calipsoii
Flashlight Enthusiast
- Joined
- Apr 21, 2010
- Messages
- 1,412
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:
:shakeheadOh neat, so it's got a blue low mode and a white high mode?
Now everyone who owns an A2 is probably aware that there are/were 3 big projects intended to enhance this marvelous little light:
- FiveMega's Strion Socket
- Atomic Chicken's Aviatrix
- Koala's Onion Rings
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:
For those who've never changed the bulb, this is what it looks like when you remove it:
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.
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.
The stock LED ring. This is the last time you'll see such amazing soldering.
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.
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.
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.
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.
Shiny!
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.
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.
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.
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!
The screw holes lined up fairly well actually.
And they're the right size too.
Little known fact: Canadians require Tim Hortons coffee every 24 hours or bad things happen. Think Gremlins.
LED's fit ok too, this is starting to look good!
I won't lie, I was pretty darn proud of myself when I stepped back and looked at these.
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.
Time for a little test-fit.
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.
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)
Trimming the LED's (5mm leads seemed to work ok)
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.
Now things are really starting to look familiar.
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.
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.
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).
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.
Time for the moment of truth! Adding the Strion bulb:
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.
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!
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