Sofirn C8F host. 21700 C8F Available

Dale, thank you so much for the info man! I was hoping to get this C8F together tonight, but I seem to be out of 20awg wire. 18 gauge fits, but 22 gauge is too big for the center hole on the driver. I definitely want the least amount of resistance on this powerhouse so I’m going to assemble it tomorrow when I get some 20 gauge. :+1:

Edit: Reverse the 18/22 gauge wires and it’ll make more sense :person_facepalming:

Don’t you mean 22AWG fits and 18AWG is too big?

Correct you are!

Sofirn has sent me two coupon codes:
18650 version C8F
20% off code: 20QSPTUA

SF14
20% off code: 2045TU4G

Yourrid, I just bore the center hole out a little on the driver to accept the 18ga. :wink: just make sure the via is staying intact so the MCU can get power from the spring on the battery side, that’s how it works after all.

Alternatively, you can strip and tin the end of your 18ga wire and solder it into the via, then do a more traditional spring bypass on the other side of the board. That will work as well. Even a 22ga spring bypass will work in conjunction with the gold plating on the spring, should net just about the same as if the 18ga wire were run straight through. Very short span we’re talking here, shouldn’t make a lot of difference.

Or use the 20ga wire Richard put on the driver for your spring bypass. :wink:

Or remove the driver spring and solder a brass button (copper button) on the driver for a direct contact to the positive terminal of the cell used. Be sure to have a good spring on the negative end in the tail cap with at least a 20ga bypass there. :wink:

Dale, I actually started out with a drill bit thinking I could just slightly enlarge the hole to get the 18ga through. The next size drill bit I have is the exact size of the gold circle around the center hole. 18ga would be ideal considering this is a FET, but I’m worried of making the hole too big, or nicking one of the chips.

The driver only came with 22ga wires which weren’t attached. I also bought a replacement driver for my Convoy L6 and it came with 22ga as well. I went around searching for 20ga wires today but had no such luck; Hobby Town USA, Fry’s, Microcenter, Walmart, hardware stores. No luck.

I’m looking online now to buy some 20ga (probably need to use it on the L6 driver as well anyways), along with some Kapton tape for under the C8F’s reflector as a precaution.

I made the same kapton tape safety to reflector wire pockets and used 20GA in the XP-L HI build and it puts out 3300 lumens. Stock C8F driver, Stock tailcap spring bypass.

ZozzV6, I saw those pockets in the reflector and thought “I better be spot on with my soldering, or its time to invest in Kapton tape.” :laughing:

I’m hoping this FET from Mtnelectronics, XP-L Hi’s, 20ga wires, double spring bypass and some Samsung 30Q’s puts out some serious light :smiley:

They made everything locate off of everything else, the slots for the wire contacts, the hole for the screw that holds the MCPCB and reflector together, it all key’s together nicely. Even clears 18ga (but yes, keep it neat)

Run the wire from the MCPCB and leave em both long, run em out the end of the head. After you put the screw inside the head to snug the reflector/mcpcb assembly into the top you can then cut off and strip the two leads for the driver. Just tin the stripped end of the positive and solder it into the via. Solder the black one onto the pad, solder the switch leads to the driver, then sort of twist the driver/wires assembly down into the hole so the wires lay down in there. Press the driver into position and hold the end of the spring while you start the retaining ring. I like to hold the driver down in place until the retaining ring bottoms out, then watch that you don’t spin the driver too much more while you snug the ring down. Voila! Il Monstro!

Edit: You can use a screwdriver or pair of tweezers to wedge into the spring at the driver so it spreads open enough for you to get your soldering iron inside the spring, solder the 18ga wire into the via from inside the spring on the spring side, that way you won’t contact any components. :wink:

I, personally, think that flashlight modders should have been gifted with two sets of arms/hands. :wink:

Edit: Your photo, enhanced…

HAHA That’s what the Helping Hands tools are for right? :laughing:

I was thinking about adding some Arctic Silver Adhesive under the MCPCB as well. :+1:

Finding an online retailer that carries 20ga silicone wire and Kapton tape is slightly more difficult to find than I had thought.

Richard should have both, I bought the 2” wide roll from Richard a long time ago, I cut a square piece off (2” x 2”) and overlay the entire base of the reflector, then use an XActo knife to cut out for the screw or emitter openings as applicable.

20ga wire

10mm wide Kapton tape (all he shows at the moment)

I like to use Arctic Alumina Thermal Adhesive, if you ever have to remove it you can heat it up with a hot air station or hold the soldering iron to the board and once heated up you can break the bond. Arctic Silver Epoxy is more permanent, similar to JB Weld in it’s tenacity.

Looks like Richard is out of town for the remainder of the week. I appreciate the links! I didn’t realize he stocked Kapton. I’m going to put in an order for the tape and wires… and for the time being, use 22ga and some Arctic Silver Compound to mitigate heat until I can get it set up just the way I want it. Hopefully I’ll get to post some beamshots tonight between it and my “regular” C8.

Oh and thank you big time for showing me where to connect everything! :beer:

https://www.amazon.com/Heat-Temperature-Resistant-Adhesive-Electric/dp/B00W3FAFP0/

https://www.amazon.com/gp/product/B01AAX64EC/

Wouldn’t thermal grease be better than thermal adhesive?

Based on ability to transfer heat? I asked the same question last year: ” Thermal Adhesive vs Thermal Compound”:Thermal Adhesive vs Thermal Compound

As far as removing the MCPCB again later on down the road, definitely grease would be better for that. But I rarely go back and swap emitters once I build a light just the way I like it, so I just glue them assuming that it provides better heat transfer.

[quote=Yourrid
Based on ability to transfer heat? I asked the same question last year: ” Thermal Adhesive vs Thermal Compound”:Thermal Adhesive vs Thermal Compound

As far as removing the MCPCB again later on down the road, definitely grease would be better for that. But I rarely go back and swap emitters once I build a light just the way I like it, so I just glue them assuming that it provides better heat transfer.[/quote]

I needed to diassemble completely 3 times my Sofirn C8F modded light head because I got a faulty led.

Dang! Were those stock emitters or did you reflow some of your own?

My emitters. XP-L2. Two new and one used before. The one bad was at moon level even at turbo with the other two. Disassembled the light and reflowed again. I thought it was bad soldering. Outside of the light it was good. reassembled and worked for a few times but then moon from one led again. Disassembly and that one led only worked good if I pressed one corner of the dome. So it was some internal fault. Replaced with new led and now it is good.