This is a special one, nearly all of the parts were made possible through other forum members in one way or another.
The light that BLF built:
Host | Sofirn C8F 21700 (host version avail. thanks to BLF) |
Spacer | Prototype AL spacer from kiriba-ru |
MCPCB | LED4Power 3535 ANNA6 |
Driver | Lexelās 21mm C8F version TA FET+N+1 includes more clearance for the retaining ring |
Optic | Ledil ANNA-40-7-S |
Springs | BlueSwordās BeCu spring |
LEDs | 3x LH351D 4000K 90CRI from AEDe group buy 3x LH351D 5000K 90CRI from DigiKey |
Some quick measurements:
18650 VTC5D
21.x amps
5,693lm at 0s
21700 VTC6A
5,851lm at 0s
21700 30T
6,479lm at 0s
22.5 amps at ~30s
Pictures:
Sloppy re-flow I had to do twice cause I used way too much solder paste. Itās hard to ātapā excess solder from 6 LEDs, 2 pads, 1 jumper in a reasonable amount of time. Note I jumpered the FET and left off the LD-x4 specific parts (temp sensor, FET, JST connector)
The C8F usually has a small tapped screw hole in the middle which holds the reflector and MCPCB to shelf from underneath. I drilled it out with a 15/64 bit, I could have used smaller but I left it big in case I want to add larger LED wires or use the signal wires if LED4Power releases and e-switch driver some day. In this picture I have a small blue spring but I ended up turning it upside down cause I think itās too tight to prevent shorts this way.
Donāt forget your TWO layers of thermal paste. You could use thermal adhesive but I have no balls. Also, the spacer has some play so you would want the whole stack to be centered first if you went this route. You could also hold it like this if you have trouble soldering the LED wires but I didnāt bother. Those coated pads + a big honkin chisel tip will do the job.
Since iām using a 7 LED optic on this 6 LED board the wire placement is something you need to fiddle with. The unused center TIR caresses your wires lovingly.
In order to seat the optic all the way down the edges press right up against the head of the light. If I remove the bezel again I will probably have to wedge the TIR out with a screwdriver. If thatās the case I think I will sand the TIR slightly to give it more room. Itās terrifying screwing on the bezel snug. Everything rotates some and I worry I will either crush something or bunch up the LED wires. I did it anyway, YOLO. It survived.
I did some tint mixing since I didnāt have 6 of the LEDs I wanted to use. The beam is nice, there is a defined and very even hotspot. You would never know the middle LED was not used. I suspected as much since Ledil makes this same optic with 3~~, 4~~, 5~~, 6~~ and 7-lens versions.
I had zero issues testing with various 18650ās but when I moved to 21700ās I ended up shorting something and melting a blue spring in seconds. This is when I put a new one on but this time upside down. I think my tail spring is too long and stiff also so I will play with cell spacing and refine this.
Heat doesnāt seem to be a big issue and not using DTP for the MCPCB seems fine as well. Further testing needed here as I only tested turbo in ~1m increments. The light never got too hot to hold even after several 30s-1m turbo runs with a 30T. There is a lot of mass in this thing after all.