Uncle flashlight (build thread)

Flashlight Modding and DIY Parts
1

Hi All,
This is going to be a different sort of build thread as I’m actually only doing it for one fella. My uncle recently asked me to build a brightish, high CRI, side switch flashlight for “light painting”. Near as I understand it this is a photography technique involving dark and light. Point is, I recently got him to buy his first set of eneloops and now I get to build him a real flashlight. Many of the techniques here is old news to many members here but the old uncle is a complete muggle, so enjoy the pictures I took using dark and light.

Short version is that we’re stuffing four Nichia 219 90+ CRI emitters into a blue 2D mag and driving them to 3+ amps each with 8 eneloops in 4S2P electrical configuration. We start by tearing down the maglite.

Then we tear apart the switch.

Then we throw away this sh… stuff, cause it’s useless.

Let’s focus on the switch and driver for an hour or two. Start by cutting that plastic tube off the switch.

Cut the tab off the end of the negative path/switch anchor, solder an 18 gauge wire to it and put it back where it goes.

Now we’re working on the driver but still working on the switch. We’re going to solder all those little parts to the circuit board designed by a member of this very forum.

But first we need to program that little spidery looking chip for one mode operation. Yes I could just use direct drive but I’m expecting over 12 amps to the emitters and the driver allows me to route power around the switch mechanism. First step is to pinch the chip in the blue cloths line thing.

The blue cloths line thing is connected to a complicated looking thing that connects the chip to a laptop in a process known as “magic”.

This is “C” coding of a firmware known as “STAR”, also developed by a forum member. I’ve tweaked a few things and removed all modes but “high”.

The program spits out a “hex” file which we save to an appropriate location on the laptop.

Here we see a bit of code which loads the hex file onto the little spidery chip. We can also see a lumpy creeper with a camera.

Done! Avrdude is always so polite despite all the names I’ve called him in the past.

Next, we solder the chip onto the driver and give it a test.

Now we solder a wire from the positive of the driver to the positive of the switch. Coil the wire and glue the driver to the switch.

Now we drill a hole through the switch body and run an 18 gauge wire to carry the main current to the emitters.

The switch/driver is ready to install!

Onto the head of the light.

First we make a heatsink out of 1.875” aluminum rod, the major stages are in the pic below.

Here are the emitters on noctigon and the centering rings to be used.

There isn’t enough room in the head to fit everything in so we need to measure how tall the new innards will be.

Then comes mathing and puppies.

Having a reasonable depth, we proceed to the basement to ream out the head with the dremel and metal cutting bit.

With the head a bit deeper, we can epoxy the emitters to the heatsink and wire them electrically in parallel.

Once we wire the emitters to the switch we can install the whole thing into the light and then install the reflectors, lens, and bezel.

To be continued in the next post…

2

So we’ve got the light engine/head put together but we’ve also got to deal with making a battery holder and deal with the fact that the battery holder I build won’t fit into the flashlight. Battery holder first.

We start by modifying a printed circuit board(created by yet another member) originally meant for 4 batteries in series. A little solder, high current springs, and a some copper strips completes the circuit board mods.

We then need to cut brass 5/32” brass tubing to the correct length (a bit more than four inches).

We’ll need three tubes, a length of 12 awg solid copper wire, six rivets, and a wee brass button to nearly complete the holder.

The rivets won’t fit in the provided holes so we need to ream them out to ~1/8”.

We need a non-conductive center post so I sacrificed and old plastic cloths hanger and epoxied it in.

While I had the JB weld out I also covered the solder joints from soldering in the awg 12 wire used to return the positive contact to the top of the holder.

As mentioned above, the holder is just about a millimeter too wide to fit into the barrel of a stock maglite. So lets make it non-stock!

I used a method Old Lumens pioneered a number of years ago to quad bore a D size maglite tube. The method involves reaming the inner diameter of the tube with a 35mm bi-metal hole saw. I’ve been through a half dozen mags with this unit and it shows no sign of dulling.

Simply chuck the hole saw into father in law’s drill press, lube with WD-40, and ream it out.

The required depth is greater than the hole saw can reach on it’s own so I used a 1/4” socket extension and a 3/8” socket to extend the reach a bit.

As you can see the hole saw leaves the tube wider but also a bit ragged. I chucked up a screwdriver and wrapped the handle with 100 grit sandpaper followed by 180 grit to smooth the interrior of the tube.

Now that the work is done we have just enough room for pics of the finished light.

It ended up drawing around 13.5 amps off slightly used eneloops so I expect it might peak at a bit over 14 amps on fresh cells. Max output is likely around 2200 lumens. There is enough heat from the head of this light so it could double as a hand warmer on those cold Florida summer nights.

3

WOW

a good build thread!

thanks for sharing :slight_smile:

4

Great in three ways
1 the writing
2 the build
3 the result
Thanks

5

Nice and complete. I like it.

6

Very nice. Thank you.

7

LOL! Muggles build thread for a Muggle’s flashlight build! I like it! :crown:

8

you forgot to post the order list…

9

Another nice MAG build :beer:

10

Excellent .
Thanks for sharing .

11

Thanks for the detailed build! :+1:

12

Great build, nice attention to the details.

13

Really well put together thread that gives some insight into how you work your magic kyhfishguy. Thank you for sharing. :slight_smile:

14

Nicely done! Great to see what can be accomplished without fancy tools. Are those Convoy S2/S6 reflectors?

15

Orsm build. thanks for posting it up. The last update to come will be interesting. :stuck_out_tongue:

16

Thanks for the effort posting this here. These days we need more of this goodness. I like how you used the copper between the stars and showed how you programmed the mcu. Excellent post.

17

Excellent Work and Awesome Writeup!

Reminds me of Nereus (sp?) from CPF, he was always fond of multi-emitter Mags and did excellent work in regards to both quality and presentation.

Kudos!!!

18

Great work.

19

Nice build. That looks like a lot of work. Is 2s4p Eneloop a typo? That would be feeding ~2.6 volts to the emitters which would barely light them up.

I found it strange that you posted detailed photos of the technical aspects but wrote the text satirically at a childs level of comprehension. Why did you do that? Also thought it strange to give anonymous credits several times in the form of “a member of this forum” rather than just stating their screen names.

Glad to see a detailed mag mod. Show ’em how it’s done.

20

Yes, the 2S4P was a typo. Now corrected to 4S2P, thanks. The reason for the non-technical language is that I wrote this thread for (to) my uncle who knows nearly nothing about the interior of high tech flashlights. This was also the reason I gave credit to anonymous forum members instead of directly crediting. My uncle has no reference for who JohnnyC, Helios, and Wight are or what they’ve done for the BLF community. To be honest, I wouldn’t have bothered with a build thread for this one as it’s nothing I haven’t posted before but uncle wanted details. I promise the next one will be back to my old technical and dry style.

PS Credit to Hoop for the driver flashing tutorial visible in one of the laptop screen shots.