Total head length (without bezel screwed on, measured from the edge of both open ends of the head = 57mm
33.5mm depth to the heat sink milling (from bezel threadās edge on front of light)
13mm from tube entry to the face of my driver (screwed in)
Thus 57mm less 46.5mm leaves 10.5mm from the SPRING side of my driver, the the FRONT face of the pillbox (back of the MCPCB).
Given the heat sink behind the MCPCB is approximately 4mm (a close guess), that would leave you about 6mm to work with for the 1/2 of your driver that would need the space in between the driver mount area and back of the pills heat sink (back of the head)- PLUS wires. My driver is about 5mm thick and there was a LITTLE play to work with the 18g wiresā¦ close to maybe 3-4 mm of play.
I have another C8s host coming in a few weeks and I can measure it more precisely then. But there are ALSO no threads left to back the driver out eitherā¦ I got a good 3-4 turns on itā but the retaining ring is still not quite flush with the start of the headās driver threads.
So the driverās board thickness could not be much thickerā¦ and converselyā¦ could not go in any more shallow that my driver does sit.
So sadly, my best guess is āmaybeāā¦ sorry :weary:
Soā¦ Iād try it and if itās a no-go, then just grab another driver (thankfully there are some good ones that fit!!!). I bi-passed the tail and tweaked the Bistro HD and this light really is a great little bright light (and medium thrower), with just enough spill to be usable for all-around use. Iāll build another (#2) Sofirn C8s host with the same SST-40 (de-domed next time) and another one of Lexels Bistro HD TA driver- that he confirmed will draw up to 8 amps off a good 18650- and that puts this LED at HIGHER output (2500 lumens) than the xpl HI at the same current domed or de-domed :smiling_imp:
Could one of you kindly help with another measurement? What is the diameter of the opening underneath the driver? That isā¦ how small of a driver will fit without falling through?
I ordered on the of the Sofirn C8 hosts (the one with the 17mm driver opening) and love it. Well, that is until I found out that I canāt fit a typical nanjg105c driver in it without extensive modifications. The 7135ās interfere with the driver retaining ring (much like on an S2/S2+). A single sided driver works great, but Iām wondering if I can fit a 17mm driver will hold tightly in the 20.8mm version without it falling through.
Side noteā¦ what LED gaskets/insulators does this one come with?
My calipers canāt reach in but eyeballing it very close Iām getting .732ā/18.6mm ID. Not much ālipā there unfortunately (on my spare host anyway). So the 20.8 host wonāt work.
Butā¦
I grinded my C8F retain rings to almost 1mm thick (at about a 35 - 40 degree angle all around) on the driver contact side of the ring when I installed Lexelās NarsilD TA 17mm drivers- and your problem sounds JUST like mine did. Lexel suggested the ring grind and also said ācarefulā light sanding on the chipās edge (just a touch) is okā But just to relieve pressure. I decided to just grind the ring as far as I could and it worked out nicely. 1st driver, hand file and 30 minutes; 2nd driver dremel and 2 minutes :+1:
Might try that trick if you can seat the driver. Good luck!
If you havenāt done the ring grind trickā¦ Why donāt you measure the width of the chips edge on that driver and send it to me and I CAN compare to my 17mm Narsil TA driver (I seated in the 17mm C8F host)?
I pulled my 17mm driver out of my (work in process) C8F and the distance from the furthest edge of two opposing chips (measured on their corners) is 15.58(ish) mm. I did sand the corners of my SIX chips on this driver- just a tad and after the retaining ring āgrind boogyā- it all snugs down perfectly (with more like .8mm left ON THE DRIVER side of the ring).
Looking at it, I could have gone deeper (to about .5mm left) on the driver contact point of the ring. But as it is, my chips are not touching the ring with any pressure as when I tighten it I can tell the pressure doesnāt start UNTIL itās seated within 1/4 turn.
So, you may be able to use the host you have in the hand Cross my finger for ya!
You can get a washer with the right-sized hole that the driver would just barely fit onto (not into), and if not bought as such, shave down the outer diameter to fit the hole in the lightās head.
Eg, to fit a 17mm washer into a 22mm hole, I got M16Ć22Ć1.5 washers. 16mm inner hole lets the 17mm driver rest on a Ā½-mm ledge, and that drops into the 22mm hole in the light.
If you have some step-bits, you can use it to ever-so-lightly bore out the ledge to keep the driver from sliding around. Solder the driver in the washer. Then you pretty much have a faux ā22mmā driver.
I have had some long waits from Sofirn, but IF you see the listing with the circled text here:
ā then itās usually faster from AE.
My last Sofirn light order for several lights had a few models āhandled by AEā (during the AE anniversary sale on March 29th), they got here Monday. So that was just 12 days which is blazing speed for anything from China. So I went and checked and several older orders āfulfilled by AE)ā have also come faster- twice as fast on average than if shipped by the seller.
Of course there are no guarantees and Iām not sure if the C8T is sold through this AE shipping network (the one I bought during that same sale was not; still waiting for it). But there were several places they list the SAME light sometimesā and I now think that might be because one is local to the seller, while the other may be āhandled by AEā.
Anywayā¦ a tip for anyone buying anything from AE (FWIW).
Not flashlights, but I also bought some stuff on 3/28 for the anniversary sale from multiple sellers and the orders have been rolling in this week - even with the slow (non ePacket) shipping. Thatās like 8 business days (10 if you include Saturdays)ā¦ some of the fastest shipments Iāve ever had from China (outside of DHL stuff).
The SP10As and SP32s that were āhandled by AEā were in the Monday box (yes, it came fast!)
Andā¦ the SF31s are not in the US yet (of course). Qidong (at Sofirn) sent me that pic I posted above and confirmed AE handled deliveries were faster.
I am still waiting on an order posted March 12th (no tracking updates for over four weeksā then today itās in Kansas City suddenly)!
EDIT: (9 hours later) -ANDā¦ I was even MORE surprised to FIND this old, almost forgotten order in the mailbox later TODAY!
I also ordered some more Sofirn flashlights. The āhandled by AliExpressā arrived very fast (almost like expedited shipping) in my country too (less than 2 weeks from ordering). My other Sofirn flashlights (not āhandled by AEā) are just leaving China, based on tracking infoā¦
The new Sofirn C8T I re-ordered, still comes only with non-AR coated glass lens, despite the manual stating it uses āAR-coatedā glass.
(Ok, I understand thereās very little brightness difference with AR vs non-AR, but I would think they have fixed it since they last mentioned it.)
So I ordered the AR lenses and I must admitā I couldnāt see any coating as I easily see with others. But Sofirn claims itās coated and I did replace my January kits.
IF YOU LOOK AT THE OLD LENSESā ON EDGEā¦ you will see they are green (like old Coke bottles- light, frosted green) whereas the new lenses are truly clear (and look thinner by a hair)
My newer Sofirn C8* lights (since mid-March) DO have the clear glass (including the FOUR more C8F kits I ordered) ā but I have no way to test except to try each outside some night. I guess Iāll do that and see if I can tell a difference. Jury is still out.
I still need to compare some lights here officially, but until I get my camera fired upā¦ I DID finally get my C8T in a few days ago.
I compared it to my shaved SST-40 in my C8(s) Sofirn host built (with Lexelās Bistro driver delivering 7-8 amps to the SST-40) and I have to say this C8T frikkinā keeps up! I was expecting the long throw, but the general output (compared to the SST-40) is all around as good; and I actually prefer the warmer tint of the C8T. I spent about twice as much to build my SST-40 mod, and the Bistro UI is quite nice, but againā¦ the C8T is impressive in many ways and quite the equal to my custom light here.
I also love the C8A and when I get some fully charged batteries, I plan to compare the C8T and C8A both, and also check them against my C8F (with shaved XPL V6ās). Again, need time and some topped off 18650s- coming soon!
Myaā I suckā¦ Spring (finally) hit here in Kansas and suddenly Iām out-of-time during darker hours (in bed). I am also chronically waiting for parts.
Iāll get my arse out there soon though. Iāll go for comparison beams between the C8T, C8A, C8F and Q8. I had driver issues with the shaved XPL version of my C8F that also is causing a delay- but Lexel is working on it. But I can build the same shaved XPL light out to a DD (which was the plan anyway- for gun use).
But for testingā¦ Iāll borrow another C8Aās clicky tail switch (so not using the FET tail pressure switch for testing as it would be cumbersome). As Iāll be bypassing the side switch for this C8F gun light, Iāll otherwise use Lexelās FET pressure switch when on the gun of course. I just need a rainy day or two to get me sitting at my bench with the solder station, then a night on the back deck with some camera I also need to dig up.
For now I can say the XP-L2 version of my C8F (the one working one with Narsil driver) has a good flood, but the throw isnāt as good as the shaved XPLs (I briefly tested with a problem driver now back at Lexelās shop) I did finally get XPL HIs (V3s) also in (just a few days ago from KD- they are taking forever lately BUT they do eventually get here so fair enough). Iād like to build THAT light tested against the shaved XPLs (V6) ā with Lexelās driver I hope to get back and working soon.
Anyway, if I had all the parts, it would be easier to āgeter doneā
I got my C8T in two days ago, and holy crap the throw. Very yugeā¦impressive length. Iāve probably annoyed the neighbors with the spill alone lol. Jokes aside, Iāve easily and brightly lit up trees that are 825ft away, passing itās 250m rating with flying colors. The reflector is gorgeous too. Iāll be testing it tonight while Iām camping, but itās impressed me so farā¦
Cross my finger for ya! 
