So for those of you that are planning to buy a 21700 C8F host version and can’t figure out which driver to use. I can recommend Lexel’s narsilm driver. I had a 22mm driver that I grinded down until it fit. There’s plenty of room on the topside ring of the driver that it sits on the driver shelf without any of the driver components touching the shelf. On the bottomside of the driver, I added 3 solder blobs placed on the ring high enough that it just touches the retainer ring (I can post a picture later if people want to see it). Just remember to not put to much pressure when screwing in the driver retainer ring so that it cracks a 7135 chip (ask me how I know this).
Only problem with my light is that I accidentally ripped off one of the switch wires from the the soldering pad on the driver so now I need to try and fix it later. I emailed Lexel and he wrote me back how to get around it, so hopefully I can salvage the situation or if not I guess I’ll order another driver from Lexel.
The other problem I ran into was that I couldn’t figure out how to wire the stock switch to the driver. Luckily I had one of Lexel’s switch boards, it’s much easier to wire the switch when the solder pads are labeled. After putting the switchboard together, I realized that the leds weren’t bright enough for me (since the rubber boot is a dark color, anyone know if there are clear replacement boots that fit?). So I when I have more time I’ll go back adjust that as well.
I received mine, took nearly one month but Sofirn service was superb. Flashlight is a thing of beauty. Better than my former favorite, the original spec (3450 lumen) Jetbeam TH20. The 21700 battery combined with three deep-reflector well LED is so much better! :sunglasses:
I had a chance to go Turbo with the EFEST from Battery Junction. “Overwhelming force” is the thought that describes it. I have used the Jetbeam TH20 a lot with fully charged Sony VTC5A and Sanyo UR18650NSX. This Sofirn C8F 21700 with the EFEST is remarkably brighter. My dark, cavernous kitchen is lit up entirely, and into the backyard. It feels on par with the old Thrunite soda can lights from the year 2014 in terms of shock and awe feeling. Very bright. Perfect for pest control. Wish I had this over the Jetbeam TH20 when I was pest controlling food moths. This is just plain brighter, for longer, and covers a greater area. :+1:
Nothing yet. But I got my “thank you” C8F pack from Sofirn yesterday. It is a full pack 21700 version with battery, charger, 18650 tube. It has some issues but I contacted them and they are on it. Also as the low output problem of some lights. At first I also measured 2550 lumens with 18650 battery at first try but it was not completely full. Now with fully charged Sofirn 21700 it makes 3102 lumens. Temp regulation works fine. I measured 54°C on the head maximum and it stayed there while the light was adjusting output slowly down. My only negative now is the ramp characteristic. It maybe linear to current but not linear to the eye. The low side going up fast but the upper half barely changing. If they make an exponential curve to that like Narsil it will be a very good firmware.
Also like how they solved the two switch operation. It remembers the level and also if you leaved on or off with side switch. So when you press off and then On the tailcap it came back at any level you left or in a standby/off state.
So if have some issues. Don’t worry! It will be solved
I used my 21700 C8 last night on my Thursday night walk, the Samsung LH351D in 5000K 80 CRI looked really good in the night and the power level was really good as well. Enjoyed it a lot, sure to be a favorite among my user group and will make it harder to decide which light to grab.
Has anyone tested the temperature at different brightness at room temperature?
I have a C8F 18650: in 1500Lm its temperature is less than 55C, at 800-1000Lm and turbo 2500Lm after 20 minutes at 58C, at 650LM in 25minutes 55C. It turns out the most effective mode of 1500Lm and 2500Lm.
And how does the C8F 21700 behave?
Does anyone know if Sofirn will have the new C8F hosts without branding on offer? I saw that other C8s are available on their store aliexpress page without engravings and that would make that host much more appealing
Remember that you need a driver that takes an e-switch. The e-switch in the Sofirn C8 host is mounted on a board and held in with a threaded retaining ring, it’s all installed when you get it with the wires sitting loose in the head. But you need a 21mm driver that takes an e-switch. They provide the copper MCPCB that mates up to the reflector, you’ll need to reflow emitter onto it… XP footprint.
Yes, I did gather all that information, reflowing emiters onto the MCPCB would defo be quite challenging so it might not be stupid to ask someone for help with this later.
May I ask what drivers did you get for this build?
I built an Anduril driver with an ATTiny85 MCU and FET+1 set up, used a 17mm driver board from Wight, the A17Hybrid-S, and adapted it up to the 21mm opening.
