Sofirn C8F host. 21700 C8F Available

[Nooner]

@djozz

@Nooner

Hi. Looking for input.

What would be an appropriate driver if this light was built with red xpe2 LEDs?

My newbie sense is telling me direct drive is a no go. I think I’ve got that much figured out. But can anyone recommend a driver that would use the xpe2(s) to the fullest?

Thank you in advance.

red XP-E2 to the fullest (which is perfect on this this big copper DTP board) would be about 2A each, so you need a regulated 6A driver. The only driver I can think of that will do that is a lineair driver with 16x 7135 chips, you can buy a 8x 7135 driver and stack an extra chip on top of all of them. This solder job is something you have to be in the mood for . Still, because the red leds have so low Vf, the 7135 chips have to burn off a lot of overvoltage so they get really hot, make sure that they have a good heat path to the pill (like clamp the driver wel on both sides, and use extra solder on the outside of the chips to create the heat path.

Thanks for the input djozz.
In researching this idea I’ve found some of your previous posts on red light builds.
So thanks for that info also.

I figured a standard 7135x8 would work. Didn’t realize 16 was an option.

Time to take some carts to the checkout!

[eas]

@HarleyQuin

Considering hosts: I‘d love to see the upcoming K6 (SRK style) as a host, meaning with reflector, LED-MCPCB and backplate, but without LEDs and driver. I do replace those anyway :smiling_imp:
The SF11 might make a nice host as well.

I’m drawn to the idea of the SP33 as a host. At least I think I am. The T-shaped driver assembly might made things more challening than I’d hope. On the other hand, it seems like the stock driver is direct drive with fast PWM — if only it had an AVR MCU to make custom firmware easier.

[JasonWW]

@eas

@HarleyQuin

Considering hosts: I‘d love to see the upcoming K6 (SRK style) as a host, meaning with reflector, LED-MCPCB and backplate, but without LEDs and driver. I do replace those anyway :smiling_imp:
The SF11 might make a nice host as well.

I’m drawn to the idea of the SP33 as a host. At least I think I am. The T-shaped driver assembly might made things more challening than I’d hope. On the other hand, it seems like the stock driver is direct drive with fast PWM — if only it had an AVR MCU to make custom firmware easier.

The SP33 looks like a tricky design to use as a host. I think the Supfire L5-S, like in my sig, has a definite advantage with its conventional 26mm driver. Especially when Lexel comes out with his boost driver. Then you could run a xhp 35, 50.2 or 70.2 with a single 26650 and have Narsil as well.

The SP33 has a nice looking side button and finish, but I wish it had a tail switch as well to act as a lock out.

[tekwyzrd]

Just today I received the c8f host I ordered from the sofirn aliexpress page. Very impressed by the quality. The fact that they offer paypal payment is a plus. Currently communicating with Lexel about a driver. My choice of nichia 219c may be lower output than some cree options but the 90+ cri will likely make it one of my favorites.

[Newlumen]

Mtnelectronics just got those host for $15.

http://www.mtnelectronics.com/index.php?route=product/product&product_id=939

[tekwyzrd]

@Newlumen

Mtnelectronics just got those host for $15.

http://www.mtnelectronics.com/index.php?route=product/product&product_id=939

Thanks for the info!

[Zappaman]

As I have suffered through a few of these C8F builds, here is some fast feedback for those cranking up their soldering stations:

1) take a drill bit (about a 3/16”) and carefully move the switch wires to the side while going in from the rear (driver side)— and ream out the wire holes from the back of the head’s heat sink. My first build was a frickin’ mess due to my 18g wires catching on the razor sharp edges left from Sofirn’s manufacturing of the host. I ALSO lightly reamed the FRONT edge of these wire holes too. I wasted my MCPCB on build #1 because the LED wires kept catching on these sharp edges, causing me to rip off one of the wires from the MCPCB trace completely— so making it unusable. I also pulled up the copper trace on the driver- but Lexel helped me with a second connect point (and… THANKS again Lexel!)

2) The tail cap bi-pass is pretty thin from the factory. I replaced mine as it came off (or shorted?) within the first few days of use. Good idea, but not well done at the factory (several others have had this failure too). So just replace it when building and be done with it!

3) Don’t forget the little plastic washer (used as a spacer) between the reflector and host’s front face— when you put that screw in— easy miss; and the face will not be square without it of course (how I figured it out— the hard way).

4) IF you use Lexel’s tail switch (for gun use on a pressure switch)— you’ll have to reverse the tube after modding a clicky tail switch (which you can ask for from Sofirn, and until you get it— borrow off a C8A/F or C8S host kit as I did).

Hope these few tips help for C8F builders— lots of these kits sold and they are very well made— but every build is different and these were my challenges. Good luck!

[eas]

Thanks for the tips. I should have one of these in a couple weeks. I better hurry and order the SST-40 emitters I want to use.

[pscal]

I have built 1 of these c8 triples and agree with everything Zappaman said! I kept nodding my head as I read though the pro tips!

@Zappaman

As I have suffered through a few of these C8F builds, here is some fast feedback for those cranking up their soldering stations:

1) take a drill bit (about a 3/16”) and carefully move the switch wires to the side while going in from the rear (driver side)— and ream out the wire holes from the back of the head’s heat sink. My first build was a frickin’ mess due to my 18g wires catching on the razor sharp edges left from Sofirn’s manufacturing of the host. I ALSO lightly reamed the FRONT edge of these wire holes too. I wasted my MCPCB on build #1 because the LED wires kept catching on these sharp edges, causing me to rip off one of the wires from the MCPCB trace completely— so making it unusable. I also pulled up the copper trace on the driver- but Lexel helped me with a second connect point (and… THANKS again Lexel!)

2) The tail cap bi-pass is pretty thin from the factory. I replaced mine as it came off (or shorted?) within the first few days of use. Good idea, but not well done at the factory (several others have had this failure too). So just replace it when building and be done with it!

3) Don’t forget the little plastic washer (used as a spacer) between the reflector and host’s front face— when you put that screw in— easy miss; and the face will not be square without it of course (how I figured it out— the hard way).

4) IF you use Lexel’s tail switch (for gun use on a pressure switch)— you’ll have to reverse the tube after modding a clicky tail switch (which you can ask for from Sofirn, and until you get it— borrow off a C8A/F or C8S host kit as I did).

Hope these few tips help for C8F builders— lots of these kits sold and they are very well made— but every build is different and these were my challenges. Good luck!

[Zappaman]

@eas

Thanks for the tips. I should have one of these in a couple weeks. I better hurry and order the SST-40 emitters I want to use.

Well you’ll need an MCPCB that will fit the larger SST-40- but DB Custom once wrote that Richard at Mountain had them.

PS. very happy with the SST-40 DK sent (in about 10 days) too

[eas]

Thanks for pointing out the MCPCB issue. I’ve been going around and around trying to find an inexpensive 26650 host for a reflector based SST-40 triple, I’d forgotten about that issue when I decided to just accept the battery size compromise.

I think I’ll probably end up cutting and drilling a copper sheet and gluing or soldering small individual XML MCPCBs to it.

[djozz]

I posted this in the WDYMT thread already, but has anyone else had the rotation-preventing screwhole in the reflector way off like this? It causes huge problems, had to ream the hole in the MCPCB and the cavity in the shelf to compensate for it, the build all of a sudden was not easy anymore thanks to a sloppy machinist.
(look at the bottom hole in the reflector on the right side of the picture. Already reamed the MCPCB, and because the hole is now in the trace area it was not easy to prevent internal horts to the core of the MCPCB)

[Mike_C]

@Zappaman

As I have suffered through a few of these C8F builds, here is some fast feedback for those cranking up their soldering stations

Thanks for the heads up. I have six of these hosts waiting in line.

[ZozzV6]

djozz I think you should contact with sofirn and they will send a replacement reflector.this is truly a big problem when assembling.

[djozz]

@ZozzV6

djozz I think you should contact with sofirn and they will send a replacement reflector.this is truly a big problem when assembling.

I think that they should be aware of the extensive consequences of that hole being off, but I’m not going to ask a replacement part for a host that only costed me 13 dollar shipped from the other side of the world.

[Zappaman]

Well, do what I do… let them know, then order another light and have them toss in a new reflector into the box- problem solved

I’d let them know anyway (and check your stock too).

[Talkatif]

Cissy from Sofirn asked me is it need to build triple with 26650?

“May i have a question? about C8F, did you think a 18650 battery is not enough to it? may have a need update to compatible with 26650 battery?”

What you think?

[contactcr]

@Talkatif

Cissy from Sofirn asked me is it need to build triple with 26650?

“May i have a question? about C8F, did you think a 18650 battery is not enough to it? may have a need update to compatible with 26650 battery?”

What you think?

21700 in my opinion. I also wish the reflector was secured with the bezel instead of that bottom screw that makes this thing so annoying to build.

[Satan (Satan@103TFS)]

Both 26650 and 21700 are welcome 18650 is too short runtime for this Amp.

[teacher]

I think a 26650 model would be a very nice addition.