SureFire L4 Luxeon K2 TFFC SOB1250 Mod

[darkzero]

Here's a mod that I did for someone on another forum, not sure if he's here on CPF too. Nothing out of the ordinary but I don't think this has been done before as everyone goes with the quad die setup in KL4s. I've done plenty of P7 & MC-E KL4s but this one is probably my favorite.

Owner wanted more throw so I bored out the head to accept a McR-20. Made a tighter fitting beefier heatsink. Driver potted for extra protection. Hope the owner enjoys!

-SureFire L4
-Luxeon K2 TFFC UWOE
-SOB1250 (measured 1244ma)
-McR-20

[darkzero]

Beamshots taken at 15ft.

Left: SF L4 K2 TFFC mod, Right: Stock SF L4



Left: SF L4 K2 TFFC mod, Right: PD-S U2SVOH 720ma (my EDC)



Left: SF L4 K2 TFFC mod, Right: HD45 XX1T NewBB (keep in mind this is a 45mm reflector with a X-bin LuxV)



Left: Left: SF L4 K2 TFFC mod, Right: Aleph3 WX1S DB1250

[mossyoak]

any idea as to the OTF lumens and what type of runtime the lucky new owner will get?
i bet the beamshot of this light is beautiful, it should be just like a mcg with a lux3 in it. just significantly brighter.

[darkzero]

any idea as to the OTF lumens and what type of runtime the lucky new owner will get?
i bet the beamshot of this light is beautiful, it should be just like a mcg with a lux3 in it. just significantly brighter.

No idea what the actual runtime is but one can calculate it. I believe the owber will be using lithium primaries with it. I'm working on posting beamshots now.

[mossyoak]

No idea what the actual runtime is but one can calculate it. I believe the owber will be using lithium primaries with it. I'm working on posting beamshots now.

very nice work as always DZ, ill sit tight waitin on those beamshots.

[darkzero]

very nice work as always DZ, ill sit tight waitin on those beamshots.

Thank you. Beamshots up.

[nanotech17]

fantastic.
i just love k2 tffc.

[DaFABRICATA]

Thats Sweeet!!

Will, I love your mods!...SOOOO CLEAN!!

I have yet to mess with the K2's, but seeing this and being able to use Blindasabat's L1 Head with a K2 has made me want to buy some...

Awesome Mod!

[tx101]

Wow, great mod

These K2 TFFCs produce an intense hotspot, perfect for all you throw-fans

[AaronM]

Where did you get (or how did mod) an SOB1250?
What epoxy are you using to stick the SOB to the brass plate and does it have decent thermal properties?

[tx101]

Where did you get (or how did mod) an SOB1250?

By changing the sense resistor.
Wayne (The Shoppe) will solder the resistors on for you.
Just order the board as a blank and select the resistors
You can work out which resistors you need by looking it up here

[darkzero]

Thanks guys!

Where did you get (or how did mod) an SOB1250?
What epoxy are you using to stick the SOB to the brass plate and does it have decent thermal properties?

To get a SOB1250 I use .10, .12, & .15 sense resistors. The SOB is not epoxied to the brass ring, it's soldered on from the bottom which makes the ground path.

The epoxy I am using there is just Devcon 2-ton epoxy mixed with alumina oxide powder. It the same mix I've always used for all my builds including for mounting emitters. The datasheet also states it can be used for potting electronics. The alumina oxide powder increases thermal conductivity but the reason I pot the electronics is for better impact resistance. I suspect the owner being in some type of law enforcement work so I wanted to make it as heavy duty as possible.

[TranquillityBase]

Perfection! Nuff said

[olrac]

Good to see shots on the lathe as well. great work that we have come to expect from DZ

[AaronM]

Wow thanks, learn something everyday.
So you stacked (ran in parallel) the .12 and .15 resistors to get .0675 ohms?

[Justin Case]

If you don't want to solder your own sense resistors, you can order a blank SOB, order the resistors from the menu, and have Wayne solder them for you. The combos on the menu won't get you to 1250mA output, but you can get close with an SOB1227 using .05 and .22 resistors.

[toby_pra]

Nothing more to say...

Awesome clean mod!

[darkzero]

Wow thanks, learn something everyday.
So you stacked (ran in parallel) the .12 and .15 resistors to get .0675 ohms?

Yes correct, stacked the third resistor. Doesn't matter which combo, you'll still end up with a total parallel resistence of .04. Years ago when I used to make DB1200 (1194) & DB1250 McLux heads this how it had to be done which was long before Wayne offered the .05 resistor or that I was even aware it was available. I still prefer using the 3 resistor solution to get a wider range of values.

Here's a pic showing stacked resistors (don't mind the stacked boards).

[AaronM]

OMG! An SOB3650?!? I want!
Seriously, I officially lost count of the cool new ideas I got from this one thread and the workmanship is inspiring.

[darkzero]

OMG! An SOB3650?!? I want!
Seriously, I officially lost count of the cool new ideas I got from this one thread and the workmanship is inspiring.

Nope, actually a GD3333 that I built back when there was no driver available for driving a P7 that high. The original post is here & it went into this.

[AaronM]

Still, I imagine a guy could make a double or triple stack of just about any like drivers and make it work in some application or other.
What gauge and type of wire do you use to pin them together?

[KDOG3]

Good grief I wish I could do that kind of thing. But my eyes are too bad and my hands are too shaky anymore. Well when I need someone to put a new XPG in my LX2 I know who to contact...

[brighterisbetter]

Looks amazing as always Will, nice job . I too am a big fan of the K2 TFFC

[Greg G]

Great thread on a great light.

I always like reading your mod threads. Never finished one without a smile on my face.

[AaronM]

I too had to try this mod...



It was a success, but talk about no wiggle room at all!
I think next time I'll push the driver farther down into the mounting ring before I solder them together.

[roguesw]

I see you potted the driver, what did you use to pot the driver?
Is it just regular epoxy ?
With such a small package, every little bit helps when considering heatsinking.

[darkzero]

I see you potted the driver, what did you use to pot the driver?
Is it just regular epoxy ?
With such a small package, every little bit helps when considering heatsinking.

Yes regular epoxy mixed with alumina oxide powder. I posted in post #12

I too had to try this mod....

Nice work Aaron!