the L2 is probably 880 or so, if my memory serves me. What does the MC-E pull from the batteries.

Just measured the battery current (with 2 fresh 3 V Surefire cells):
L2 #A27298 with luxeon 5: 1,01 A
L2 #A19282 with Cree MC-E: 1,10 A
KL4 #A39334 with Cree MC-E: 1,08 A

I think, you´re right. Current to the led is higher than 700 mA and probably between 800 - 900 mA.


Edit:
current to the led (L2 with MC-E) is 795 mA (with two fresh 3 V Surefire cells)

Beautiful job. I think of doing something similar to boost the output of my stock L2, but like its lower output for a number of purposes (close up work), and ended up just buying new brighter lights. Besides, my L2 was the first "real" light I bought that ultimately led me look at company's other models, and then to this forum...so it has a sentimental place in my heart.

Ok, I've got everything I need to get started on mine.

One question though.

I am going to use the stock heat sink and machine a riser. Is there any reason why I should not use the riser as the jumper connection and solder directly to it?

Also, I have some copper and some silver that I could use as the material for the riser, I know i can solder directly to copper, can I solder to silver in the same manner?

Thanks

This is a wonderful job!
One question: how's the donut? Is there an X-shaped null void at the center? I'm amazed it looks to do so well and so throwy with the stock reflector - if there's no donut, that's awesome!

Look forward to hearing from you =) Great work.

I've also done this mod and can report that if you keep the spacer height below 1.80mm
there will be no doughnut.

Take a peek at post #54 on this thread for details:

https://www.candlepowerforums.com/threads/210173&page=2

Well, here's my progress so far...

Here is the heat sink with original emitter removed.



The MC-E just barely squeezes down into place behind the reflector. This is perfect as this automatically centers the emitter in the reflector and holds it securely. This also gives me a couple of good spots where I can add epoxy and secure the emitter permanently after everything else is done.





New riser. Dimensions: .5x.25x.048"




The material used to make the riser, 1oz pure silver bullion investment slab.