Inductive Chess

This is a full chess set containing a board with a large induction coil in the base and chess pieces with LED's inside each piece receiving wireless power through the chess board through induction.

All pieces are build up from 1 ‘base’ element, you need 16 of each color to make a full set. Then on top of the ‘base’ element you add the corresponding piece you want to create.

The pieces have transparent parts that are labelled as 'illum' / ‘illumination’. 

I have printed my pieces in PETG white/black and transparent for the illuminating parts. After printing you can sand the parts for a more matte finish. Each of the pieces can be stacked together.

For the wireless LED's I have used these ready made ones from Aliexpress:
https://nl.aliexpress.com/item/1005003468667196.html

These are SMD leds stacked on top of an inductor and ment for a ‘large range’ power transfer.
The listing states these as made for the 24v module with a 0-150mm induction distance. Size of the LED's with conductors is approx. 5.4mmx5mm. 

The power module is :
https://nl.aliexpress.com/item/4000121353613.html

This module has a coil diameter of 200mm and is powered through a 24vdc adapter. they name this module “XKT801-05” when searching for it

Before permanently sealing in the LED's in each piece, make sure to test each LED to see if they work properly. I have had a few bad ones and you cant remove them anymore later on in the process.

Assembly order:

1. Build all the base elements, glue the base element together and then drop a 'wireless LED" inside
2. Power the 200mm coil and place the ‘base’ in the center
3. Test the LED's you want to use for the piece. Lower the LED into the bottom (led pointing downwards) and test at what height it shines the brightest. Then glue the LED in place with a dot of (transparent) glue of your liking. I suggest the gel thickness glue for easy placement and the ability to adjust it slightly before the glue hardens.
4. Assemble the top part of the piece. Repeat step 3 by placing the LED inside. until the right height has been found to make them shine through the brightest.
5. To help you get the LED's in the right position, I used the stick from a cotton swap which I pushed the LED upwards into the piece, when I found the best position I marked the swap on that location and then repeated the step for the other equal pieces for fast and easy placement. Drop some glue on the LED, push the led up until right position, leave the piece lying sideway while the glue dries. repeat for all pieces.

The pieces only shine when they are position in the right way with the induction field of the coil. This means when you put a piece down sideways it will stop glowing. LED's can therefor only be orientated pointing up or down inside a chess piece.

Chess Board building:

1. Pretty straight forward. Print 32 white squares and 32 black squares and put these aside.
2. Print the top of the board, orientate it upside down (holes for the squares pointing down) so you require as little support material as possible).
3. Print the bottom of the board.
4. print the Spool holder. this piece slides right in between the top and bottom when assembling.

The original 200mm spool is too small for illuminating the entire board, is the wrong shape and where it overlaps with a chesspiece the piece won't light up. Therefor I designed the spool holder. You can wind a new spool from the right size into this holder. I created my spool from 1mm thick copper spool wire(copper with a lacquer coating).  5 windings should do. Make sure the windings do NOT overlap with eachother, this cancels out the field strength and will make the pieces glow up way less or stay of completely.

there is a cutout in the spool holder where you can let the start and end lead point inwards and connect to the Driver PCB. Connect the new spool by desoldering the old spool from the PCB and connecting the new one to connections on the board. You can then test the working of your spool by powering it and moving a chess piece or 1 of the LED's over the spool area to see it glow up. In the center the glow will be slightly softer than near the edges.

Once done you can assemble the rest of the chess board.

1. Add a barrel jack and power switch to the side of the board through the two round holes.
2. Place the spool holder into the top part of the board
3. Place small nuts inside the bottom part of the board
4. Place bottom side of the board inside the top part, then screw down on each edge. (There is some clearance between the inside and outside board parts to account for different printer precision. If you screw down too tightly the board will not be perfectly flat. This most often wont be an issue but if it does bother you. Edit the supplied STEP file of the board to adjust the file to your liking/perfection).
5. Screw the board together and dont overtighten the screws
6. Place a drop of glue into the center of the chess board square, then add the right colored square to the, if you press around the edges these squares should fit right it/snap into position and the glue will then keep them locked in place.
7. Test the board by powering it on and moving an LED of chess piece over the different positions on the board.

The design of all pieces/the board has been made in such way that it is printable on a single extruder printer. The board size however is quite large and I did not optimize it for small printers. You will likely need a 400x400mm build surface for the board. Alternatively you could cut the board up in smaller sections, redesigning is possible through all the supplied STEP files.

All chess pieces have 1 LED in the base of the piece. For all the pieces with a second transparent part, there is 1 more LED to be placed inside the top part of the chess piece pointing upwards.

All STL files are supplied for easy printing, also all STEP files are added for whoever wants to remix/adjust to there liking. Since I always tend to get frustrated by only having STL files of models that I want to improve/adjust I want to save you the pain of this and enable you to be creative :-).