Sofirn C8F host. 21700 C8F Available

It’s a brass post on the switch but of course it’s loose and freely rotating in the metal housing of the switch body. Would be difficult to trim. The switches I have are much shorter, shouldn’t be a problem, but of the two of those I’ve tried on the board they just don’t like working with the boot.

Edit: I even covered the switch with Kapton tape with a small hole in the center for the post of the switch, thinking maybe the boot was causing problems through contact. Even tested the boot for continuity on my DMM, nothing there.

Edit II: About to try a shim, see if gaining a small bit of space makes a difference. The shim to be placed between the PCB and rubber boot…

I heard from someone that recieved 3 of the 21700 models and used a UT210E clamp meter and a short piece of copper wire as shunt.

1st unit: 8.0 amps < slightly less bright than C8F-18650
2nd unit: 9.3 amps = seems to be as bright (or maybe brighter?) than C8F
3rd unit: 7.6 amps < slightly less bright than C8F-18650

Can anyone tell me what the 18650 version drew? I think it was about 10A, right?

I would think the 21700 version should be drawing around 13A to 14A to get 1000 more lumen (3500lm), but we are way below that.

If anyone does happen to take their driver out, can you take some pictures of it and post it? I’d like to see what components are used.

So from the limited data we have would it seem to the more knowledgeable members that the 21700 version appears to be under-performing in general?

Just wondering if it could be a bad initial batch?

Yesterday I received my C8F 21700,
I measured only 2140 lumens, and only 6.07A at the tailcap.
Moreover when I step in turbo mode the brightness starts at about 1200 lumens and then slowly, in about 8/10 sec, it goes up to 2140 lumens, I do not think this is normal?

Maybe a stock of faulty drivers ??

Seems odd but even on a scratch built driver with a premium FET and 20 ga leads it seems to be under performing, even with Samsung emitters. Could it be the MCPCB itself? The pads on mine were pre-tinned but I added a small amount of solder paste before reflowing to be sure, got a wee bit of overflow so I feel pretty confident the emitters are solidly re-flowed on the board. I got 3100+ from my very first Sofirn triple C8 and that was even on their supplied cell. Only getting about that with this 21700 iJoy that a pair of them gave me 34A in my triple XHP-70.2 build.

So if it’s not the emitters, not the cell, not the wires and not the bypasses (I put a copper/bronze spring on the tail pcb with a 20ga bypass) then it doesn’t have a lot of places left to cause issue except the MCPCB itself. I should probably replace the hefty tail switch just to see what changes…

I used 18 AWG ledwires, Luxeon V leds, bypassed springs, a mini-GT driver and a Samsung 30T cell, and got 5200(3sec)4800(30sec) lumen. (until half of one Luxeon V stopped working, so a bit less now). That switch is about the best you can have in a flashlight, save for no switch at all.

Cutting the plastic washer out as a spacer didn’t help anything. With the spacer in place and the retaining ring on the light works fine, put the boot in and same glitch, mostly just a blink at the emitters and nothing.

This plastic washer was cut out of a credit card, I can feel the play between the boot and the switch post so I know the boot is not touching the post at rest. Still, doesn’t work. Works fine without the boot, just not with it.

The switch pcb is oblong, fitted into the switch compartment, and the switch itself is not in the center. So my plastic washer looks out of round but it is indeed true and matches the boot just about perfectly.

The above pic is with the light in lockout, holding the switch for momentary moon to show the sliced Samsung LH351D’s…

And now I ask, what is up with the design? Why did they not cut fins in the section above the switch? Only the opposite two sides have the new fins. Also, this one shows a slight shelf below the flat of the switch, was that a glitch or are they all like this? Don’t see the point in cutting that…

How about attaching some stiff plastic of the right thickness to the bottom of the boot? I guess that stiffening shouldn’t hurt. And extra thickness will make it touch the button at rest.

I get 11.76A at the tail with my Uni-T clamp meter, but only 3032 lumens out the front.

Edit: Remove the lens and it does 3236 lumens… the lens is costing 200 lumens straight up.

Edit II: Oh, and the amp reading is of course no tail cap, the lumens readings are light assembled with a large Omten switch on the PCB. (replaced the thicker stout looking factory switch)

Remember my post about the Times New Roman you love so much? :wink:

With a different lens and a 20ga spring bypass on the Blue spring, 3291 lumens at 12.97A draw.

The host’s are unbranded so I’m not seeing the relevance, assume they put the text there?

(also going to assume the actual font style would have nothing to do with that. :wink: )

I have both the 18650 C8F and the 21700 C8F and have just tried various batteries.

I use a lux meter app on my phone and get 460 lux on the 21700 C8F using a Liitokala 4550Mah 21700 and also using a 30Q with the adapter. I then used a Samsung 30T 21700 battery and got 560 lux. On the 18650 C8F I get 510 lux using a 30Q.

So the 18650 C8F does outperform the 21700 unless I use Samsung 30T’s.

How many of you meet less lumen issue? Sorry for that. We are working on it.

My 21700 C8F +sofirn 2700 4000 mah got a bit less bright than 18650 C8F +sofirn 18650 3000 mah from ceiling bounce test.

My 21700 sofirn c8f got only 7.22A used UT210E clamp meter and got 2,678 lumen. I use fully charge sofirn 21700 4000mah battery that come with the lights.

What is the price on the 21700 C8F? Are they still for sale?

This would be my first 21700 light and have always thought that the 21700 would fit the C8 better anyways.

It is under 33$ without battery at the aliexpress shop

I think you can get it for around the same price at Amazon with their coupon.

Also, know TA he may want to order 2x hosts for the same price from their aliexpress shop

Looks like my reputation proceeds me lol.