Chess
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A friend of mine is an exceptional chess player, and his birthday was coming up. To celebrate, I decided to make him a chess board. In reality this was an excuse to take on a giant design and 3d printing project and learn some things in the process.
Design
I don't know a lot about chess. In fact, I didn’t know that pawns can only move forward until the last week of this project. Without any extensive background in the game, the whole design was largely intuitive. The repetitive, geometric nature of a chess board actually lends itself well to sizing the design.
I did some perusing on interesting chess boards and was inspired by a few. The Contemporary Aluminum Chess Set, by Justin D. Philips is a nice example using only box-shaped pieces of different heights and embossed symbols. I also came across spice chess, where a player orients themselves to the board by smelling the spice held by each piece. I determined the embossed symbols wouldn’t 3d print well, and the spice chess was probably at best too difficult to play.
Chess Set by Tom Sachs also really stuck to me. Using magnets to keep the pieces in place, Tom Sachs could use this piece to fit with his space program demonstrations. Having a board that folds while the pieces stay in place was captivating. With this idea solidified, the design flowed easily.
The board was made of squares, so pieces should fit within cubes that sit on each square. I printed a few tests, and 30mm x 30mm x 30mm blocks felt right in the hand, and 40mm x 40mm squares fit those pieces well.
To keep the look minimal, each was to be cut or morphed from a cube, and each with a design element that alludes to its unique movement or intention. For example, Bishops move on the diagonal so those pieces are cubes twisted 45°. Because the queen moves just about anywhere, it draws on the same principles as the bishop but is accentuated with 3x the twists. The king too can move to any square, but slower than the queen, so that piece has a more modular feel.
TODO: Gallery of each piece on its own
Piece-Board Interface
Magnets came onto the scene early in the design process. I wanted pieces to sit straight and center in their chosen squares like the Tom Sachs board. I also loved the idea of pieces that satisfyingly snap into a new spot. I started with circular magnets that I had on hand, and attempted to make a shaped cutout in the board to orient the piece.
This did sort of work to orient the pieces, but felt terrible and scratchy. I then had an epiphany: rectangular magnets. Using only two magnets and no fancy printed parts, the magnets ensure there are only 2 ‘correct’ positions for each piece to sit, either forward or backward. If a piece is placed facing 90° off center, it will naturally want to snap into orientation.
That is a slice of an early test I did. This evolved into the final base design, where the magnet sits in a little 'boat' and mounts into the base of each piece.
The boat serves another sneaky purpose besides magnet retention. By raising the piece base up above the surface of the board, a player can easily detach the piece by pushing on either side of the piece, moving the magnet out of the strongest portion of the field. Additionally this leaves a very small amount of surface left in contact with the board. The reduced surface area means reduced friction when the piece is self-orienting, resulting in a snappier feel and less slop in the final holding position.
Attaching the boat like this is also more versatile, as it easily fits into the design of each piece. All I need is a punch-out for each tab/bolt in the piece base. No seams or anything weird required.
The bolt screws into tiny M2 heat set inserts which easily melt into each piece with a soldering iron.
Board Design
The board went through many iterations. At first, I wanted something that could fold up and travel. The magnetic pieces lend themselves well to this. However most designs I came up with either required all pieces to be moved to accommodate a perfect fold, or ended up folding into an awkward thick boxy shape.
Quite late in the design process I realized this would look really cool sitting on a shelf as a big 'tower' of four board sections. While not ideal for travel, it does solve for storing the board in a compact way that’s also aesthetically pleasing. This also simplified the design quite a bit. I could use magnets to hold the board in either flat or 'tower' orientation.
Using magnets to join the board has an added benefit of making the board feel as if it wants to be played as it is laid out.
The board contains almost 800g of filament, 128 magnets, 48 heat set inserts and 48 M2 bolts.
Printing
I didn’t take any progress shots of the prints, and don’t have a fancy timelapse setup. All the parts were printed on a Prusa i3 Mk3s. The white pieces are Prusement PETG - Signal White and the board and black pieces are Prusament PETG Galaxy Black.
If I did it all again, I’d try printing the board in a slightly lighter grey to bring out the board lines.
Board Assembly
The board came together well with some caveats noted below. Probably the largest design flaw is the joint between each 4x2 section. Because it relies only on 2 m2 screws it can be easily bent or broken. In hindsight, this would have been a good opportunity to use 4x2 base sections, and 2 3x2 + 1 2x2 top sections for each 8x2, allowing the top to naturally reinforce the base joint. Upon receiving the board my friend almost snapped an 8x2 in half because he expected it to come apart like the rest of the board.
Final Thoughts
What started as an innocent project turned into quite the beast. CAD has a magical property of making everything look equally sized and easy to build. It is easy to forget that parts can take a lot of print time. For example each 4x2 board section took 8h to print. This meant to get the project done within a few weeks I had to run the printer constantly, even while I sleep.
The scale of the project also got away from me in terms of parts. Each piece takes 2 m2 inserts, and 2 screws. Each 8x2 board section takes 14 more inserts and screws. That is 100 inserts and 100 screws for the project, assuming I make no mistakes.
The project came together well, and effectively sets an unreasonably high bar for all future handmade gifts I might make. I hope this sparks some ideas for you!
Useful Tools
This section contains referral links to tools I found useful while building this project.
Wera Micro Hex Screwdrivers - These were a lifesaver. I like them so much I built a custom case for them (future post topic?). The M2 screws I used for the project have a 1.3mm hex drive which I couldn't find in any other set of drivers or my collection of bits.
M2 Heat-Set Inserts - These deserve an entire post. They make holding small parts simple. Print aligned holes in your parts. Then just press them in with a soldering iron. The exact type I’m using are from a local distributor, but this link is a better deal if you want a combo pack instead of a specific size.
Hakko Soldering Station - I’ve had this one for 5+ years now and it has been rock solid. It sleeps when you put it into the station which is perfect for projects like this that are 99% fiddling, and 1% melting.
STLs
Here are links for the individual pieces and parts. Print at your own risk.
- king
- queen
- bishop
- knight
- rook
- pawn
- baseboat
- board-top-male
- board-top-female
- board-bottom-male
- board-bottom-female
And an archive of everything together is here.