Being a modder at heart, I just canāt leave things alone. I changed the Feedback sense resistor last night to .00833 ohms, stock is .010 ohms. Current input increased to 15 amps with a meter rated for 10 .
My lumen tube reported 3100 lumens at start up with a 30Q and slightly higher with a VTC6. S2 gets to hot to hold in about 30 seconds from a cold start.
Not really a substained usable turbo , similar to a D4, but lots of wow!
When I run the math for power in versus power out the lumens seems low to me. I would think that at around 6 amps or more to the xhp50.2, I would be knocking on the 4000 lumens door. Maybe the other losses are adding up like the lens. I straight wired (no switch, no tail cap) the bat to the tube and get very very close to the same measurement as with the tail cap and switch on.
Not the best host, by far, but Iāve got a mtn boost in an f13 with xhp50.2 and it fits the 21700 way better than 26500 ever fit. Had to do a 17-20 and a 20-22 brass ring, but it works great.
Beware, the shelf is paper thin on the f13. And the threads are way too fine. Decent host otherwise.
I was in the process of sanding the host down to fit an unprotected 26650 better, when I tried the sofirn 21700. I used a couple of the convoy squiggly adapters that fit 18650 in 26650s. Squeezed then on, no problem.
26650 hosts that will fit a protected cell will fit 21700 with simple safe adapters. 26650 hosts are also easy more prevalent.
Which brand F13 do you have? I think I saw several different brands when I searched.
I may just use a C8 since I already have a old one that needs a upgrade. It still has a old P7 in it for heaven sakes.
It was a 900 lumen monster back in the day. How times have changed.
Iāve got the ultrafire variant. This guy: https://www.fasttech.com/products/5273900 Itās āokā as far as hosts go. Convoy has me spoiled with the awesome threads and fit and finish. Ultrafire feels cheap, comparatively, in every way. If the 21700 had not fit, I might have scrapped it. Was getting to be more time than it was worth to properly fit the unprotected 26650. Was just too long a battery tube. Springs were loose. Shaking the light you could feel the battery moving towards each end. Smooth reflector is about right with the beamshot in the ad for it. Nice round hotspot, well defined, with a less dense corona. OP would have been way better, but i havenāt been all that confident in what i think i sourced from KD, so i never ordered it.
I also have a clear convoy c8 with the MTN boost driver and 50.2. Handles the heat surprisingly well. I love that emitter in that light. OP reflector made it just about perfect.
Also tried it in the M1 with the same driver. And a s2+ tooā¦ Happy with both. Swapped the 50.2 for a 70.2 in the m1. DANG. If youāre thinking about it, do that. More floody, a bit more output in comparison.
Had to ream the reflector out a bit and add some kapton tape, but it was worth it. I ordered a few 70.2 gaskets. Iāll remove the Kapton and fit them later on.
The extra power of this driver would be awesome, but iām not ready to flow a whole board yet. MTN has us covered in the meantime with his boost drivers. If the 20mm kicks out more power, iāll be all over those too.
If gxb172 in 20mm version exist (it look like loneoceans have it, but I don't think he has the pcb released yet?), then it would be good for another flashlight which take 20mm driver! Mr. nkresho, is the f13 light a 20mm driver use?
From the third pic from the right at fasttech it shows a retaining ring in the bottom of the head, its possible this fits a 17mm driver.
Nkresho can you check the measurement to confirm that.
Wait a minute he said he has a mtn (17mm) boost driver in it now, so yeah 17mm fits.
I put a mtn boost in a convoy m1. Before that had zener 2x18350 fet. Used a 70.2 and a step drill bit to open reflector. Gave it away as a gift but i really liked it.
Just to give some perspective to just how tiny this temp sensor is I took a pic with a 7135 laid out beside the temp sensor, most people know about how small a 7135 is. I canāt even see the reference dot without magnification. I held the actually board up to my screen and measured the width, this pic seems to be about 7 1/2 times bigger than the actual size. Split that temp sensor in to about 7 parts across 7 parts up and down, take just one piece, and that should give about the actual size.
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Made a copper stud for the driver for a better less resistance connection.
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I do not have same skill as you have or copper wire, so I use a cable terminal and shape it to fit. Size is 5mm long and 4.5mm wide.
Tip to beginner - I use needle-nose plier to open and close brass ring. It does not fit well so I made a lot scratches, so I recommend getting thin-tip pliers to open and close retaining ring. What method do you use?
I have the straight version and it works fine. Though I do have a nice stiff hardened steel pair of curved tweezers I have used to screw/unscrew pills and rings. I use those a lot then do the last bit of torque with the above pliers just cause the tweezers are less bulky and I can use them for more things.
Capacitor C15 when installing the original ring will hit the ring. You can take a round file or convex file and file around the inside of the ring for clearance of C15, filing changing the angle on the ring from the top to where the ring contacts the driver. Try not to take material around where the ring connects to the driver. C15 is the only component that is anywhere close to the ring. Filing clearance, eliminates the need for a added copper wire around the driver ring.
I would suggest something like this for $5 to $10 locally.
You can use the tips without the pliers to get good twisting torque. Plus you can both squeeze or push apart the tips depending on the type of bezel you have. They are the flashlight modders best friend.
I changed the Feedback sense resistor last night to .00833 ohms, stock is .010 ohms. Current input increased to 15 amps with a meter rated for 10 
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Tip to beginner - I use needle-nose plier to open and close brass ring. It does not fit well so I made a lot scratches, so I recommend getting thin-tip pliers to open and close retaining ring. What method do you use?
