Working with “wireless” LEDs feels a bit like magic. These tiny LED assemblies can emit light without directly connecting to a power supply. The secret to their energy source is a nearby wire coil in which a high-frequency oscillating current generates a fluctuating magnetic field. Each induction-powered LED is attached to its own tiny wire coil, which responds to this changing magnetic field by producing a small (about 2mA) current.

A Little Light Self-Reflection

I often obsess over finding novel ways to use LEDs in projects, such as my weather displaying edge-lit rainbow (build it at here) and Twitter-connected LED matrix handbag. I had impulsively purchased a set of 10 wireless LEDs in mixed colors and a 5V transmitting coil, hoping to generate new project possibilities from this unique LED form factor. Disappointingly, an online search produced numerous articles on how to build your own induction-powered LEDs, but very few examples of ways to use them!

Any project using induction-powered LEDs will be subject to some constraints. Power transfer between the 5V transmitter and the LEDs drops off dramatically over distances larger than a few centimeters, so the coil must remain close to the LEDs. Also, inductive power transmission works best if the receiving and transmitting coils are oriented parallel to each other; this limits the ways in which the LEDs can move while remaining illuminated (see Lee Wilkins’ “Inductive Adornments” in Make: Volume 81, and “Skill Builder: Induction Instruction” and “Inductive Charging Bag,” both in Volume 41].

With these restrictions in mind, I wondered how wireless LEDs would look inside a kaleidoscope. The idea was compelling because a small number of colorful lights could create a large visual impact through repeated reflections in the kaleidoscope’s symmetrically placed mirrors. Induction-powered LEDs are particularly well suited for this use because they’re free to slide around when the kaleidoscope is moved, generating dynamic patterns with their shifting configurations. Encouraged by the possibilities, I designed and built this laser-cut kaleidoscope that uses wireless LEDs to generate colorful illuminated patterns. You can create your own version of the build from the instructions that follow.

Project Steps

Laser-Cut the Parts

The kaleidoscope’s parts are laser-cut from 1/8″ (3.2mm) sheet materials. The three different vector design files, available here, contain the outlines of the pieces to cut for the frame, the eyepiece covers and LED “collars,” and the mirrors. Cut the three rectangular mirrors from 1/8″ mirrored acrylic sheet, and cut the eyepieces and collars from 1/8″ transparent acrylic sheet.

The kaleidoscope frame may be cut from any 1/8″-thick wood or acrylic that has a nice finish on both sides. Kaleidoscopes are often displayed as art pieces, and an appealing construction material will result in a build with visual interest on the outside as well as on the inside. I used 1/8″ black acrylic for my frame, but many other materials can work as well.

When laser-cutting shapes from the design files, cut along all blue, black, and red lines. Any green letters or numbers are intended to differentiate similar looking pieces from each other and should be etched or scored on the surface of the piece (Figure A). After you’ve cut the parts, remove the protective paper from every piece except the three mirrors.

Figure A

Assemble the Frame and Eyepiece

Figure B

To start the assembly, gather the parts of the frame (Figure B). Select the six identical notched brace pieces and the three circular pieces without screw holes. Connect the three center notches in each brace piece to a notch in each of the three circles. After slotting each brace piece into all three rings, tape it in position with painters’ tape to prevent it slipping out. (Figure C). Be sure the brace pieces are seated as close to the outside edge of the circles as possible.

Figure C

After all six notched brace pieces are taped into place, select the circular pieces numbered 1, 2, and 3 as well as one of the clear acrylic triangles. These parts form the kaleidoscope’s eyepiece. Slide circle 1 just over the ends of the brace pieces so that each notch in the circle slots into the end notch of one brace piece (Figure D).

Figure D

Next, set the frame on its end, with circle 1 on top, and place circle 2 over circle 1, so that the top surface of circle 2 is flush with the very end of the six brace pieces. Slip the clear acrylic triangle into the triangular hole inside circle 2 (Figure E).

Figure E

Finally, lay circle 3 on top of circle 2, and secure all three circular pieces together with three of the 12mm M3 screws and nuts (Figure F).

Figure F

Prepare and Insert the Mirrors

Before inserting the mirrors, flip the frame over so that the eyepiece is at the bottom, and slide circular piece A over the free ends of the brace pieces so that each notch in circle A settles into a notch at the end of a brace piece (Figure G). Then set the partially assembled frame aside and gather the three rectangular mirror pieces.

Figure G

The matte side of the mirrored acrylic is a dull gray. Covering it with a prettily patterned adhesive vinyl gives the kaleidoscope a more polished appearance that you can customize to your taste. The vinyl I selected has a holographic silver sparkle pattern (Figure H). There are a wide variety of decorative adhesive vinyl options to choose at most craft stores. While applying the vinyl, leave the protective paper on the mirrors’ reflective surfaces until you’re done, to avoid accidentally smudging or scratching the mirrors.

Figure H

For each mirror, use scissors to cut a piece of vinyl large enough to slightly overhang all four edges of one of the mirrors. Take the piece of vinyl, remove the paper backing, and adhere it to the matte side of the mirrored acrylic, pressing out any bubbles with your fingertips or the edge of a plastic ruler. Then flip the mirror over so that the vinyl is on the bottom and run a sharp craft knife along all four mirror edges to slice off any excess vinyl (Figure I). Repeat this process for the other two mirrors.

Figure I

When you have trimmed all overhanging vinyl from the mirror, remove the paper from its reflective surface. Next, slide the mirror down into the triangular compartment inside the frame with its reflective surface facing inward. It’s easiest to insert the first mirror while holding the frame horizontally (Figure J), and then turn the frame vertically before sliding the last two mirrors into place (Figure K). If a mirror “catches” on the frame during this step, tug each of the long brace pieces toward the outside of the frame to create a bit more room inside the frame.

Figure J

Figure K

With the mirrors inserted, place circle B on top of circle A, and place the second clear acrylic triangle into the hole in circle B. Finally, lay circle C on top of circle B (Figure L) and insert the three long (16mm) M3 screws and nuts into the holes. Fasten the nuts loosely for now, as we’ll remove them later to add the LEDs and their container to the frame. Remove the painter’s tape from the frame and discard it.

Figure L

Take a Break to Enjoy the View

Before incorporating the wireless LEDs, now is a good time to pause and reflect (pun intended) on what you’ve created. You have built a working kaleidoscope! Place your eye at the eyepiece and point the other end at any colorful object to see unexpected patterns emerge. Even simple images like Makey (Figure M) acquire new dimensions inside a kaleidoscope.

Figure M

Prepare the Induction Coil and Holder

In this step, we’ll set up the electronics to power the LEDs. The induction coil and current driving circuitry are fragile, so we’ll create a protective case for them using the laser-cut parts shown in Figure N. We’ll use the same holographic vinyl that covers the mirrors to secure the transmitting coil to its case.

Figure N

First, trace the outline of the induction coil case onto the vinyl’s paper backing and cut the resulting shape from the vinyl — cutting along a line that is about 5mm inside the outline you traced. The vinyl should cover most of the bottom layer of the case without blocking the holes.

Figure O

Lay the vinyl on a flat surface with the protective paper facing upwards, and peel off the backing. Carefully stick the transmitting coil onto the vinyl, centered as well as possible (Figure O). Now turn the vinyl and coil over together and adhere them to the bottom layer of the transmitting coil case (Figure P). Trim away any vinyl that covers the current driving PCB or the screw holes in the case. Place the next case layer, which has the open slot in its handle, on top of the vinyl, then place the final, solid-handled layer on top of that one. Secure the three case layers together with five M3×12mm screws and nuts. The transmitting coil’s power wires will extend from the end of the case’s handle (Figure Q).


Figure P
Figure Q

When the case is completed, strip the ends of the red and black power wires if necessary and screw them into the corresponding +/– terminals in the screw-terminal-block-to-barrel-jack adapter. Check carefully to be sure the wiring polarity is correct. Then insert the barrel-jack-to-USB cable into the adapter.

Now attach the USB cable to any 5V regulated power source. Test the transmitter by placing a few wireless LEDs in the center of the coil to be sure they light up. Figure R shows that the LEDs facing upwards, with coils parallel to the transmitter, light up, but the LEDs whose coils are perpendicular to the transmitter may light up only slightly or not at all.

Figure R

Once you’re certain the electronics work properly, unplug the USB cable from the power source and set the transmitting coil to one side while you attach the LED compartment to the kaleidoscope in the next step.

Assemble the LED Compartment

The powered LEDs will shine brightest when facing directly upward into the kaleidoscope, so we’ll place them inside tiny clear acrylic “collars” that maintain their orientation as they slide around (Figure S). Be sure that you’ve removed any protective paper from the acrylic rings before carefully slipping the LEDs into them. The LEDs should slide easily into the rings. Do not apply pressure to force them in. If the rings seem too small for your LEDs, laser cut another set of rings with a slightly larger inner hole. The LEDs and their collars are easily misplaced, so put them in a small container and set them aside for the moment.

Figure S

To attach the LED compartment, set the kaleidoscope vertically onto its eyepiece with circle C visible on top. Remove the three M3 screws that hold layers A, B, and C together. Carefully put an acrylic collar around each LED, then place each assembly on top of the clear acrylic triangle with its LED facing downward into the kaleidoscope (Figure T). Once all the LEDs have been placed, stack circle D on top of circle C so that the LEDs sit inside the triangular holes in both layers C and D. Next, place circle E on top of D, lining up the screw holes in all five lettered layers. Reinsert the M3 screws into their holes so the screw heads rest on top of layer E. Secure the screws underneath layer A with the M3 nuts. Now, when you move the kaleidoscope, the LEDs are free to slide around, but their collars keep the LEDs always pointed toward the viewer.

Figure T

Your wireless LED kaleidoscope is now complete!


Go With the Glow

To use your shiny new kaleidoscope:

    • Power the transmitter by plugging the USB cable into a 5V source.

    • Set the end of the kaleidoscope with the LED compartment into the transmitter case to generate power for the LEDs.

    • Look through the eyepiece to see the symmetric shapes created by the infinite reflections of colorful LEDs!

To create new visual patterns, tilt and rotate the kaleidoscope within the transmitter base to move the LEDs around.


To take this project a step further, you might try adding reflective beads or rhinestones into the container along with the LEDs. Choose objects that won’t catch on the small acrylic rings. Or try laser-cutting new collars of different shapes and colors to place around the LEDs. Or make the project portable with a small 5V phone power bank.


You can easily change the appearance of this build by cutting the frame from an alternative sheet material and selecting a different color of adhesive vinyl. Below shows a kaleidoscope I created with a clear acrylic frame and a striped holographic vinyl backing on the mirrors.

The build instructions in this article will work for any choice of 1/8″-thick opaque sheet material, however they require small modifications if you select a transparent acrylic for the frame. Modified instructions and adapted design files for a clear frame are found in a sub-folder called TransparentFrameDirections, so be sure to read them before you laser cut your materials.

Regardless of what materials you choose, the very best part of creating your own wireless LED kaleidoscope will be showing it off to others and watching their eyes light up when you do.