Wow that looks like a tough build!! 
Hey folks. RMM added a parts kit for the 4-layer board. Pretty excited about this little buck that could so I had to order.
Remember if you order the parts kit it isnāt an SOIC8 Attiny, so itās a little harder to flash. I made the mistake of ordering the mcu bare
What would oneās āIdeal buildā be with this driver? Host? LED? Battery config? Looking for some ideaās?
UF 1405. That light rocks with a good driver in it. 5A constant current until the two 26650s are dead.
Thanks Richard, sounds like a winner!! 
This driver is awesome in the 1405. I've been playing with one of RMM's four layer buck drivers set at five amps in a 1405 for a couple months now and the driver has held up flawlessly. The four layer MTN MAX combined with a dedomed XM-L2 in the 1405 lights up the treeline out back of my house at 500 yards easily. I'm guessing it will do twice that range but I haven't confirmed that. I've also put one of RMM's two layer MTN MAX drivers at 3.5 amps into a mini mag running triple XP-Ls. That was a cool little light.
SOLD! Got one on the way! :bigsmile: Tend to dig lights that ROCK!!! 8) Oh it should really ROCK with the XP-G2 S4 2B de-domed!!!
You should see about 480kcd out of a 1405 with an S4 2B at 5 amps. Ask me how I know.
Thatās cool! I am waiting for my parts from Richard to arrive but I am going to push the dedomed S4 2B at āonlyā 4.5A for reliability concern. How much candela would you expect at 4.5A?
I donāt know, maybe 425-450kcd.
could you take some long distance beamshots of that white laser ??? I would love to see what this driver can do in a 1405!
Iām using a different, lesser quality 5A buck driver. I have yet to do one of the MTN-MAX drivers, but performance should be the same/similar.
Iām building my kit now. I think Iāve figured it out by process of elimination, but āCMAXā is the Buck IC bypass, right?
Correct. Make sure you get the thermal pad on the buck IC reflowed fully.
ohā¦
lol wish I had read this before I just soldered the thing into the pill
I think Iāve got it working, but next time Iāll just order the completed driver. I can deal with all the caps and tiny resistors, but I hate these components that have the pins under them.
I have the c682 coilcraft inductor. At the bottom it has 2 contact plates on each side and a black pad in the centre. I presume the black pad is the termal pad? Richard mentions one has to reflow the thermal pad? On the pcb underneath the black/thermal pad theres silkscreen, no place for reflowing? What is meant by reflowing the thermal pad of the inductor to the pcb?
Mmm, I realize now the thermal pad is that of the buck IC, not the inductor. Apologies! Please ignore my comment.
Some SMD parts have solder pads not exposed or visible with the part in place and these canāt be soldered using an iron but need a hot air reflow system, a reflow oven, or some way to heat the entire thing up to the solder melting temp. For some things you can use a hot plate and carefully monitor it but two sided pcbās can get tricky if it has such parts on both sides. Otherwise you could reflow the difficult part first and then solder the remaining parts with an iron.