This is a pretty challenging little puzzle that is relatively easy to make.
There are three puzzles to be solved.
- Puzzle 1 - Arrange the cubes inside the enclosure so there are 4 different colors in each side.
- Puzzle 2 - Pull the cubes out the enclosure and form a 2x2 square out of the cubes. For this puzzle, you must have 4 different colors on the top and bottom, and 2 different colors in each side.
- Puzzle 3 - Again, this one is outside of the enclosure and makes a 2x2 grid. For this puzzle, you must have 4 different colors on the top and bottom, and same color on each side.
Per Wikipedia, the puzzle was created by Frank Armbruster and published by Parker Brothers in 1967.
Note that you will also find this puzzle under the names, Four Cube Puzzle and Stop or Traffic Light Puzzle.
The full solution video for all three puzzles is shown in the following two videos.
Step 1: Tools/Materials
- Table Saw
- Drill Press
- Forstner bit - 3/4" Diameter
- Drill bits (1/2", 1/4" & 1/8")
- Pocket hole Jig (optional)
- Wood clamps
- Wood - 1" x 1" x 4.5" (blocks)
- Wood - 16" x 1.5" x 1/4" thick (bottom & sides)
- Wood - 1.5" x 1.5" x 1/2" thick (ends)
- Paint (Yellow, Green, Red & Blue)
- Stain (optional)
- 1/8" bungee cord and clip (optional)
Step 2: Blocks
The puzzle can be scaled up or down. I wanted a relatively small puzzle so I made the blocks 1" cubes. I built them from scrap hardwood and used a table saw to make the cuts.
Step 3: Holes
This step is optional. You could just paint the sides or add stickers. I wanted recessed holes for the colors. I used a 3/4" diameter Forstner bit to recess the pockets. I didn't like the small hole from the center of the bit so I went back and used a 1/2" drill to enlarge the center section of the hole.
Other options you will see for this puzzle include playing card suits (hearts, spades, clubs and diamonds) painted on the sides. I thought about insetting coins or poker chips into the recessed holes instead of painting. Since most coins are larger than 3/4", I would have have had to increase the overall puzzle size to go with that route.
Step 4: Block A
Getting the colors correct is the key to making the puzzle. Therefore, take your time when it comes to painting the blocks. Hopefully my drawing is clear with the side references. Note that the ISO view is showing the Left Side (blue), Front (yellow) and Top (yellow). This same naming convention is used on all blocks.
Step 5: Block B
Step 6: Block C
Step 7: Block D
That's it for painting.
Step 8: Painted Blocks
I removed the excess paint by sanding the faces.
Step 9: Enclosure
You will be building this enclosure. The parts are color coded for easy reference.
Step 10: Bottom
I used 1/4" hobby wood (poplar) for the sides and bottom. Cut wood to 5" long by 1 1/16" wide. Drill 3/4" diameter holes at the locations shown. I used the Forstner bit for these and drilled from both sides to produce clean cuts.
Step 11: Sides
Cut two sides per the drawing. Note that you can use the first piece as a guide if you don't want to remeasure the hole locations.
Step 12: Ends
These are made from 1/2" thick wood. The thicker wood allows for more room to place the retaining strap. Note that this is my feeble concept. I'm sure there are more efficient ways to hold the strap. Anyway, cut the wood and drill the holes as shown. I used a pocket-hole jig to make the angled hole. If you've checked the dimensions, you might have noticed that I used a perfect fit for the length direction. This worked out fine since I sanded the blocks slightly after painting the circles. This sanding reduced the overall length to be slightly under 4 inches.
Step 13: Assemble - Step 1
Actually I did this all at once but this gives you the process if you would like to take it step-by-step. Attach one side to the bottom as shown. Use wood glue and clamps.
Step 14: Assemble - Step 2
Add the second side with glue and clamps.
Step 15: Assemble - Step 3
The bungee and clamp were salvaged from an old book bag. You can find similar versions on sports bags and jackets. My strap concept was hidden so I needed to build it before gluing the pieces together. Feed two ends of the bungee through the end with two holes. Tie knots on each end and pull knots into the counterbore hole. Feed the other end through the angled hole.
Step 16: Assemble - Step 4
Add the end piece. Use wood glue and clamps.
Step 17: Assemble - Step 5
Add the remaining end to the enclosure. Again, use glue and clamps. As mentioned earlier, I glue the entire assembly at once. Sand and paint or stain. I chose a white wash stain.
Step 18: Optional Enclosure Build
I built another enclosure by cutting the middle section out of a 2x4. For this build, start with a 1.5" x 1.5" x 6" long block of wood. Cut it down to the dimensions shown in the earlier steps.
Mark your hole locations. I used the already completed blocks as guides. Drill all the holes about 3/8" deep. Note that I drilled from both of the sides to keep clean cuts.
Next, set your table saw blade to the correct height and start making passes. Sorry, this is a tedious process. I sanded the bottom groove area with a piece of sand paper wrapped around a block of wood to clean up the surface.
After doing a fit check, add the 1/2" thick end pieces. As you can see, I built this version without the strap. Use wood filler to clean up any gaps and sand the complete box. I debated on what color. The blocks are natural finish. I wanted something to contrast but I had already used white stain on the first version. I took the easy route and painted this one black.
Step 19: Puzzle 1
Drop your blocks into enclosure. For this puzzle, arrange the cubes inside the enclosure so there are 4 different colors in each side. Note that I'm showing the solution.
Step 20: Puzzle 2
Pull the cubes out of the enclosure and form a 2x2 square out of the cubes. For this puzzle, you must have 4 different colors on the top and bottom, and 2 different colors on each side
Step 21: Puzzle 3
Again, this one is outside of the enclosure and makes a 2x2 grid. For this puzzle, you must have 4 different colors on the top and bottom, and same color on each side.
Step 22: Pictures - White Version W/Strap
Step 23: Pictures - Black Version / No Strap
Step 24: 2x2 Grid Puzzle Pictures
Thanks for reading this far :)