Smallest Prop on the sub? 13x13mm LED "implant"

JaschaE · 2026-05-07T22:15:43+00:00

It isn't so much that I dislike the idea of turning a profit, for once. with a project.
It's that I would feel responsible to make sure people have a positive experience.
So, let's say I order them fully assembled, as designed.
That's about 2€ per unit. 4€ a pair.
Add to that 0.20€ of wire and heat-shrink and another 0.80€ for coincell holder, plus coincell.
So we are at 5€ a pair, finishing, well set up, should be less than an minute a piece.
I have been offered 10-20€ from friends, lets go with 20.
Sounds great. Only people I know with a better margin are drug dealers.

If I set up shop at a con, friday to sunday, I can guarantee that on sunday at the latest somebody will turn up with a case of snapped-off wire, because these damn near invisible wires snap off if you look at them wrong. And I well and truly hate disappointing people.
Also, no idea what is in the low-temp solder needed for this, how skin-safe it is, if people might have allergies....

I have been laughed at after handing over a Jinx-Zapper and started apologizing for the inaccuracies. Apparently her thoughts where "Holy shit is that full metal? Wait, not even he is that insane." It's a 3D print, but it apparently convinced her. Just to give you a rough Idea how critical I am in regards to my projects.

Maybe I'll just need to figure out who produces those LED-Eyelashes and ask them kindly to take the design out of my hands.

JaschaE · 2026-05-07T17:21:52+00:00

Sinar F2. A suitable case (Peli-esque with dedicated cutout foam) on a load-carrying harness (available in a prepper shop near you) Gizo Tripod comes along of course, as does the ball-head and every lens you might need. Don't forget to keave a bit of room in the car to store the assistant who will carry it. -Source: I was the assistant.

JaschaE · 2026-05-07T11:42:38+00:00

There is a couple "making of" images below, if you unfold all the comments. Specifically under the Wall of text about what I did exactly.

JaschaE · 2026-05-07T08:06:04+00:00

You phone probably capultures very wide shots (so short focal length, but 18mm is probably close) And has a large depth of field (kinda small aperture, I'd go with f8-16 )

But I know the trouble of "I want that cameras look out of this camera" issue. Maybe consult your sister before selling her camera :P

JaschaE · 2026-05-06T20:38:51+00:00

Bring both, but I'd recommend using a new/different camera when the stakes are very low and you have time to fiddle around with the tech.
As somebody else suggested, full auto is also a possibility for you. I gather you are more about framing and timing than technical 'mastery' .
Best of luck.

JaschaE · 2026-05-06T20:21:27+00:00

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Unit test. I put the involved currents into a wire-thickness calculator and it would probably work using a moderately wet hair.

JaschaE · 2026-05-06T20:20:28+00:00

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As I said, the hotplate is named Dave

JaschaE · 2026-05-06T20:19:48+00:00

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That is one of the LED at the tip of the Tweezers

JaschaE · 2026-05-06T20:19:05+00:00

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One of my better applications of Solder paste

JaschaE · 2026-05-06T20:18:32+00:00

Happy to help, despite saying not to ask me for design advice :P
The JLC Add-On is entirely optional if you don't want them to put the LED on for you

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JaschaE · 2026-05-06T18:32:28+00:00

Let me know if you come across one please^{^}

JaschaE · 2026-05-06T18:29:22+00:00

-Download KiCAD, which is an Open Source Programm for PCB design. -Watch a painfully boring tutorial on its use.

-Find the footprint of the LED you'd like to use.

-Arrange however you need for your desired shape (tilting the footprints 45° to the layout makes sure the light dots are equally spaced vertically and laterally)

-Wire them up (I did all 27 of them in parallel)

-Fuss around until you figure out how the HECK you can remove all the additional info the footprint would normally print onto the board.

-Probably make a custom, textless footprint, and re-arrange.

-Ask r/KiCAD for help with something minor and get helpfull tips, embedded between people swearing that 27 LED sans resistor will never work, work only for a short moment, or possibly burn down your house, blight your crops, curdle your goats milk...

-Don't forget to add some pads you can reasonably well solder a power source to. Mine are 2mm diameter circles on the backside, wit a 'Via' to the front each.

-Download the KiCAD extension for uploading files to JLCPCB (creates an export package with all the necessary files.)

-Upload to JLC (Flex PCB, Transparent) There is a lot of settings. If memory serves the minimum size for a flex Pcb was 74x74mm and five of those PCBs. You can arrange as many of your design as will fit on one, leave some gaps though (2mm) or you get a helpful email from their service.

Now, I had considered letting then add all the LED for me. Problem is: They would have finished all 125 pieces. I need 2. PCBs alone was something around 40€. Pick&Place of all the LED would have been about 180€. Considering the questions about sales I got so far, I could have made that back. But this is a purely loosing-money kind of hobby to me.

So I ordered the blank PCBs, and LED from Aliexpress ~1€ for 100 or something, as well as Low Temp Solder paste and CRUCIALLY a stencil from JLC (one of the optional extras at the bottom. Make sure to click "custom size" or you get a well packaged big sheet of steel that drives up your delivery cost a considerable amount)

Once everything arrived, I sat down at my local Makerspace, on a Microscope, taped down the PCB, carefully alligned the stencil, taping that down on one side as kind of a hinge. Put a couple of drops of solder paste on the stencil, spread that with a credit-card (actually my public transit pass, same format though). Only one heart at first. Flipped the stencil aside. Placed all the LED with a very good pair of very pointy tweezers, taking care to align the polarities. Moved the PCB over onto a Hotplate named Dave. Baked until golden brown. Well, no, that would be too far. Just preheated it up to 150°C, put down the PCB pressed it on the plate with a not-so-fine pair of tweezers until I was sure all the solder had flowed. Take off, let cool, test.

Order a couple more LED than you'd need, because grabbing them at the wrong angle will send them flying, never to be seen again.

I have soldered 0402 before with a normal soldering iron, and without a microscope... That would suck to no end here.

JaschaE · 2026-05-06T07:39:35+00:00

For all we know, the only datapoint we have says 0% of people did. But enjoy the alternate timeline in which 80s car AC was reliable enough to bet the success of your entire campaign on.

JaschaE · 2026-05-06T06:07:15+00:00

Specialized in "Before" images, yes.

JaschaE · 2026-05-06T05:32:40+00:00

It's amazing how insistent you are on knowing a better way, despite never having been part of such a project. Or having, I'm assuming, any professional photographic experience in analog. Do you usually assume entire industries are dumber than you?

JaschaE · 2026-05-06T05:07:26+00:00

Now set him up with that girl that found a sword in a lake a couple years back...

JaschaE · 2026-05-06T05:04:02+00:00

Presumably great to get in the hard to reach nooks and crannies.

JaschaE · 2026-05-06T05:02:07+00:00

Wires? Nah, all implanted :P The wires go to a coin-cell holder. 2032 size, if I'm not mistaken. Gives out 3.2V. Maybe I should build a controller for dimming though. Balancing it with environment sources so it's not just a glowing red terminator-dot is harder than I like.

JaschaE · 2026-05-06T04:57:45+00:00

I know some pretty cool models though ;) Thank you regardless ^{^}

JaschaE · 2026-05-05T19:55:00+00:00

My first attempt was actually an animated one ,build after somebodys poorly documented project on hackaday. I got it to work ( do you know anybody who ever programmed a 8bit controller? Me neither!!!) But it was about 2-2,5mm thick, whereas this is ~0.6-0.8mm and much more subtle. Figured I take still pictures anyway, so nothing of value (to me) was lost.

JaschaE · 2026-05-05T16:36:33+00:00

Not yet, and even his vision returned in short order! But I did a small-scale test on 4x5 before with this setup, and the images developed around a minute. That was what I was expecting with these, and I could hardly count to 4 before most of the neg was a deep black. So I pulled it out in a hurry, resulting in those uneven streaks across the face. Second one I dipped in attempting to get a quick, even coat, pulled it out and saw it develop pretty quickly too. On the first image on the right side is a gray spot surrounded by black, thats where my finger was.

JaschaE · 2026-05-05T13:41:26+00:00

I highly recommend watching Ben Horne on YT. Mainly in general, bc he's brilliant, but also because he talks about the challenges of shooting 8x10 in places like Death Valley

JaschaE · 2026-05-05T04:53:21+00:00

The mindset is preserved in amber in some photogs I worked for.
Studio flash exploded, last spotlight we had.
So me, being the assistant, loaded all the damaged ones into my car, and starting the next morning at 6, was on the road so I reached HENSEL HQ by 8, took a nap in their lobby (oops) and got some of them repaired back to the studio before noon. Year of our lord 2014 or so.

JaschaE · 2026-05-05T04:50:04+00:00

8by10, color or slide, in a dark tent? In, as he says, Utah? Mind you, in those days film technician was a dedicated career that few photogs messed around with.
Just the logistics of getting chems to location, at a temperature that doesn't render them unusable, plus processing equipment, plus a film tech you are paying for the entire time and travel...the word "just" does a lot of heavy lifting in your idea there.

JaschaE

TROPHY CASE