[NMD] Convoy 3x21A with 3x FFL909A 4000k

This was a mod I had been planning for a while, but it requires orders of a 3x21A host, 3x21B host (for reflector), Convoy 25A buck/54A FET driver, FFL909A 4000ks (which are stupid expensive now), 9090 MCPCBs from Kaidomain, 40mm & 50mm copper blanks, plastic screws and washers, and a lot of titanium drill bits…

When all these ingredients combined, it produced Mk I, which can be seen in the later photo with the JB Weld muck on the seams. I used unmodified 25mm MCPCBs stuck together with JB Weld HighHeat, and tested alignment with a Convoy 3x21A smooth 3x 5050 reflector. I assumed the alignment would work the same for the OP 3x21B reflector. But you know what happens when you assume… The alignment was pushed out about 1mm too much, with left a donut hole in the beam because the LEDs were not centered and nerfed the hotspot. It was still a flood beast but it just was not artistically pleasing.

After a day or two of working up the nerve, I disassembled the flashlight guts and tried again. By "guts" I mean "the monster", a 40mm x 2mm copper blank with 3 perfectly spaced holes drilled in it to fill the MCPCB slot on the 3x21A soldered to a 50mm x 2mm copper blank with 3 more perfectly spaced holes (which took 3 a few time consuming prototypea to achieve) to serve as a base plate for what I finally did. It had to be 4mm total height to make up the difference between 3x21B 30mm reflector height and the 3x21A's 34mm reflector height. Finally, I filed down 3x 25mm 9090 MCPBs and meticulously checked them against the reflector as I soldered them to the baseplate too, and then reflowed the FFL909As onto this mess. Lots of going back and forth between hot plate, cool down, test, repeat. And I ruined about 4x FFL909As in the process by chipping or frying them.

I also discovered my improvised reflector spacers in Mk I did a crap job of preventing the reflector from cutting into the LEDs, because there are no adequate 9090 gaskets that fit a 7070 reflector hole and don't obscure the FFL909A LES at that. I improved on this by drilling into "the monster" and uses plastic screws and washers at strategic spots to elevate the reflector hovering above the LEDs in the right place… Success!

The result of this tragicomedy process was Mk II. Almost perfectly centered LEDs which mostly got rid of the donut hole on the beam while also giving a more pronounced spot.

Guesstimating about 20k+ lumens of rosy 4000k goodness when powered by Reliance RS50. Total lumens looks pretty close to my 3x LHP73B 4000k mod, but the beam is a bit floodier for the FFL909A whereas the LHP73B is throwier, but the rosiness is far more majestic.