Add a tiny copper wire and see if it helps? They also anodized the driver side threads which im not a huge fan of. I think its better for heat transfer not to?
Lastly, my old 18650 sofirn bypassed tail switch broke and i probably havent changed that thing a dozen times. The wire was far too thin for how much solder they used.
Replaced the spring and bypass on that one and got 3,670lm at 0s with Samsung 25S. That one has LH351D 5000K 80CRI
Yeah, a simple copper washer should do the trick. Thatās easier than my first thought of building up solder and filing down the high spots.
The inventory in amazon warehouse is still the old ones, but it has code to bring the price down to $32 for kit!
if you donāt mind the lower output or can replace new driver, just PM Sofirn for code.
Does anyone know is 42mm glass will fit into C8F? My host came with lens with no coatings so want to upgrade but Iām not sure if 42mm one from intl-outdoor.com will fit or should I just get 41,8mm.
The ā42mmā one commonly marketed for the C8 fits fine, as does the stainless bezel if you fancy changing that too.
TBH I did order stainless bezel a while ago, just forgot about it, so the whole question was actually irrelevant :person_facepalming:
Thanks for the answer anyway 
I got new driver of 21700 C8F from Sofirn so I have 1 extra driver will order the host to built one with different LED but canāt decide which one to go XPL Hi for more throw or LH315D 5000K for 90 CRI ,what do you think ?
LH351D for the better color rendition and more flood.
Itāll be like a smaller Q8, so you will absolutely love it.
This is what is nice about this host. Either LED you pick will still have decent throw and flood but you can choose more of one or the other still.
More flood you say? Hmmm, what are the options for getting these leds? Can they be bought reflowed on a board or do you have to buy a host, use that mcpcb and reflow yourself?
You can reflow them yourself, but most of us, not including me of course, donāt have solder paste+temperature controlled hotplate. So it is out of the question unless you have it.
However, you can buy an MCPCB preflowed from Mtn Electronics, or even better, if you want a full light, buy this one, and select 219C version:
http://www.mtnelectronics.com/index.php?route=product/product&path=66&product_id=939&sort=pd.name&order=ASC
Leave a message saying you want 4000k 90CRI LH351Ds or 5000k 80CRI LH351Ds reflowed instead of the 219C, since they are about the same price He wonāt mind at all.
You can then put in the driver of your choice in.
Dang, he only has the 18650 version host.
I guess I have to buy a 21700 host from Sofirn and reflow the leds myself. Iāve got a cheap hot air station so I can clamp the mcpcb and heat it slowly from the bottom. Iāve got solder paste, but I think you can apply some wire solder to the pads, add some extra flux and then hot air to do the reflow. I need to watch more youtube hot air reflow videos. 
Thereās a first time for everything, right?
I need to do some reflo videos.
I think you can do it. You have done some mods Jason
Any codes available for this ?
Thanks,
Mike
Brite workā¦.
Nope, $37 with battery and charger or $32 without.
Wait for 11/11 sale and install Aliexpress phone app for additional discounts. 11/11 is the Chinese Black Friday
Replaced the tail spring (large blue) and beefed up the bypass (20 gauge) on my C8F 21700 w/ LH351D 4000K 90CRI
3,177 at 0s w/ lightly used Vapcell 3750mAh 24A 21700
3,486 at 0s w/ topped off 30T Vapcell re-wrap
They use so much solder on their spring pad I was worried I would kill the switch trying to get it off since I do not have hot air gun. I clamped alligator clips on both switch legs and it seems to be fine.
Going to call this one done.
Have one more host but not sure what LEDs I wanna use with it just yet.
Love this C8F hope the new throw version with single LED and bigger head. :heart_eyes:
(sorry pict to big have to adjust)
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Did you grind down the stainless bezel? What tools if so