Skylight's entry to the 7th BLF Old Lumens Contest 2019 - modified light category [Matainvoy ML18S FINISHED, video added]

Some more info about the flashlight

The Matainvoy ML18S weighs 862g empty and 1042g with batteries. To compare, the Astrolux MF01S weighs 702g with batteries and the Convoy L6 582g empty and 774g with batteries. So it is heavier when empty than each of the other two with batteries.

The weight is concentrated on the head but I don’t consider that a problem as you will hold the flashlight anyway at the head where the switch is and the long battery gives some balance. It might be too heavy to carry around for longer use. The copper spacer I have added to the head weighs 310g with the thick wires and is maybe 280g solid copper.

The thermal transfer works well. After maybe 20s on turbo you can feel the head spreading from the bottom and the top of the head where the copper contacts the aluminium body. The whole head heats up slowly and evenly especially when all the copper was cold. On the other hand it also stays warm for a few minutes after a few turbo bursts.

Towards the end of my video you will find a tailcap current measurement. The clamp meter has to adjust the scale to the next level when you turn on the Turbo with a double click. I have never seen this on any of my flashlights before! With two fully charged golden Golisi 26650 4300mAh, capable of 30-35A discharge and as mighty as a 30T, the current is 17.6A on highest ramp and 29.2A on turbo. That would be around 3A per led and if you use four 30Q’s in a MF01S with 15A discharge the leds wouldn’t get much more. Of course the runtime is reduced but after a few turbo the batteries were still at 3.9V. My estimate would be around 15 000 lumens for the ML18S.

I had both the ML18S and the MF01S together on turbo with full batteries and I can tell you that the MF01S heats up faster. When you don’t feel the heat on the ML18S the MF01S is already warm at the head. I assume that my flashlight would run a little longer on turbo while heating up the 300g copper spacer but it will step down, considering also the voltage sag on the two 26650 at 30A.

Beam and tint

The tint is a bit green at low levels but without a direct comparison you won’t notice it. The MF01S with 4000K SST20’s is slightly rosier and warmer. The tint mixing of 4000K and 5000K LH351D’s gives you around 4500K.

The beam is wide and uniform. It has a big hotspot, maybe twice as big as an MF01S as you can see in my whitewall beamshots. This big smooth hotspot almost reminds me of a zoomie and as I like zoomies I love the big, floody beam. The throw is not bad and it reaches out 150m easily. It is the floody sister of the MF01S and where the MF01S throws further with a smaller hotspot, the ML18S impresses with a huge and blindingly bright big hotspot with not bad reach.

Most challeging task: Cutting the copper and leveling the copper spacer to fit well

Easiest task: Changing the switch cover from black to transparent :wink:

Most satisfying thing: Seeing the main leds and aux leds light up for the first time

Some things I have learned: Soldering with low temp 138°C solder, using a hot plate, soldering a 300g copper spacer, connecting aux leds and maybe some more things I forgot to mention.

The Matainvoy ML18S will always be honored by me as my first OL-contest build and hope fully not the last.

I would like to round off this thread with some acknowledgements.

Thank you, Lexel, for your great drivers and custom aux led boards. Thanks for your fast answers and useful explanation. The ML18S would not have been quite as great without an Anduril driver and an aux leds Board from you.

Thank you, AEDe, for the LH351D’s that I got from your group buy. It was perfect that I could get some in 4000K as well. The LH351D’s are astonishing under an MF01S optic and give the ML18S a really nice beam.

Thank you, BlueSwordM, for your great BeCu springs. They do an excellent job in the ML18S and allow it to handle the 30A current with ease. Thanks also for the FD2 SST20’s that would have taken the 4000K place in the tint mixing if I wouldn’t have been able to buy 4000K LH351D in time.

Simon Mao from Convoy deserves a mention as well because he designed the Convoy L6 which was my first over 1000 lumen flashlight and is still one of the nicest hosts I have. I just had to have another one in brown even though it was not from Convoy but from Wainlight.

And finally, many thanks to all the BLF members for organizing the OL-contest, for encouraging the participants and for the nice welcome every one who joins gets.
Many thanks to everyone who followed my thread and left some kind and encouraging comments but also to everyone who read my comments and looked at the pictures. I felt like being a part of BLF more than ever before. :partying_face:

I’m glad I have joined the 7th BLF Old lumens contest and I am really pleased about the outcome, my Matainvoy ML18S. :+1: :laughing:

Well done on completing your build :THUMBS-UP:

Awesome video of a really great mod. Thank you, I really enjoyed watching it. And, to my surprise, my wife watched with me. :slight_smile:

Congrats for realizing that one, very good job and great result :+1:

Lots of bits and pieces disappeared into that light Skylight. Not sure how you managed to fit it all it but nice work. :slight_smile:

Thank you, Agro. :slight_smile: Great that you liked the video. I supposed it would be interesting only for modders and flashaholics but it is nice to hear that also non-flashaholics can watch it. All the one, two or three minutes clips cut together turned out better than I expected. This is actually my first Youtube video. :partying_face:

Thank you for organising the BLF OL-contest. :crown: It was great to be a part of it and it lets you feel the spirit of BLF. So many people are watching, write nice comments and that is very motivating.

Thank you, man of light. :sunglasses: This mod could be nice for others to try as well. I really like the result and I’m relieved that I managed to complete it all.

Thank you, MRsDNF. :smiley: Yes, you are right, lots of copper, lots of cables and lots of leds. :smiling_imp: I was lucky that the driver cavity on the L6 is rather big and you can fit in all those cables.

Skylight, I maybe missed something. It looks like the driver is a FET driver, not buck. Is the MCPCB wired for 2S9P configuration of the 18 LEDs (some sort of 6V board)?

Yes, it is a 2S FET driver. The MCPCB is 2S9P and can be directly used with 6V. I got it from the Mateminco store on Aliexpress.

It is the new MCPCB that they are using in the Mateminco MT18S or Astrolux MF01S. The 6V board is designed by Lexel as it is written on the board. The old version, the Astrolux MF01 or Mateminco MT18, used the other board with 6S and boost driver.

Banggood is still selling the old MCPCB with Nichia 219C but the Mateminco store has got the new version that is 2S stock and much more convenient than the cable mod.

Cool, thanks - I’d forgotten Astrolux did all their four-cell carriers as 2S2P, and was thinking of it in my head as a 4P light.

Amazing build! Congrats on the win!

Thank you, The Whispering Gallery. :partying_face:

Good luck with the prices, hope you get one you like. :sunglasses:

Wow!! This is an incredible mod, and very inspiring for me.

Quick question (sorry if you answered it in the thread, i just watched the video)

How did you ensure the mcpcb would lay flat on the “shelf” after you soldered in that (amazing) custom made copper heatsink? Im assuming with the copper braid you had uneven edges that were not flat the whole way around, did you sand?

I ask, because i am installing my first new driver soon and i will need to use copper braid and solder like that to fill the gap to the host, as the driver isnt wide enough in diameter. And i am going to need to make sure my battery tube makes solid contact with the driver.

Thanks, and great job, really! I would love to make a build like yours, i’m assuming the heat management is off the chart compared to the original mf01s!

What’s better than 1 led? 18 leds!! :open_mouth: Hey nice work brother. Must of clocked overtime on this one! Can I send you mine? :stuck_out_tongue:

Thank you, Artiet59. Nice to hear that this mod is still not outdated. :slight_smile:

The copper braid indeed had uneven edges but they were pressed down by the MCPCB as I put the copper braid loosely with some thermal glue. The thermal paste and the optics are holding it down well. If you are enlarging a driver I would use solid copper wire, soldered to the driver.

It takes quite a while to heat up the copper spacer. I never ran this flashlight more than 5 or 10 minutes and mostly only at the Anduril ceiling level which is pretty high at around 17A. In winter it only gets warm on the outside. It it true that the MF01S heats up much faster but I suppose the LH351D are also running cooler than the SST20.

Thanks, Hank33. This flashlight mod was worth all the work. Considering the cost it would be cheaper to straight away buy a MF01S. It would require a very good reason to convince me to build the same flashlight again. :innocent: My next L6 mod might get four XHP70 in a quad reflector.

Thanks for the response! OK, that makes sense you used thermal grease and didn’t solder it. And thank you for the info, i do have copper wire so i will definitely use that instead of braid if you recommend it. I wont be able to hot plate solder it because i dont want to remove the spring, so i will test my solder skills lol, but it will probably be smoother then braid for battery tube connection. thanks Skylight!