How to do a one-mode AAA case mod/replacement with goal being ultra light weight

Yes that’s actually what I’ve been thinking! I got the copper one today, not going to destroy that one (it’s also heavy), but have an aluminum one coming in another day. Another idea is to cut away all but a couple thin rails of metal, just enough to hold the battery contact in place, and replace the missing material with light fabric.

This won’t be a light for daily use. It will be more just a lightweight part of a small kit… more as a backup than an everyday light.

Let’s see if I can do this image thing. Off topic of lights, but here’s the ultra-light string backpack:

Compared with the weight of some US coins:

Looks good. You can get something similar in outdoor shops here made of (I think) parachute material, also comes in a bag about the same size.

the singfire 348 does unscrew at the head, you can take the lens and the driver/led out and use in your bubble straw :slight_smile:

wle

Yes you should weigh one of them and see who wins ;-).

Nice. I have ordered one but it seems that the shipping will take a little while. Looking forward to it!

Well it arrived, earlier than expected, and I can’t figure out how to unscrew it at the head. Any tips?

Push the head on a rubber surface and twitst the body

I had a few that wouldn’t unscrew either.
I used pliers because nothing else worked.
Yes, it did leave some tiny marks…

By the way, since you’re in USA, maybe check out the Olight store on AliExpress (that unfortunately doesn’t ship to NL EU).
They recently had the i3S on sale.
The i3S has 3 brightness modes: low - high - moon.
It may be too heavy for your liking though, but it’s a sweet little light, has the best twisty switching i know of.
It weighs 0.43 oz (12.1 grams).

By coincidence I did recently order one (edit: based on what Jerommel said earlier)! Waiting for delivery. But in this case I didn’t care so much about weight, and got the heavy brass one (the coated one just because I’m unsure about whether the raw brass would have any lead which I’m not interested in absorbing into my skin).

Thanks for validating my purchase ;-).

“based on what Jerommel said earlier” well, duh, that would be you! :wink:

what you gain in weight you lose in ability to make it bright .
lights use the whole light /body and even your hand as a heatsink .
give and take what you gain you also lose .
give the g3 to grandma
the lithium is an easy way to lose weight .downside is just the price .

Time for a progress report…

Version 1 of the ultralight AAA flashlight is done!

Final weight for this version is 4.77 grams without the AAA battery. Not as low as my initial overly optimistic goal, but not bad. With the battery, the weight depends on the battery, but with an Energizer Ultimate Lithium for example, the weight is 12.5 grams total including the battery.

I’m pretty happy with this overall package weight.

What makes up most of the 4.77 grams? Well for one thing there is a solid metal bar spanning from the back to the front of the battery. This part is sourced from a cheap flashlight I got at a surplus place, and cut down. That cheap flashlight is unbranded and is a 2 AA light with four old-school LED bulbs… the metal strip was serving the same role in that light so I just took it out and snipped it in a couple places.

Then another heavy part is the pill, which seems to have significant metal mass to it, probably for heat dissipation. This comes from the SingFire 348 (thanks skinny_tie for suggesting the SingFire, and wle and Lexel for helpful tips!). Based on what I saw with the Olight i3e pill, the 348’s pill seems comparatively heavy; I will have to do a weight comparison on a scale.

But the i3e pill was too big for the straw. I could attach it on to the end of the straw with some heat shrink tape, but that seemed to complicate things and the SingFire 348 pill allowed a much more straightforward solution.

The SingFire head is tricky to open because you have to know that only the very edge (about 2mm or approx 1/8 inch) turns. So if you use a tool like pliers, they need to be applied to the very tip of the 348 flashlight.

The parts are: bubble tea / boba-type straw, battery, metal strip, pill, reflector, cover glass, and lanyard.

Everything pops into a straw, with the lens being glued in place on one end with Gorilla Glue, and the bent metal strip follows the battery into the package to provide some friction that holds the battery in place. A small tab at the back end of the straw holds the lanyard.

A couple of drawbacks: First, you need to hold the “button” (the metal strip) with constant finger or thumb pressure for as long as you want light. Second, I’m not sure this thing would pass a drop test. But for the weight, it seems pretty OK. I’m very happy with the weight of this version, and it also works well, stays together simply, is not very fiddly to use, and the battery is fairly easy to change. There’s also a small cosmetic flaw, with some extra glue mess around the edges of the lens… I’m going to see if I can do a better job on that next time.

BTW the weight listed includes the lanyard ;-).

Pictures soon…

Picture album link:

Ultralight AAA at imgur

(Below) Proof of light. A big THANK YOU to the posters on budgetlightforum.com who suggested ways to start on this project.

(All pictures shown here are below the captions, unlike on the image album linked above where the pictures go above the captions) So below is the weight in grams of all parts without battery.

Weight with battery. This type of battery is lighter than normal alkalines so ymmv. The electronics assembly, LED, reflector, and lens come from a $5 flashlight called a SingFire 348, which is very slim and can be opened at both ends. The straw is a boba (bubble) tea straw.

Front side view showing slightly messy glue job on lens.

Here’s what it looks like during assembly. The metal strip needs to be pushed down (in) to hold the battery in place. The curved nib nub will go past the lanyard and provide extra friction.

Closeup during assembly.

Another closeup during assembly. Assembly happens each time you need to change a battery, and is just a matter of putting the strip back in on top of the new battery, after you took it out to remove the old battery.

Assembled and ready for action, rear view. Note the curve in the metal strip is now pushed in past the lanyard. The metal strip is a cut down part from an old flashlight. To activate, put pressure on the metal strip with a thumb or finger.

Light in action:

As I said earlier, the goal was not to make something waterproof, or something blast resistant. Also it wasn’t a goal for it to be rugged, or something that will be a headlamp, or a main EDC flashlight. The goal is just to have a backup light that 1) is cheap 2) is ultra-light 3) uses AAA batteries 4) easy to store 5) simple to use (though limited… one mode, must press to turn on, etc.) 6) Could conceivabley be partially flattened and stored apart from its batteries in space-constrained situations where batteries can be obtained from a separate battery source such as a shared pool of AAA device batteries.

What would I like to improve? Well, making it stronger would be nice. The reliance on glue for holding the front together is downright embarrassing, heh. Also I’d like to get the size down further so it can fit in an Altoids smalls tin, which this one can’t. Having a true on/off would be great but isn’t really a goal. Drop resistance would be good but this is not there yet. Some things have to give… there are tradeoffs for being ultralight, but to me this is an interesting starting point.

Anybody have ideas for improvements? :slight_smile: I’m already thinking about how to make this lighter.

For storage, you might want to wrap a loop or two of the lanyard between the battery and “tailswitch” so that there is not accidental pressure causing activation, or have a plastic flap that must be flipped/rotated out of the way.

I think this is pretty cool!

That’s a good idea. With this pill it’s not much of an issue since it has a built in spring that pushes the metal strip away from the contact until the battery is pushed in slightly… but I might need that kind of solution for other pills.

Thanks! And thanks for the help and ideas.

Of course an Olight i3e is only about 3 grams heavier than this and for that 3 grams you get a lot… but this is partly just for fun, and partly to make a baseline I can try to improve on for future versions.

I find it inspiring.
I’m thinking now of a stainless steel thin walled tube, i have some from a ‘selfie stick’ that i disassembled.
And in stead of a brass pill i could use a driver with LED on it, like you find in the i3E and that little Convoy AAA light, and in stead of a reflector use a TIR optic.
Not sure how to do a tail cap though, but i think i could come up with something. :slight_smile: