[DIY] 3x XM-L U3 bicycle light project

Hi!

Here’s my first DIY flashlight project. It’s going to be light for bicycle.
It will be running 3*XM-L U3 1C leds, b3Flex driver and 4S2P 18650 batteries (14.8V 6000mAh).
Optics work will do this.. I truly hope that KD have listed TRUE dimensions of that reflector. Still waiting it to arrive and if it does not match to given dimensions… then i have to rework body/order other recleftor.

Assembly will go something like this:

- Clue leds

- Mount driver + solder wires to led

- Put battery&button wire throught cable clamp and throught body

- Solder b&b wire to driver

- Fasten pill to body

- Fasten cable clamp

  • Mount&clue reflector to body

I would have wanted to do other kind of mounting to reflector than clue/silicon, but with my tools it was not possible ( or just lack of imagination ).

I would need some succestions on how to mount this light to handlebar of bicycle. I would want some good and stiff mounting. Like troutie lights have. Anyone happen to know where I could buy those kind of mounts on web? I need to go throught local stores also, but all that I found so far was not so great.
Also ALL succestion to this project are welcome! I would appreciate that.

Currently I have made body and pill “ready”. They are straight from lathe, so everything is rought now, but i still have to do some grinding etc. so i polish them at the end.
Now I did found handlebar mounting for this light that suit my needs. Also did some polishing to body.

Tools that I work with are “kind of” big for this stuff. But if don’t look too closely, then it settles :wink:

Pill ( M30x1.5 fine thread )

Body ( PG7 thread at the end )


Full body


vs Sky Ray King size comparison

Now I’m waiting for parts to arrive.
Will keep this post updated with progress.

Thanks for reading and stay tuned!

Good luck on your build. Looks like a fun project.

Thanks, will need that :slight_smile:

I re-uploaded those photos to new server. First ones did not show up on mobile.

Its looking good so far. I'm looking forward to your updates.

Okay, so I did found bike mount to this light that suit my needs. It is some kind of “clock mount” for motorcycle. It’s perfect!! Pretty and shiny.

So I made pill inside that stand. Drilled hole and put 6mm bolt throught it for fastening mount to body.

Here’s photo off full body setup.

I uploaded also new photos to first post.
Can’t wait for parts to land, so I can fire this baby :slight_smile:

Wow! beautiful work. I can’t wait to see the progress! Good luck :slight_smile:

nice build
waiting for updates

beautiful build and fantastic machining, can’t wait to see it assembled. Nice clamp too. What’s the optic diameter? Ledil and Khatod do some very good 35mm triple optics if you don’t like the one you’re getting.

I would have invested a bit more in the driver though - something like one of the taskled drivers would have really put the finishing touch to this light. At least the one you’ve ordered has some kind of thermal monitoring though (presumably through that thick thermal pad?) as that’s not a whole lot of surface area for 3x XM-L@3A, especially as it’s polished so well.

There is nothing “locked” that I have to use that driver. I just made quick decision so I might get something before christmas. :slight_smile:

Body diameter is 55mm and lenght is 70mm. So that reflectors diameter is 50mm. I did look for those 35mm optics, but i wanted a little bigger and more mass to body, so it would be possible to handle 3A. After I had pill and body ready, I understood that i could have made just walls thicker and used that smaller optic. (This is what you get when you don’t plan nothing, just start making)

Might be that you are right and it gets hot, atleast it you don’t move. While riding, then i think it will handle the heat ( atleast in this –20C weather :smiley: ).

Thanks for pointing those taskled drivers. First time I hear about those. I’ll take a closer look.

b3Flex driver really seems like interesting. So much options and features. I have to really think of getting that one.

EDIT. Enough with thinking. Just read throught instruction for that driver and made purchase for it. Just WOW… Like “mattthemuppet” said, it surely adds great finish for light. Those options that you can manage are truly awesome. Can’t wait to get my hands on that.

it seems pretty decent and it’s the only one I’ve seen that will allow you to run 3S battery for a triple LED - most other people either use a 2S and a boost driver or 4S and a buck driver, each of which has their own disadvantages.

cooling is always a tricky balance - none of my lights have problems with heat during the winter, but I still night ride in the summer and my helmet light struggles when it’s hot and I’m slow :slight_smile:

blimey, you don’t hang around! They might be pricey but I haven’t yet seen a driver that ticks as many boxes as they do for cycling use. I have a couple of lights with b2flexes and 1 light with an H6flex (made before the b3flex came out) and the two I use for mtbing are set on threemode, so that each click cycles between med and high, with a long press to get back to low (useful for trailside repairs, finding your keys for the car etc.). They take a bit of practice to program, so give me a shout if you get hung up anywhere.

Pricey yes, but I would guess price to be higher when I first read that instruction. Programming that surely can take some time to handle. I’ll give you a call if I get stuck at somepoint.
Threemode sounds like good setup.

I’ll make extra pill that I screw first in body. While assembling the light I screw that extra pill to bottom of M30 thread. Then I add heatsink shim ( ordered one of these also ) to driver with adhesive and add some thermal compound on otherside. After that I screw pill to body and drivers heatsink should thicken to extra pill and transfer heat to body. That is what I planned now :).

Edit. BTW. What kind of clicky do you use with your lights? I was planning lockable clicky, but with this b3Flex driver I should use non-lockable. Do you happen to have some good suggestion?

Very nice job on the machining. I look forward to seeing the final result.

you need some kind of momentary (normally open) switch. for my bar light I have both an IP68 switch with a stat LED (for voltage warnings) and a remote switch I made with an old microswitch I had laying around. I :heart_eyes: remote switches. I think Judco also do wired momentary switches, which would make a remote switch a lot easier.

If you want only 1 cable gland going into the back of the light (you could always mount a 3mm LED on the body as a stat LED) you can use a 4 core wire and splice off the wires to the battery and to the remote.

Oh, and it will be worth thinking about a 4S2P battery, as the overhead on the b3flex will cause the light to fall out of regulation (dim) about 2/3 to 3/4 of the way through the battery discharge if you use a 3S2P battery. That’s pretty much the only disadvantage to using a buck driver for a triple XM-L.

Thanks!

Yea, I thinked also that 4 wire cable would be best option. Also like you said I thinked that i should get extra pair of batteries to get 4s2p setup.
I’ll start hunting right switch now. Thanks again for help :slight_smile:

Edit. And thank you Chicago X!

no worries! Looking forward to the finished light :slight_smile:

Still eagerly waiting for that driver.
But in the meantime I did got parts for switch and would like to share some pics and info about that.

Here’s parts that I bought
(ABS-10 host , 59P switch , 3mm led , PU5x0,25 cable , DA40 grommet and some velcro strap )

After making button hole little bigger and holes for starp ( also did put some silicone inside, so it’s waterproof ) - here’s finished switch.

neat remote, I like how you put the stat led next to the switch. It’s always good to see different approaches to remotes. I’m going to try and incorporate my next one into the brake lever clamp to reduce the reach, not quite sure how yet.

Thanks!

It’s fun to watch work of different people. All of us think individually, so you get good ideas from others :slight_smile:

Mounting to brake lever is good idea. Would love see how you make it.