Build Log: Surefire A2 Aviator replacement LED ring [pic heavy]

calipsoii

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Update #1
(2011-03-24): These are now available for sale! Check out my sales thread for more details: http://www.candlepowerforums.com/vb/showthread.php?311596-FS-Homemade-Surefire-A2-Aviator-LED-rings


Introduction


This is going to be a long post, so how about I start with a little introduction? This is my very first post in Custom/Modified, and indeed, my very first flashlight modification. I'm a sysadmin by trade, which is a fancy way of saying I never took Electrical Engineering and I know almost nothing about the field. The reason I'm telling you this? Some of the things you're about to see will probably have you burying your face in your palm. Heck, some of the later pictures might have you chucking your cookies! Maybe finish eating before you continue reading. Go ahead, I'll wait.

Alright, let's continue.

I have a confession to make: I love my Surefire A2 Aviator. Well, it's more of a love-hate relationship, really. I love everything about the light except... the LED tint. :sick2:

See, I've got an A2-HA-WH and on low, white Nichia's just give me a serious case of the blues. Fact of the matter is, everyone I show the light to says:
Oh neat, so it's got a blue low mode and a white high mode?
:shakehead

Now everyone who owns an A2 is probably aware that there are/were 3 big projects intended to enhance this marvelous little light:

  1. FiveMega's Strion Socket
  2. Atomic Chicken's Aviatrix
  3. Koala's Onion Rings
Of those, only 1 and 3 are still available for purchase. I've already got my Strion kit (amazing little thing, I highly recommend it :thumbsup:) but I've been on Koalas waitlist for an Onion ring for 4-5 months now. When I woke up one morning with the brilliant idea to start this project, Koala had been MIA for a very long time. Exactly 1 day after I started the project, Koala reappeared and posted that he had completed his move and would be starting production any time now. :ohgeez:

Figures. Anyways, I was already knee deep in internet tutorials, so I figured I'd see it through. And without any further ado, I present my custom Aviator ring!

(Do I need a name for it? Everyone else has a name for their LED ring. Maybe the EHviator ring? Nah, that's cheesy.)

Project Plan

  • Objective: replace the stock Nichia white LED's in my A2-HA-WH with warm white ones that are approximately the same CCT as the incandescent bulb (~3300k) WITHOUT modding the existing LED ring
  • Deliverable: a drop-in LED ring that will fit the SF A2 allowing me to switch LED's without modifying the factory LED ring
  • Timeline: 5 weeknights and a Saturday
  • Budget: Ugh, I'd prefer not to talk about how much this cost. Knowledge and experience are priceless though, right?

Part 1: Planning

Meet our patient:
1surefirea2.jpg



For those who've never changed the bulb, this is what it looks like when you remove it:
2stockheadringin.jpg


For those who've never removed the LED ring, this is what it looks like. NOTE: the screws have a very small amount of thread locker on them. I found the best way to remove them was to use a tiny eyeglass screwdriver, press down hard, and use a series of very short, quick and aggressive twists. This was enough to break the adhesive, at which point they came out easily.
3stockheadringout.jpg


Anything that falls in the bezel is going to be a SERIOUS pain to remove. Protect the head of your light and keep the screws handy with a ZipLoc bag and an elastic band.
4protectfromdust.jpg


The stock LED ring. This is the last time you'll see such amazing soldering.
5stockring.jpg

6stockringortho.jpg


If you're new to electronics (or really rusty like I am), brush up on Ohm's law. You're going to need it to figure out what resistors to use. I mocked up my circuit on a breadboard and then tested it with a multimeter to confirm that the values were what I calculated.
7testcircuitoff.jpg


My warm/neutral LED's hadn't arrived yet, but blue LED's have the same forward voltage as white (white LED's are blue LED's with yellow phosphor added) so I ran 3 of them in the circuit.
8testcircuiton.jpg



The A2's not very forgiving in it's measurements. My method for getting screw-hole measurements was pretty archaic, but it worked well enough.
9pinsmeasureholes.jpg

10pinholes.jpg


With some measurements in-hand, I downloaded EAGLE and set to work creating a schematic. After 2 hours of frustration, I gave up on trying to make a curved trace and fired up Illustrator instead. Much better.

Part 2: Etching

The circuit diagram took way longer than expected. I won't bore you with the details, but by the time I was done, I felt like I needed a quart of Hagen Daas and a blankie.

Protip: Don't ever try to run a page from TIME Magazine through a laser printer's manual feed slot without first gluing/taping it to a regular sheet of printer paper. Don't ask.
11tonerpattern.jpg


Shiny!
12copperboard.jpg


You know the movies, where there's a montage and some music, and suddenly the protagonist is ripped and trained in Kung-Fu? That doesn't happen in real-life. Getting the pattern you're looking at took me SEVEN tries. That doesn't seem like a lot until you realize every single screw-up means you're out on the patio in Canadian winter (-10 Celcius), with a Zebralight H501W strapped to your forehead (it gets dark at 16:30), furiously scrubbing your piece of copper with Acetone strong enough to strip the paint off your car. Anyways, on the 7th try I finally got the hang of how long/hard to iron the pattern, resulting in some (mostly) crisp traces.
13tonertransferred.jpg


As with the toner transfer, I didn't snap any pictures of the actual etching process. I was too busy rocking a container of acid back and forth, hoping that the process completes before my feet freeze. Despite wearing chemical-resistant gloves and being extra careful not to spill, I woke up the following morning to find the cuticle on my left index finger covered in a white/green crust. The nail didn't fall off, thankfully.
14etchingcomplete.jpg


I could have jumped for joy when I held the board up to a light and saw that the traces on the back actually aligned with the front.
15theylinedup.jpg



Part 3: Drilling

I learned after the fact that when designing your circuit diagram, you want to leave a little empty hole in the middle of any pad you'll be drilling. This guides your drill bit and prevents it from skittering frantically across the surface until it finally bites into the copper 0.5mm off-target. Duly noted.

The DremelPress. It works pretty well actually!
17dremelpress.jpg


The screw holes lined up fairly well actually.
18holealignment.jpg


And they're the right size too.
19fitscrews.jpg


Little known fact: Canadians require Tim Hortons coffee every 24 hours or bad things happen. Think Gremlins.
20lunchtime.jpg


LED's fit ok too, this is starting to look good!
21fitleds.jpg


I won't lie, I was pretty darn proud of myself when I stepped back and looked at these.
22holesdrilled.jpg


Two words: dust mask. Buy a proper one and wear it. It won't save you from the horrible smell of burning PCB, but it might save your lungs.
23shapingup.jpg


Time for a little test-fit.
24screwholealignment.jpg


The screws complete the circuit back to the negative terminal of the battery. In the delivered Surefire LED ring, the PCB is bored such that the screws sit flush. Surefires also filled this bored area with some kind of conductive paint. Im using Nickel paint - it dries faster than anything I've ever seen. From wet to dry in 8 seconds. Work fast.
25nickelpaint.jpg



Part 4: Soldering

ATTENTION: Remember earlier when I told you I was a sysadmin and not an EE? Keep that in mind while viewing these pictures. I've soldered maybe a dozen times in my life and some of these components are damn small! By the third ring I figured out a method that worked for me and things went faster and smoother.

I went with 100ohm SMR's because:
a) they'd drive my warm white LED's at 33ma which is exactly what I wanted
b) Surefire uses 100ohm resistors on their red A2-HA-RD (which overdrives them a little, but I'm ok with that)
26smrsmounted.jpg


Trimming the LED's (5mm leads seemed to work ok)
27trimleds.jpg


Koala recommends that you trim the skirt on your LED's. He's right - they don't fit in the bezel properly with the skirt on. His method of a drill + metal file didn't work very well for me, so I ended up chopping the skirts off with the scissors on my LM Micra.
28ledstrimmed.jpg


Now things are really starting to look familiar.
29ledssoldered.jpg


The brass seemed really flexible when it was 12 inches long. When I trimmed it down to 9mm, it suddenly became really inflexible. After almost taking my finger off with the tin-snips trying to get a nice curve, I dropped the idea and went with straight contacts.
30springs.jpg


I'm not particularly proud of this soldering job, but I think with practice I'll get better. The brass is easily 10-20x as thick as the copper traces and it heats differently. Not only that, it retains heat, which means after removing the solder and the iron, the spring would simply slump against the PCB and THEN the solder would harden. Nothing worth doing was ever easy.
31springssoldered.jpg


Using what I learned from the first ring (which got deep red LED's) I did the second one (which got yellow-green LED's).
32secondring.jpg


PHEW, the end is in sight! Here we have the stock white ring, and my yellow/green and red rings. If you're wondering why I soldered 3 rings worth of resistors and only 2 of LED's, my warm whites are still in the mail. They should arrive this week.
33rings.jpg


Time for the moment of truth! Adding the Strion bulb:
34strionkitinserted.jpg


Took a week and a lot of patience, but there's nothing more satisfying than pushing that button and seeing your creation spring to life.
35redledworks.jpg

36greenyellowworks.jpg



Part 5: What's Next?

If you've stayed with me this long, I thank you! Hopefully my banter wasn't too annoying and the pictures were interesting. What's next for this project? Well, right now, my plans are to take a little break and relax. This project took 3 hours a night Mon-Fri plus 10 hours on Saturday to complete, so it's safe to say I'm pretty burned out at this point. I learned a lot doing it though, and most importantly, I enjoyed it!

With Koala returning to production on the Onion Rings, I don't know if I'll try to expand and refine my design. What I've made here doesn't hold a torch to his creation and it was never meant to. I just wanted warm white LED's without sacrificing the LED ring that came with my light. After I take a little breather (and after my LED's arrive) I'll probably work on finishing the remainder of the rings that were etched. I can't be the only one out there who dislikes the angry-blue Nichias.

Thanks for reading and happy modding! :)
 
Last edited:

calipsoii

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Update #1

My first batch of warm white LED's showed up and I had a chance to create a couple rings out of them. For reference, the two LED's are:

  1. SuperBrightLED's RL5-WW15030: 15000mcd, 4000k CCT, 30 deg.
  2. SuperBrightLED's RL5-7035: 7000mcd, 2940k CCT, 35 deg.
So without further ado, I'll let the pictures do the talking!

The LEDS

Stock Nichia cool white
stockfront.jpg


4000k warm white
4000kfront.jpg


2940k warm white
2940kfront.jpg



Beamshots

This isn't actually a white wall, it's concrete. The colors are a little bit exaggerated - there is less yellow in the 2940k and a little less green in the 4000k.

Stock Nichia cool white
stockbeamshot.jpg


4000k warm white
4000kbeamshot.jpg


2940k warm white
2940kbeamshot.jpg



Basement Beamshots

You'll have to excuse the mess - the basement needs a bit of tidying up. How about we just say it adds visual interest? :D The camera wobbles a little between shots, but you get the idea.

Stock Nichia cool white
stockbasement.jpg


4000k warm white
4000kbasement.jpg


2940k warm white
2940kbasement.jpg



Color Rendering

I wasn't expecting much in terms of CRI for these 5mm LED's, but the 2940k pleasantly surprised me with how bold it made colors stand out. I snapped a couple shots to illustrate what I mean.

Incandescent (control shot)
criincan.jpg


Stock Nichia cool white
cristock.jpg


4000k warm white
cri4000k.jpg


2940k warm white
cri2940k.jpg



Conclusions

My thoughts on the two LED's that arrived:

  • 4000k: I find this a bit too cold for 4000k. I have 4500k LED lights warmer than this. It lacks any blue (which is good) but the corona is a bit green. The LED reminds me of almost exactly of the stock Nichia's if you just stripped the angry blue out.
  • 2940k: This LED emits a pleasing, soft flood that is easy on the eyes. I do, however, find the light to be very yellow (so much so that I wondered at first if they shipped me a light yellow LED). While it really makes reds pop, it's hard to ignore the fact that it casts objects you know are white as a pallid yellow.
Overall, both are an improvement over the stock cool white Nichia's, but they're just not quite what I'm looking for. I have an order placed for a couple warm whites from a different company, so we'll see what they look like when they arrive.
 

calipsoii

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Update #2

I mentioned in the first update that I had a couple other warm white LED's on order from a different company. They've now arrived and I've had a chance to make some rings out of them. For reference, the two LED's are:

  1. LEDSupply L1-0-WW5TH15-1: 22000mcd, ~3400k, 15 deg.
  2. LEDSupply L1-0-WW5TH50-1: 4700mcd, ~3400k, 50 deg.
While the first LED (the 15 degree one) is rated at 22000mcd, it doesn't appear to even come close to that in output. Even when driven at 30mA, this LED is dimmer than the 4000k neutral white one I tested in Update #1, which is rated at 15,500mcd.

I spoke to a sales representative at LEDSupply about this and he confirmed that the 15 degree LED is the Nichia NSPL500DS. This is good and bad news:

  • The good: I've been trying to find a supplier of these LED's who will ship within North America for a long time
  • The bad: It doesn't appear to be outputting what the spec sheets say it's supposed to.
Upon closer examination of the datasheet for this emitter, 22000mcd is only typical from the highest bin (rank V). From there it goes down all the way to 11,000 (rank T). I would guess that the LED's I received are from one of the lower bins.

Enough chatter though, let's fire these babies up and see what they can do!

Color Rendering

Incan
booksincan.jpg


Stock Nichia cool white
booksstock.jpg


Nichia warm white
booksmodified.jpg


The results are amazing. The first time I fired this thing up, it caught me completely off guard - I've never seen a 5mm put out a beam like this. Colors are crisp and true, the beam is pleasing and not harsh on the eyes. When dropping down from incan into LED, the tint shift is almost unnoticeable - if I didn't know better I'd say that the incan bulb just went into Low mode. Pleased with the color rendering results, I snapped a few more pictures.

Ceiling Beamshots

These beamshots do a good job of pointing out the difference in output between these LED's and the stock ones. While the quality of the illumination is better, quantity suffers. Truth be told, I'm ok with it - if I wanted to light something up far away, I'd pop the incan on.

Incandescent
ceilingincan.jpg


Stock Nichia cool white
ceilingstock.jpg


Nichia warm white
ceilingmodified.jpg



MORE Ceiling Beamshots! :D

Incandescent
pipesincan.jpg


Stock Nichia cool white
pipesstock.jpg


Nichia warm white
pipesmodified.jpg



Cardboard Beamshots

While playing around, I noticed that the warm white Nichia's really shine when illuminating browns/reds.

Incandescent
boxesincan.jpg


Stock Nichia cool white
boxesstock.jpg


Nichia warm white
boxesmodified.jpg



Plant!

Finally, a couple shots of a little potted plant. Of all the pictures I took, these ones best illustrate the difference between the cool white and warm white LED's for me.

Incandescent
plantincan.jpg


Stock Nichia cool white
plantstock.jpg


Nichia warm white
plantmodified.jpg


Comparison .gif
plantanimation.gif



Conclusions

You've probably noticed that I only took beamshots of the 15 degree LED's. I did create a 50 degree ring as well, but wasn't happy with the result. I believe the 50 degree LED's are also Nichia's, but the tint just isn't as nice and the flood isn't as handy as you might think. It reminds me more of the yellow LED's I tested in Update #1.

As for the 15 degree LED's?

The only way I could be happier with the NSPL500DS Nichia's that arrived is if they were top bin. I've been happily EDC'ing my Aviator ever since I put these LED's in - they're just that good. All that's left now is to find a supplier who carries the top bin models and I'm all set.

Thanks for reading!
 

afraidofdark

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Amazing build thread, and wonderful play-by-play of your planning, testing, and photos of results :thumbsup::thumbsup::thumbsup:

Thanks for an excellent read!
 

calipsoii

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Amazing build thread, and wonderful play-by-play of your planning, testing, and photos of results :thumbsup::thumbsup::thumbsup:

Thanks for an excellent read!

Thanks for the kind words afraidofdark! I tried to make it the kind of build thread I enjoy reading myself, one with lots of pictures and technical details. Glad you enjoyed it!
 

calipsoii

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Update #3

There was some interest in the yellow/green LED ring I created in the original post, so I've decided to go ahead and create a couple more rings and take a few pictures. For reference, the Y/G LED's I'm using are:

  1. NTE30037 5mm water-clear Y/G: 2500mcd, 575nm, 12 deg.
I know there is a small group of diehard CPF'ers who love their yellow/green LED's, but I'll come out and admit that I don't understand the fascination. The beam is certainly an interesting swirl of colors, but output is incredibly low and color rendering is non-existent. That being said, there are very few lights in existence sporting Y/G LED's and they're not getting any less rare. Maybe getting a few of these rings out into circulation would be a good thing. :)


Beamshots

For anyone who's never tried to photograph the beam on a yellow/green LED (as I hadn't before tonight), my advice would be this: don't. I have no idea what goes on at the 575nm wavelength, but my digital camera REALLY didn't like it. Every single picture came out green until I discovered that setting the camera at the correct distance from the beam and doing a White Balance Evaluation produced a semi-accurate picture. Even after figuring out how to get a decent pic of the tint, I could NOT get the camera to focus on the beam - it simply wouldn't. After turning the overhead fluorescent back on with the new white balance, everything went bright purple. Definitely some strange things afoot here. :duh2:

Like I said, the beam is an interesting swirl of colors, mainly green with some brown
yellowgreen.jpg


It's also extremely dim, you really need night adjusted eyes before you can see anything with it. I did notice that it doesn't seem to blow your nightvision, however!
Left: Nichia warm white
Right: Yellow/Green
ygvsww.jpg


This was taken with the warm white Nichia's using standard exposure settings
booksww.jpg


I had to use the evaluative white balance trick and leave the shutter open for 13 whole seconds just to get this shot. Despite all that, the picture is quite accurate to what my eyes saw.
booksyg.jpg



Conclusion
Not a lot of pictures this time around, primarily because it's so hard to get a good shot of the light these LED's put out. I think these might be an acquired taste, because despite all the good things I've heard about the A2-HA-YG, I don't foresee myself packing an Aviator around with these babies in it anytime soon.

Until next time!
 

Machete God

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It appears that you've managed to match the tint of the LEDs exactly to the incan bulb, good job there!

I'm not an EE nor an experienced electronics hobbyist by far, but I laughed out loud when I saw the picture of your first attempt to solder the brass contacts and read the accompanying description of the spring falling down before the solder could harden! :D

Anyway, that was a great read, with plenty of well-taken and descriptive pictures to boot. Thanks for sharing!
 

calipsoii

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Update #4

I mentioned in my sales thread that I had several LED's on order, including deep red and UV. This evening I had a chance to create a ring with the UV LED's in it. For reference, these LED's are:

  1. Nichia NSPU510CS: 6800µW, 15 degree, 375nm
A note: these aren't cheap. They're over $3 PER emitter, so I was keeping my fingers crossed during ordering that they're good. Now that they're here, I can safely say: they're good.

warningg.gif
These emitters are no joke. I tried my absolute hardest to avoid observing both the emitted and reflected light. Despite that, it's 20 minutes after taking pictures and my eyes still ache. Due to the nature of UV light even though you only see a very dimly lit purple circle, it's actually extremely bright and your eyes are being damaged looking at it. These come with a very significant warning label and it's something to take seriously - you wouldn't stare into a tanning bed, don't stare into these.

Beamshots

Let's start with a shot down the business end:
uva2.jpg


To answer the question "How far do they throw?" the answer is "Pretty far". Long after you stop being able to see the visible light, objects are still fluorescing. The furnace in these pictures was about 5 feet away.
nonuvfurnace.jpg


uvfurnace.jpg


375nm is a good UV wavelength. It's perfect for curing Norland (something I intend to use this ring for) and it will display a lot of details that higher wavelength (read: cheaper) UV LED's won't.

Inova X5 UV
inovax5uv.jpg


Surefire A2 /w Nichia 375nm
a2uv.jpg


Conclusion
Overall, I'm quite happy with these LED's. They're a little bit specialized: perfect for curing Norland or checking the carpet for dog stains (at which they also excel) but not something I'd want to pack around in my Aviator every day.

Coming up next: 50 degree deep reds. I hope they're as good as I'm thinking they are.
 

sween1911

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This thread is absolutely amazing. Very impressed!!! I'm currently trading into an A2 and have been looking at what can be done to the it to ensure it's longevity in the long run. I have a habit of falling in love with trailing edge technology, and I want to make sure my A2 is still a viable light for awhile.

Thanks for sharing this labor of love with us! Looking forward to seeing what else you come up with!
 

CKOD

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Nice work! Any tests with the LEDs and norland any time soon? Ive been considering putting together a light with some UV LEDs for curing NOA, but I was unsure of the output requirements. I use a CFL black light currently for the final curing, but it'd be a lot easier to have a flashlight for tacking stuff in place initally. I was looking at a ledengin single die (5w input, ~150mW out iirc) LED but if these work, that may be vast overkill.
 

cm_mtb

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Your build thread is interesting to read, and your warm white ring looks great! When I finally have an A2, I'll be interested in one of your rings. :)
 

calipsoii

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Update #5

Well, I finally ran out of homemade PCB's, so it was time to make some more. After the pain of trying to align the front with the back (which didn't work all that well last time) I decided maybe it was time to try something new.

I learned Eagle.

It has a learning curve that's sort of like hitting a brick wall every night for a week straight. It's the only software program I've ever seen where the "Wire" tool doesn't draw wires, it draws lines. Software for engineers, by engineers.

Anyways, after poring over tutorials one Friday evening and sipping a few cold beverages, it finally clicked and I was on my way. The fruits of my labors:
a2circuit.png


Of course, it was only AFTER spending over a hundred dollars at a fab house that I realized they only etched on 0.062" board. :ohgeez: The A2 requires 0.03125". Anything thicker and the stock MA02 bulb defocuses (Fivemega's Strion kit is unaffected). Expensive mistake. Placed another order, this time on the right thickness PCB, so now I'm waiting on them to arrive.

What DID arrive is my box full of tiny electrical components (and I do mean tiny):
tinycomponents.jpg



Since I had some time this evening, I figured I'd sit down and test the voltage regulator. A voltage regulator (for anyone who doesn't know - as I didn't a few weeks ago) is a device that takes a range of input voltages and outputs a single constant voltage. The excess voltage is dumped either as heat or as current into the ground. This is important because the microprocessor you see above accepts 5.5V max, far less than the 8.4V max that rechargeables could dump through it. My weapon of choice:

  1. Microchip Technology's MCP1703T-5002E/CB: 2.7V - 16V input, 5V output, 250ma max current, 625mv dropout
I gave myself a bit of scare when I started to wonder what would happen when the batteries could no longer supply 5V. Would it flicker and die? Would I be limiting myself only to rechargeables? It was time to find out.

Soldering wires onto this thing is a serious pain
regulator.jpg


First test: whether it'll drop the nominal 7.4V off a pair of IMR16340's down to 5V
imrcharged.jpg


Looking good! Now, I grabbed a pair of "dead" SF123A primaries. Admittedly, they're not "dead-dead", they're just low enough that they set off the low-voltage warnings on all my lights so I can't use them. Their voltage under load is 4.8V, so less than the 5V output of my regulator. Moment of truth!
sfdrained.jpg


Success! While I couldn't find it in the datasheet, it would appear the regulator WILL output less than 5V, essentially dropping it out of regulation down into direct-drive. The forward voltage of the warm white LED is 3.2V which means if your power source can't supply that, it won't light. The closest thing I could find to 3.2V was a single IMR16340.
imrchargedsingle.jpg


Let's see if our regulator will pass that 3.9V through to the LED?
imrsingle.jpg


So there you have it! No need to sweat - when the CR123A's drop below 5V output, the LED's will continue to light. This little regulator will work juuuust fine.

Should be about 2 weeks until the PCB's show up, at which point I hope to have some more interesting pictures to upload.

Until then, cheers!
 

calipsoii

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Update #6

Hoo boy, this thread has been gathering dust now for a while, hasn't it? Time to brush the cobwebs off!

To quickly bring you up to speed: I've been making single-mode rings for a couple months now and have gotten quite good at it. In between batches of them, I've been working on a multi-mode version, powered by a microcontroller. These multi-mode rings are now at the point where they're ready to be beta-tested prior to going up for sale. There are just a few little things left to work out. ;)

The ATTiny13A datasheet recommends soldering the center pad of the microcontroller to the PCB to help anchor it. So far I've had very little luck. The pad is hidden away under the uC and I can't hit it with a soldering iron.
centerpad.jpg


Which leads us to the only logical conclusion. Why use a flyswapper when you can use a sledgehammer?
toasteroven.jpg


After applying a little solder to each of the pads on the PCB, I applied a little flux to the bottom of each of the components and stuck them in place. Some of the resistors are a little crooked but that's ok - the surface tension of the liquid solder should straighten them out.
componentsplaced.jpg


Bake at 230°C for no longer than 6 minutes!
bakeat230for6minutes.jpg


Well, that's what I thought, anyway. It turns out that the reflow profile for actual reflow solder doesn't apply to solder you've already applied by hand. The vast majority of the solder had liquified by 100°C but I was unsure if it needed more time and/or heat. Who was I to question a datasheet I found on the internet? I pressed on.

No, your eyes aren't deceiving you, that PCB is starting to brown at the edges. About 12 seconds later, it started to smoke and I frantically unplugged it.
nowthatshot.jpg


After letting the whole thing cool down for a bit, it was time to inspect the damage.
littletoasty.jpg


All told, it wasn't so bad! Some of the solder boiled and the flux charred, but the circuit still works just fine. Even better, the microcontroller's hidden center pad had firmly affixed itself to the board and all 10 pins neatly reflowed!
thatsnice.jpg


So what's next? Well, this charred little ring is currently being tested to make sure the firmware doesn't have any bugs. After that, I'll probably experiment with the time/temperature on the oven to see if I can hit the sweet spot where it neatly reflows but doesn't scorch.

Until next time!
 

calipsoii

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Update #7

While whipping up a batch of A2 rings this evening, I decided to photograph the process and document it here. A lot of photos perhaps, but hopefully it'll give you an idea of the process (and all the care and attention) that goes into making one of these. Enjoy!

----------------

To save a ton of money, I chose not to have the factory cut the PCB's into their familiar ring shape, so they delivered them in big sheets like this:
02circuitboards.jpg


The sheets are v-scored so that they easily snap into little 1" squares
03squares.jpg


I start by taking the edges off the squares with a set of tin snips
04tinsnips.jpg


It takes 16 cuts on each ring to knock off the excess PCB, leaving it looking pretty ragged
05roughcut.jpg

06scraps.jpg


Safety first for this next step!
07safetyfirst.jpg


Not only does it look bad, but these likely won't fit in the A2 head so they need smoothed down
08roughedges.jpg


You want to take precautions to avoid inhaling the dust that comes off them
09sanding.jpg


My trusty Zebralight H501W helps illuminate the excess that needs sanded off
10closeshave.jpg


Much better!
11betterj.jpg


A little rubbing alcohol removes any oils and dust
12cleanup.jpg

13allclean.jpg


Firing up my trusty Weller. Always wet your sponge!
14weller.jpg


After making hundreds of these little bridges, I'm getting pretty good at eyeballing the measurements. The metal comes from the excess I trim off each LED leg.
15bridge.jpg

16perfectfit.jpg


The SMD components come in little machine-feedable blister tapes - these are the voltage regulators
17smd.jpg


It's cheapest to buy 1000 resistors at a time. Needless to say, I have lots.
18resistors.jpg

19lotsofresistors.jpg


This is my pinky finger - this stuff is tiny! An illuminated magnifying glass does a good job preventing eyestrain though!
20pinkyfinger.jpg

21magnification.jpg


Time to attach the SMD stuff
22soldering.jpg

23solderingdone.jpg

24checkjoints.jpg


The LED's need a bit of work before they can be attached. These are ultraviolet ones.
25leds.jpg


Mark, trim and check the results
26marklegs.jpg

27checkresults.jpg


The skirts need trimmed off the LED's, so a few minutes with a Leatherman Micra fixes that little problem
28trimskirts.jpg


This might look low-tech, but after making enough of them, you get really good at mounting the LED's straight and true
31verticalled.jpg

32upanddown.jpg


A quick check to confirm it's all good...
33checkalign.jpg


... and it's onwards to finish the other two
35ledscomplete.jpg


The brass gets marked with a Sharpie so I know where to cut it with the tin snips:
37brassmarked.jpg

38brasscut.jpg


Using a pair of needlenose pliers and some regular pliers, the straight springs get bent into shape
39straightsprings.jpg

40bentsprings.jpg

41checkcurve.jpg


A quick check to make sure the curve profile is how I want it...
42checkprofile.jpg


... then they go under the iron to get tinned. This helps the brass heat up incredibly fast so that I don't scorch the PCB trying to attach them
43tinends.jpg


The first spring goes down and its joint gets checked
44solderspring.jpg

45checksolder.jpg

46checkheight.jpg


And now the other two!
47springsdown.jpg

48springsbottom.jpg


This ring is now officially complete, but it still needs tested. As mentioned, it's a UV ring, so these stylish shades come out!
49sunglasses.jpg


Everything is looking good!
50testresults.jpg


Now to mount it in my tester A2 and take it for a spin
51bulb.jpg


The camera photographs UV as a blue light for some reason
52all3.jpg

53glowing.jpg


Now a quick check that the incan beam profile looks right and isn't defocused or anything
54checkbeam.jpg


That's it! One UV single mode ring, good to go!
55complete.jpg


Thanks for reading along, hope you enjoyed the pictures!
 

milkyspit

Flashlight Enthusiast
Joined
Sep 21, 2002
Messages
4,909
Location
New Jersey
Very nice photo essay on creation of these little guys! I like some of the jigs you made for particular tasks. It's something I find myself doing quite a lot these days... and even an old(er) dog like me can learn some new tricks! Excellent. Simply excellent. Thanks for sharing!
:thumbsup:
 

Viper715

Enlightened
Joined
Feb 28, 2009
Messages
691
Location
Missouri
I love seeing your work. My eyes hurt just thinking about how small that stuff is and how hard to see to work with. Keep up the good work. Hope you still plan on programing for a three color multimode ring someday as that's my dream for this light.
 

brandocommando

Enlightened
Joined
Mar 10, 2011
Messages
437
Location
Oregon
Excellent! I will be ordering one of these very soon. I just need to figure what color combo I want.
Your videos and build logs are very cool indeed.
 
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