This project was created specifically for the Instructables LED Contest. It is designed to use affordable components and tools available from Digi-Key and free software from Autodesk (specifically, Tinkercad). While I would recommend and am using a 3D printer (I'm using a Lulzbot Taz 6) it isn't absolutely required if you are otherwise handy with crafting with materials in other ways. This project doesn't require overly complicated or specialized equipment (no programming or complex electronics!) Most of all, this is creative and fun! I am making and giving these out as gifts this holiday season.

Step 1: Gather Materials

For my lanterns I am using:

Assorted LEDs (easiest if they are all the same voltage in the same lantern, say 2V or 3V, to eliminate the need for resisters... more on that later)
Soldering iron and solder
12V DC power supply. These are very common and cheap. Odds are you might have a few old 12V DC wall-warts buried in a closet you could use. (You could use other voltages, too, but I found 12V to be convenient.)
3D printer with a variety of filaments (I'm using a variety of colored PET and a wood filament)
Some wire. I'm salvaging some from some old phone/network cables.
Hot glue gun and glue, as needed.

Step 2: Lantern Design

This is the fun and creative part! For my lanterns I have 7 printed components with a possible third component for the LEDs (we'll get to that below). In the simplest form only two designs are needed: a side (x4) and a retainer (x2) for the top and bottom.

With a few test prints you can dial in the tolerances to have the retainers with enough tension to hold the four sides together firmly without the need for any glue. Add feet to the bottom retainer, print a decorative top, vary the materials/designs of the sides, etc. and there's endless possibilities. If you design the components at the same sizes, you can mix and match and experiment.

Step 3: LED Lighting

For the simplest design, wire up LEDs in series. With a 12V DC supply, divide 12 by the nominal drive voltage of your LEDs to find the number of LEDs to use. So, six 2V LEDs in series would work with a 12V supply. No resisters needed! Mind the polarity, of course. For more groups, just wire each group in parallel for as many LEDs are you want. A variety of designs could be used to put into the center cavity of the lamp. The designs shown here can slide diagonally inside and, again, with tight enough tolerances there can be enough tension to hold it securely without the need for glue.

Step 4: Conclusion

OK, OK, I know this is a pretty simple project, right? I look at the other Instructables and am impressed with the complex Arduino/computer/wireless/exotic/etc. projects. I purposely wanted to present something accessible and hopefully inspire some creativity with the use of LEDs and tools like Tinkercad to spark the imagination. With this project I found myself printing, assembling, disassembling, improving and building new components... mixing and matching. It provided me a platform to experiment with different designs, components, 3D printing techniques and materials. For example, I found LEDs with a built-in flicker function to emulate a candle. I also learned to 3D print directly onto clear plastic sheets to give nice crystal-clear windows. Battery operated lanterns, high-brightness LED arrays, even ideas for outdoor lights that could tap into existing 12V DC yard lighting. Start simple, introduce new ideas, and have fun! :')

I hope you enjoyed this and it inspired you to make your own LED-based project!