Skylight's 8th BLF OL contest entry, modified flashlight [DDH ML778SL FINISHED]

Thanks pinkpanda3310. :slight_smile: I chose a challenging mod on purpose because if it was not for the contest I would always postpone it. The contest gives me the right motivation to finish this mod within a certain time limit.

[quote=Skylight]

ā€¦and that time limit is coming aroundā€¦. :laughing:

Thanks for the reminder, pinkpanda3310. :innocent: Just realised that time is running fast and I need to reserve a few afternoons for flashlight modding.

Here is a little update what I have so far:

- Host Dongdonghai D8A

- 7x reflector

- 7 XHP70.2 leds (3Ɨ 3000K, 4Ɨ 5000K 90CRI)

- 20mm copper rod

- 65mm, 55mm, 40mm copper discs for the spacer

- 30mm TA driver and side switch

- 8 18650 tube

  • Soldering paste, thermal paste, 16 or 18AWG cable, drill, metal saw, dremel and other material

So as of now I have everything to continue with the internal parts of the build. Some copper sawing, drilling and soldering is left to do.

What I am still waiting for is a 82x2mm AR coated glass lens (from the Haikelite MT07). It showed me to have arrived in my country so it should make it in time. It will replace the 80x3.8mm stock not coated glass lens.

Today Iā€™m back with good news. Last week I managed to complete most of the remaining work so that Iā€™m close to the final assembly now.

Here comes what I have done step by step with many pictures.

I drilled the hole for the side switch with a 10mm drill to let the side switch fit in.

Result

Filed the edge of the 65mm copper plate to make it sit lower in the flashlight.

Before I continued modding I took some fotos of all the parts together.

I guess youā€™ll need a shoulder strap to carry it, after putting all that copper inside :smiley:
Keep it coming :wink:

:slight_smile: Nice collection of parts!

The three copper plates used for the copper spacer all need two holes to pass the cables through.

Before

A few fotos with leds and reflector installed.

During drilling

The holes in the 65mm top copper plate are determined by the position of the leds.

I marked the holes in the 55mm copper plate to overlap with the 65mm copper plate.

The holes in the base 40mm copper plate correspond to the holes from the driver cavity in the flashlight.

Finished

I just had to take some fotos in the decorative shiny copper swarf.

The last part missing for the copper spacer is a 30mm piece to be cut from a copper rod with 20mm diameter.

All the parts for the copper spacer are finished now.

Here is what the copper spacer will look like. The 40mm and 55mm copper plates will be soldered to the copper rod, the 65mm copper plate will be put in only with thermal paste.

The 82mm glass lens of the Haikelite MT07 arrived. The original glass lens of the DDH D8A is a 80mm glass lens which fits tightly inside the flashlight.

That is why I had to use the dremel to remove 2mm of the aluminium in the bezel. I didnā€™t touch the glass because it would be too risky to break it. Also, I donā€™t have any experience or tools for working with glass.

The inner part of the bezel has quite a bit of superflous aluminium that can be removed without structural damage, I suppose.

During work

After quite a bit of careful work the 82mm glass lens finally fits.

Nice purple AR coating on the glass lens.

Compared to the old glass lens

Being at it with the dremel I sanded the contact surfaces for the copper spacer in the flashlight.

Before

Finished

I add some measurement fotos of the glass lenses and the copper parts here to give you a better idea about the sizes.

After lots of mechanical work here comes the electrical part of the build.

This is the 30mm TA driver I will use. I will replace the 18AWG wires with 16AWG wires and the second gen. BSM Be Cu springs with third gen. ones.

I reflowed this driver last year. The soldering is a bit messy, I know. I didnā€™t have much experience with reflowing drivers back then. I already used this driver so it works.

Before I solder the cables on I will flash a new Anduril version on the driver because the version on it doesnā€™t work well. I can access the MCU better without cables.

The battery carrier for eight 18650 batteries I got together with the long battery tube needs some modification. I thought I had ordered a 2S version but apparently this is the 1S version because I measured 3.5V with all eight batteries inserted.

This is the battery carrier before the modification.

I bypassed all the springs with 2.5mm braided copper wire and made also some improvements to enhance the high current capabilities of the battery carrier.

I drilled holes through the two central PCBs and passed some short 18AWG wires through. This way, I connected the positive buttons on one side to the negative springs on the other side. I also removed the solder bridges that where made for the 3V configuration. I thought it would be easier to just connect the batteries in series instead of figuring out how to change the buttons and springs.

The outer four brass rods conduct the negative from the tail to the head while the central column is positive. I made bridges with 22AWG wire to decrease the resistance and make the battery carrier suitable for higher currents.

The battery carrier is a lot better now. I also had to heat the shrinking tubes around the brass rods because they were quite loose.

The battery carrier for the short tube has an integrated protection circuit that limits the current to 10A. I bypassed the springs on that carrier as well.

For the best performance I will use the flashlight with the 8x 18650 battery tube anyway.

Wow, this is coming together nicely. The copper is tough to work with, but it gets the job done.
Your work on the battery carriers is impressive as well. You are swimming in deep waters on this mod Skylight.
Not many modders have taken on a mod of this magnitude. Kudos for bravery :wink:

Nice stuff Skylight. :slight_smile:

Impressive :+1:

You are right. :sunglasses: The copper spacer weighs around 400g and the flashlight itself around 900g.

Thanks, MtnDon.

Many thanks, CNCman. I appreciate your kind words. :slight_smile: I tried my best and it worked nicely.

I will post more pictures and beamshots tomorrow.

Thank you, Agro.

Thanks, Rdubya18.

I just wanted to let everyone know that I have finished my modified flashlight today, 01/03/2021. :person_with_crown:

I will post the remaining pictures of the mod and the finished flashlight tomorrow.

Tonight I will take some beamshots. :sunglasses:

Good on you mate, :+1: , canā€™t wait to see!

Good work! Thatā€™s a lot of dremelling which must be difficult to get even! How does soldering large chunks of copper together work? Must need a large heat source eh?

Here are the last pictures of the modification process.

I soldered the led MCPCBs to the 65mm copper plate with 138Ā°C low temperature lead-free solder paste. The copper plate weighs 180g and should be perfect for getting the heat away from the leds fast. When direct driving the XHP70 leds I thought a 20mm star is relatively small and soldering is definitely better than thermal paste.

I connected the leds with 20AWG wires, negative on the outer ring. The plus wire will be soldered to a piece of braided copper, the minus on a pad of the central MCPCB.

I had to shorten the copper rod by another 4mm because it was too long and the bezel didnā€™t screw on any more.

This is how the copper spacer and reflector will be inserted into the flashlight.

I soldered three parts of the copper spacer together with 138Ā°C lead-free solder paste. I chose the low temperature solder paste so that I didnā€™t need to heat up the copper that much.

The finished part

The driver got a double BSM BeCu third generation spring bypassed twice. I bypassed the small inner spring with braided copper wire and soldered a 22AWG wire to the outside of the big spring. The seven XHP70 could draw up to 70 or 80A so I wanted to make sure the beefed up springs can handle this current without melting. I also soldered the 16AWG cables on the driver.

Before I assembled the flashlight I tested the leds and the driver to make sure there are no short circuits and the driver works properly.

Hurray, everything works as expected. :partying_face: It is great when leds and driver work at the first attempt.

So Iā€™m ready for the assembly of the flashlight. A last picture before I start.

A lot less parts then in the first full parts line-up.

Filed and cut a 1mm copper piece to fill the central gap where in the normal flashlight the MCPCB sits.

Assembly is mainly adding thermal paste and putting everything together.

The last thing to do is soldering on the main led cables and the switch.

I took a Sofirn Q8 switch and swapped out the leds and resistors. These are special RGB leds that have an integrated chip which makes them changing colors slowly and automatically. They are 0807 leds, a bit wider than normal switch leds but otherwise just the same. You canā€™t choose the red, green or blue colors separately like in other Anduril flashlights with RGB leds but when they switch through the colors they look very similar.

The switch leds are fully Anduril controlled. I achieved this by connecting a 47Ohm resistor to R1 and the aux led cable to the other end. I flashed the Anduril version from the ROT66G2 on the driver and it works perfectly.

Big thanks go to Scallywag who explained me how he made a lighted switch on his Astrolux MF02 mod. :beer:

Final function testing round

Switch leds work, main leds work. Awesome! :sunglasses:

As you can see in the pictures above I added some Glow In The Dark tape around the leds which can be seen later in the reflector.

I weighed the flashlight, short and long version, with and without batteries. Before the mod the short version weights 900g, the long version 1000g. The copper spacer should be around 400g.

At this point, I charged the eight LG HG2 cells I will be using in this flashlight, together with the two Golisi batteries of last years build to compare the two.

Wow fantastic! I looked through your post from this year and then through your post from last yearā€™s contest. Great stuff! I gotta get myself one of those hotplates.