Triangle Strategy Game Replacement Pieces

Blokus™ is a strategy board game where players try to get as many of their pieces on the board while blocking their opponents from getting their pieces on the board.

It has won many awards. My sister and her family introduced me to it. They play a lot of games and always know the best ones. They have both Blokus™and Blokus™Trigon™. Between the two, they think that Blokus™ Trigon™ is the better game because it is harder.

After we played I went online to see if I could get the game for myself. Mattel no longer makes it. The best offer at the time was $200. (Note: Now it is available on Amazon for around $45.) I was able to find some on eBay, but they all seem to have missing pieces.

Today it is easy to go online and find manuals for things. Most manufacturers have their owner’s manual posted in the Support section of their website. These can be downloaded and printed out if you’ve lost yours. Many electronics manufacturers even have firmware updates that can be downloaded and installed. Now with 3D printing, it should be possible to replace parts just as easily as replacing owner’s manuals.

I decided to buy one of the Blokus™Trigon™games with missing pieces and print my own replacements.

(Note: Blockus™ and Trigon™ are registered trademarks of Mattel, Inc.)

Step 1: Printable Replacement Pieces

I’ll start by providing the 3D printable files for each of the Trigon™pieces. You can easily get them printed through 3D Hubs by selecting the link next to them.

These are small pieces. I recommend having them printed with no raft and at least some fill. Since they are flat on top and have grooves in the bottom to fit on the game board, they should be printed with supports as well.

The original game comes with four sets of 22 game pieces. The sets are in different colors: Red, Green, Blue, and Yellow. Be sure to specify which color replacements you need.

I’ve numbered the 3D model files to match the numbering in the Blokus™ Trigon™ Instructions. Go through your game pieces to find out which ones you have and which ones you need. Remember that the pieces can be flipped over to be used as the mirror image of the one pictured in the instructions.

Try to get all of the pieces you need in one order. This will save in shipping or costs picking up the pieces from your local 3D Hub.

These are not official game pieces. They are approximate copies that will play the same as the originals. You may need to file down or sand the edges of the pieces so they fit smoothly on the game board with the other pieces.

Step 2: Gather Measurements

Now that you have the models, here is how I built them.

I started by getting an official game from eBay. The listings with missing pieces were less expensive than the full sets. This at least gave me the game board and some pieces to start with.

I measured the single triangle piece (Piece 1) and I measured the lines on the game board. I determined that the triangles have edges 17 mm in length. (Note that most 3D printers use units of millimeters, so I kept my measurements in millimeters.)

The game board has raised lines that help hold the game pieces in place. The pieces have grooves on both sides. This allows them to be placed in mirror images of the basic shape.

Step 3: Start With Single Triangle Piece: Moniamond

I used AutoDesk 123D Design. I don’t have any real CAD experience. There was a lot of trial an error in this process. It was a good project to get familiar with the tool. I’ll skip all of the errors that I made and just cover the final process that worked for me.

I started with a polyline to create the primary equilateral triangle. I made sure to type in values for the line lengths (17 mm). As I moved to the second and third line of the triangle, I also specified the angle (60 degrees) with the length.

Once I had this basic shape, I copied it and moved it up the Z-axis 2 mm. The triangle that was left at the base was scaled 80%. I decided to scale it a little more than necessary since my measurements were from a ruler and not calipers. This would leave a little larger groove in the replacement pieces allowing them to still fit on the game board, even if the measurements weren’t perfect.

I then extruded each of the triangles 1 mm up the Z-axis. By moving the larger triangle up 2 mm instead of just the 1 mm required, it kept the two solids separate. This allowed me to copy the smaller solid and move it up 3 mm, or on top of the larger triangular prism shape.

Next I moved the top two triangular prism solids down 1 mm so I had Piece 1, the single triangle piece. This single triangle piece became the basic element for all of the rest of the replacement pieces.

I printed this piece and tested it on my game board. It fit, so I continued making more pieces.

Step 4: Piece 2: Diamond

From Piece 1, single triangle shape, I used the Save a Copy command to start the model for Piece 2, the two triangle piece, or diamond.

I selected all of the shapes, copied them, pasted them, and moved them along the X-axis about 10 mm. Then I used the Snap tool to connect the face of the middle solid of the copy to the face of the middle solid of the original piece.

At first I couldn’t get this to work. Only the center solid (with the 17 mm edge) would move. I deleted the copy. I had to use the Merge tool to merge together the first piece. Then I could copy, paste, move, and snap it into place.

I saved Piece 2, the Diamond and continued.

Step 5: Repeat

I used the same process of copy, paste, move, and snap to create the three triangle, Triamond, piece and the first four triangle, Tetriamond, piece.

There are three different pieces that have four triangles: Piece 4, Piece 5, and Piece 6.

After creating Piece 5, I printed it and tested the fit on the game board. Only large errors in measurements would have appeared in printing and testing the fit of Piece 1. Now that I had multiple triangles together in a game piece, the small errors would be accumulated and this gives me the opportunity to test for the fit after these errors were accumulated.

Piece 5 fit well on the game board. It didn’t like to be crowded in by the other original pieces. A little bit of filing with a nail file took care of this quickly. I decided to keep with the design I had and build the rest of the pieces.

Step 6: Create Pentiamonds

Game Pieces 7, 8, 9, and 10 have five triangles in them. I started with Piece 4 and copied one of the triangle pieces, moved it along the X-axis and snapped it in place to create Piece 7.

The other five triangle, pentiamond, shapes were easy using the Save a Copy and Snap commands. The hardest part was understanding the difference between Piece 8 and Piece 10. In 123D Design, my Piece 10 is rotated 180 degrees from the way it is pictured in the Blokus™ Trigon™ Instructions.

Step 7: Create Hexiamonds

Game pieces 11 through 22 have six triangles. The process I used to go from Piece 4 to Piece 7 was repeated to go from Piece 7 to Piece 11.

After that it was a matter of using Save a Copy and Snap commands to create each of the remaining pieces.

Step 8: Create STL Files

Once all of the game piece files were created, I needed to export them from 123D Design into the Stereo Lithography (STL) file format used by 3D printers. I really like that AutoDesk 123D Design has this option built in. Some of the other tools I've tried required an additional plug-in to be able to export to STL.

With the simple shapes in the game pieces. I kept the fine detail from the model, combined shapes, and exported in ASCII format.

The biggest challenge to this step was making sure I didn’t miss any of the 22 different game pieces. I used the same file naming convention as the 123D Design files. I also kept the Game Piece number from the Blokus™ Trigon™ Instructions to make it easier for me to find the right pieces and for others to get the game piece files they needed for their missing pieces.

Now that the 3D models are done and everything is exported to STL format, it is just a matter of printing the replacement pieces and getting back to playing the game.

Step 9: There’s Math in Them Thar’ Hills

The Blokus™Trigon™game pieces are Polyiamonds. More information about Polyiamonds is available on Wikipedia at https://en.wikipedia.org/wiki/Polyiamond. You’re probably most familiar with the diamond, which is made of two equilateral triangles sharing one side. The game has pieces with one triangle (Moniamond), two triangles (Diamond), three triangles (Triamond), four triangles (Tetriamond), five triangles (Pentiamond), and six triangles (Hexiamond).