Test Tube Lantern - My entry into the 2014 2nd Annual BLF Scratch Made Light Contest

Giveaways and Contests
1

Hi BLF, this is my build thread for my contest light. It is super basic and not worth winning anything, but I said I would do something so I will do it.

The inspiration:

I had gotten an unused XP-C based LED maglite module from OldLumens that was sitting around and not being used. I had found that LiFePO4 cells drove the module just about perfectly. My collection is also missing a compact lantern. I have plenty of diffusers that work, but they are almost as bulky as the light it attaches to itself in most cases.

The supplies:

I grabbed some disposable plastic test tubes from a neighboring lab’s trash previously to try as potential diffusers. They threw out some good stuff in their haste to move.

One thing I don’t like about putting a bare LED in plain view is that it is so intense it leaves spots in vision very easily. To avoid that, I thought I’d obstruct their view a bit with something that would diffuse/transmit the light. I settled on some GITD 6mm airsoft BB’s since they would also glow after use. This drops overall output, but that’s fine with me in this application.

Here are the main players, with some foil and a washer for electrical connectivity.

The build:

I filed down a bit of the cap so I could place the lip of my washer in place to contact the wall of the tube.

I then just shoved 8 BBs and the module up the tube with some foil lining a side of it.

Slide in the LiFePO4 14500 and pop on the cap, you can twist the cap to turn it on and off.

The results:

It works, absolutely no heat management, but the module didn’t have much anyway.

A few more action shots, and showing the glow.

Bonus Build: Test Tube Keyring Glow light

You may have noticed this in the earlier picture. Inspired by Lambda Lights Keylights, I tried to make a keyring glowlight with a smaller test tube I found. I chose a small 3mm yellow LED, put in a resistor, and added couple button cells. My conclusion, leave this to the professionals.

I potted the whole thing in some clear silicone.

I packed it together with a small magnet for contact and a cotton plug and it works.

Next to Thrunite T10 on moon mode, and illuminated by said moon mode. It is super dim.

Next to the Thrunite T10 and a 502B.

2

I like it. What a quick build. I wonder if there is something sinister going on with the use of some OL products?

I suppose we would all be disqualified though if that was the case. I believe we use a little inspiration from OL in all our builds.

3

Nice builds, thanks for sharing. Copper is sooooooo overrated, plastic is the future of flashlights!

About the keychainlght: I think that with the led so dim it will run for ages, you might have potted the batteries with the rest and just leave it on permanently.

4

Clever and very budget friendly.

5

very ingenious and budget oriented. :slight_smile:

6

thats the right spirit!

we are in the budget lightforum! :wink:

7

Love them both.

Small, Simplistic, cheap, yet genius.

I like over the top builds, but sometimes its nice to see something that is back to basics.

8

Is your middle name MacGuyver??? :bigsmile:

9

Thanks for the kind words :slight_smile: I would have loved to do something more elaborate if I had skills and time, but I am largely lacking both. I just wanted to make sure I did something before the contest was over.

10

Thanks for the build. That's pretty cool stuff. Easy to do, inexpensive and unique.

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IMHO, this is the best thing of scratch made builds, it just keep you surprised by the diversity and imagination you find on it.

original try HBomb

12

Nice build and didn’t cost much.

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I don’t think you lack imagination and skill just comes from practice.

14

Brilliant, including the GITD Airsoft pellets was genius.

15

There's a beauty in its simplicity and low cost, especially in a place like this.