Introduction: Light-Up Shamrock St. Patricks Day Coaster

About: I used to teach middle school science, but now I run my own online educational science website. I spend my days designing new projects for students and Makers to put together.

Make a St. Patricks Day Coaster that lights up your drink when you place a glass mug on it!

This project uses LEGOs and Crazy Circuits components to create a fun drink coaster. Due to the modular nature of this project it's simple to use this basic setup for other holidays or themes.


You will need:

Step 1: Build Your LEGO Base

Build up 2 plate layers of Legos, 12 studs across and 12 down - except a square section at the bottom as shown. This will create a space for your battery component.

Then, line the square with a border of 1 stud wide plates, leaving a gap near the bottom battery square as well.

Add two studs at the top fo the battery square as shown. (Pictured in grey)

Step 2: Add Maker Tape

Use the photo as a map and add the Maker Tape as shown. Look carefully - near the battery square, there are a few places that the tape "jumps" up or down a level.

Step 3: Add Crazy Circuits Components

Add the Crazy Circuits components as shown. Be sure that the negative side of the two LEDs is facing up on the top two, and down on the bottom two.

Step 4: Cut or Print the File

Download the cut files or Print files. Cut the shamrock file out of green adhesive vinyl. Cut the square file from white cardstock. If using the Print files, print on white paper. Use a craft knife to cut out the shape on the grey lines, and cut out the yellow rectangles.

Step 5: Assemble the Design

If you used the print files, skip to the next step.

Peel/weed away the negative space in the design. Use some contact paper on top of the design to keep the shamrock in the right place. Then, peel the backing off the vinyl. Place the piece of white card stock in the center of the square as shown, on the adhesive side.

Step 6: Wrap the Coaster

Place the LEGO structure in the center of the square and wrap the design around the coaster, wapping the square flaps first, then the ones with the tapered edge.

If you used the printed design, wrap the structure in the paper, and use tape to adhere it underneath the coaster.

Step 7: Use Your Coaster!

Turn the coaster over, grab a clear glass or mug, and illuminate it!

Changing the vinyl cover, LED color, and LEGO colors you can easily create different designs and patterns. Maybe mark a blue Tardis coaster, or a festive Halloween pumpkin coaster! The possibilities are endless!