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

Looking Good ” Skylight ” :+1:
Cannot wait to see more :smiley:
I like the 18 gauge wire, some of my lights need that too.
Also you have a sweet hotplate too ” UYUE 946-1010 LED Display Preheating Platform ” :+1:
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Thank you, CNCman. :sunglasses:

Yes, the hotplate works well and is definitely needed for soldering a 300g copper spacer. :smiling_imp:

The date at the top of each post represents the actual day when I have worked on the flashlight. It is not that I have finished it all today.

02/19/2020

- Tested the length of copper needed with a stack of copper coins (2- and 5-Cent coins)

- Cut three 3cm pieces from the 16mm copper rod

02/21/2020

- Soldered the three 3cm pieces of the 16mm copper rod to the 6mm thick copper plate. I had to file them a bit to make an even surface for soldering.

02/22/2020

- I prepared some thick copper wires to fill up the empty space around the copper spacer inside the flashlight.

- Removed the black ring in the switch cavity and fitted the switch inside with a little filing.

02/23/2020

- Removed the anodisation from the parts inside the flashlight that will be in contact with the copper spacer. This may improve the thermal contact.

- Also, I drilled a hole in the copper plate where the wires will pass through. The ‘legs’ of the copper spacer needed some filing to maximise the contact surface with the flashlight body. With my hand saw they got a bit different lengths and are slightly crooked.

- Soldered some 30 AWG wires to the switch and prepared 28 AWG wires for the aux leds.

- The silicone switch cover needed to be shortened a bit, otherwise the switch wouldn’t have worked.

02/23/2020

- Soldered all the wires and assembled the head with the switch, copper spacer and thermal paste + glue

02/24/2020

- The thermal glue had time to dry overnight with the flashlight closed and thin foil to protect the MCPCB from being glued as well.

- I tested the aux leds with the multimeter. Looking nice. :heart_eyes:

- I put the MCPCB in place with some good 10 W/mK thermal paste underneath and connected the wires for it and the aux led board.

At the first attempt the aux leds did not work, only the green lighted switch.

02/25/2020

The next day I send Lexel a PM and he told me to connect the aux led board directly to the battery voltage. I did that and the aux leds worked. They are not MCU-controlled though and are always on unless the tail switch is turned off. The green switch leds are controlled and have the three options of Anduril and can also be turned off. The red switch leds did not work together with the green switch leds so I unsoldered and isolated that cable.

The pictures of the aux leds are located in the next post’s picture gallery as I took the photos later.

With the aux leds now working I would like to declare the Matainvoy ML18S FINISHED ON 02/25/2020. :student: :sunglasses:

I added some GITD tape underneath the optic and took lots of fotos. Here is a little picture gallery to show you those beautiful aux leds.

:heart_eyes:
What a light!!!

That must be awesome in person/hand!!!

Great work! I liked how you used the coins to have a good measure of the height needes for the copper rods :wink:

Here is a comparison of the Matainvoy ML18S, the Astrolux MF01S and the Convoy L6.

Some whitewall beamshots

Matainvoy ML18S

Astrolux MF01S, Matainvoy ML18S, Convoy L6

Astrolux MF01S, Matainvoy ML18S

Matainvoy ML18S, Convoy L6

And here are the outdoor beamshots. Whitebalance is 4500K, settings 3.2s F7.1 ISO400. The tree in the back is 150m away.

Control

Matainvoy ML18S, high and turbo

Astrolux MF01S

Convoy L6

My modded flashlight that I called Matainvoy ML18S has a new home as well, a big Maxtorch flashlight bag. It is the only bag that I ever managed to fit a L6 inside and it is definitely better than the generic white box.

That is one beautiful light! Great job with the copper spacer! Just wondering why connect the aux led direct to the battery? What is the issue with the original connection config?

Gorgeous Light ” Skylight ” Great build :+1:
Its hard to believe that was even possible to do. :sunglasses:
So much talent in this years competition, Wow :smiley:

Thank you, MascaratumB. Yes, it is an awesome flashlight if you hold the whole 1042g :smiley: in your hand and it lights up everything with a huge smooth hotspot. :sunglasses:

I needed something variable and thin and that was where the coins came to my mind. I’m glad I tried it before because if the copper spacer is not high enough the leds are not in the optic like they should be. First I wanted to cut 24mm but with the coins staples I found out that I actually needed 29-30mm.

Thank you, YogibearAl. That copper spacer was certainly not easy to build with only a hand saw and some filing.

In the first configuration the aux leds did not light up. The board is designed for 8.4V. Only the next version (v3.1) can be MCU-controlled and turned off if desired. This is the first version and the simpliest way to drive aux leds is to just connect them to the battery with the right resistors and parts on the board.

Well, at least I have an MCU-controlled lighted switch. After some experimenting you will leave the aux leds on one brightness anyway and if a flashlight has aux leds where is the fun in turning them off?

With some more electronic knowledge you could drive the board over a small FET like Lexel told me but that is too complicated to realize for me.

Thank you, CNCman. :slight_smile: Once you have that copper spacer the rest is not too difficult as the L6 is like it has been made for this MF01S optics and MCPCB.

I could have done also a simple mod but it always needs to be a bit challenging, right? You need to test your abilities and maybe try some new things.

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: