It all started with an idea I had many years ago.
I had just picked up a cheap-o glass chess set at my local arcade for the low low price of only 15,000 tickets. The novelty of playing with glass pieces quickly wore off, and I wondered how I could make it better. The thought of illuminating the set seemed very appealing, but there were so many different ways that could be done.
I could put alternating colored lights under the board following the checkerboard pattern. The light would shine up through the glass board and make the pieces glow. The problem with this design is that the pieces would change color with each move, and (since the difference between the two sides is not black / white but frosted / clear) this would make game play somewhat confusing.
I could put a small battery and light inside of each piece, so the two sides would each be different colors. This would probably be the simplest way to get glowing pieces; however, this design is not without its problems. The batteries would need to be replaced. Their lifespan could be extended if a small sensitive on/off switch, activated by the chess piece being in an upright position, were added. This would complicate the design though, and still only be a temporary solution, as the batteries would need to be replaced eventually. This design (with the switch) does have one more advantage. It gives the chess pieces two states, on and off. I liked the idea of the chess pieces being illuminated while they were in play (upright and on the board), and dark while they were out (dead and off the board).
The final design I chose (which will be explained in more depth in the next step), was to have each piece contain an LED that would be powered by a conductive board. The board is plugged into an outlet, so there is no need to worry about the power running out. While the pieces are on the board they are "live" and illuminated, and while off the board they are "dead" and dark.
I made a stop motion animation of game six between Kasparov and Deep Blue. The animation does not end with checkmate, because when Kasparov saw that he was going to be beaten by a computer, he threw a hissy fit and stormed off.
Step 1: How It Works
A conductive chessboard is made from a sheet of copper. The sheet is wired to the positive lead from a power transformer. Insulated holes through the center of each square on the board allow magnets to pass through. The magnets connect and hold a negatively wired steel plate underneath to the negative leads from the LEDs.
Step 2: Materials
The materials include:
Glass chess set - I got mine at Walgreens. It was a two for $10 deal. I bought a couple so if I broke some of the pieces I would have extra. The chess pieces should have a small cavity in the bottom covered by some circular felt stickers, to prevent them from scratching the glass chess board.
LEDs - Twenty 5mm blue and twenty 5mm green LEDs. I ordered mine from superbrightleds.com.
Magnets - I used 1/8" tall 1/16" diameter cylindrical neodymium magnets. Since three were used in each square on the board, 192 were needed all together. Of course the magnets could be 3/8" tall and only 64 would be needed.
Wood - A thin sheet (~1/4" thick) with the same area as the copper plate, used both as an insulator and as a structural backing for the copper. Thicker pieces of wood are also needed to make the final box / enclosure for the chess board, but the dimensions do not matter too much, as almost any scrap wood will do.
Copper plate - A square copper sheet around 1/16" or 1/32" thick, and with an area at least that the size of the original chess board. I found mine on Ebay.
Copper washers - The outer circumference should be the same size as the outer circumference of the base of the chess pieces. The inner diameter is not as important, but should be large enough to easily wire an LED through.
Steel plate - Should be exactly the same dimensions (length and width, thickness doesn't matter too much, but around 1/16" or 1/32" would be ideal) as the original chess board (only the 8 x 8 grid of squares, not counting any extra border). If each square on the chess board is 1" by 1", then the steel plate should be 8" by 8".
Copper foil tape - Again the exact specs change depending on the size of your chess board, but a few feet (~6') of tape should be good. The width of the tape should be half the width of one square on the chess board (1" chess board squares = 1/2" copper foil tape)
Acrylic sheets - It doesn't really need to be acrylic, but that was the building material available to me at the time. One square will be to sandwich the steel and copper plates together, and to hold the wires in place. The other square I used as a bottom to the chess board box.
Power supply - I used a wall wart with a 120V AC input and 3V 300mA DC output to power the chess board.
Gaffers tape - To tape stuff in place
Glue / epoxy - To hold the copper plate to the wood sheet. Wood glue is also used to make the box.
Step 3: Tools
Sandblaster - You can either use a professional "real" sandblaster, or you can make your own using a paint sprayer, rubber hose, and bucket of garnet following Star's instructions here. I highly recommend making your own. It is dirty, it is simple, and it is fun.
Soldering iron - Used for doing the obvious.
Deburring tool - Used for burring De's. Deez what? Deez nuts.
Drill and bit set - Some carbide tips are useful if drilling out the glass chess pieces is necessary.
Multimeter (optional) - Used to measure the voltage given off by the board, once constructed.
Dremel and bits- Various dremmeling needs
Steel wool - To polish the copper plate
Metal file - For breaking out of prison, and to help with deburring.
Step 4: Starting the Copper Plate
I had a difficult time thinking of the best way to get the checkerboard pattern on a single conductive surface. The plate could easily be divided into 64 uniform squares, but that would look terrible. I briefly considered using two separate conductive metals (copper & steel, or similar), and making a checkerboard pattern by alternating squares of them, but that would take too much time and effort. I finally decided that sandblasting, the same technique used to make the original glass chessboard (I think, although it may have been chemical etching), would be the best way to get the pattern down on a conductive metal surface.
Sandblasting a checkerboard pattern into the copper sheet will result in 32 squares with the original shiny copper gleam, and 32 frosty squares that were exposed to the abrasive. The hardest and most time consuming part about this step was not sandblasting, but setting up a stop.
A stop is what prevents the abrasive material from etching / frostifying unintended areas of the plate. There are many ways of setting up a stop. The technique I describe involves using a large format printer with a vinyl sticker medium. While this method is probably inaccessible / unfeasible for most of the people reading this, the entire process should not be too hard to replicate with common household tools and materials (printer, exacto knife, tape, and (at most) a trip to Kinkos).
(Like always, the pictures say a thousand words, and are much more descriptive then I could ever hope to be with written instructions)
Polish the copper sheet - Polish the nicer of the two faces of the copper sheet with some steel wool, so that it is shiny. Shiny things are fun.
Create a checkerboard pattern file - Using Illustrator I made a checkerboard pattern file with the same dimensions as the original glass chessboard. The printer I used was able to cut the lines on the adhesive sticker medium, so, once printed, all I needed to do was peel off every other square from the pattern. If you do not have access to a printer with automatic cutting then you can use a regular printer to print out the pattern onto an adhesive medium, and trace the lines with an exacto knife. The vinyl sticker paper I used was a perfect material for this job because it can be peeled off without leaving behind any residue, but it is strong enough to stay attached to the copper while being sandblasted. Make sure to test your material before using it, otherwise you will either end up with adhesive residue left behind on the copper plate, or a fuzzy edged out of focus looking checkerboard pattern (The out of focus appearance will happen if the edges of the square stickers begin to peel up while being sandblasted).
Transfer the adhesive checkerboard stickers to the copper plate - I used a large sheet of transfer paper to get the vinyl sticker pattern squared perfectly with the copper plate. Transfer paper is just like very large masking tape. If transfer paper is unavailable, overlapped masking tape can be used instead. Overlap the tape so that it so it forms a large square which is a bit bigger than the checkerboard sticker. Place the nonadhesive side of the checkerboard sticker against the adhesive side of the transfer paper, so that both sheets are sticky side up (The pictures should make this process very clear). Remove the backing on the checkerboard sticker, and peel away every other square. Lay the checkerboard sticker / transfer paper combo on a hard flat surface, sticky side up (duh). Carefully lay the copper sheet directly over the checkerboard sticker, so that the sheet aligns with it perfectly, and press down firmly . When you are confident that sticker has completely adhered to the copper sheet, flip it over and peel away the transfer paper at a sharp angle. Make sure all the checkerboard pattern stickers remain completely stuck to the copper sheet.
Sandblasting - By far the most fun part of this step. If all the preparation was done correctly, the process of sandblasting is hard to screw up, and provides very impressive visible results. Take the copper sheet and sandblasting apparatus outside to a smooth flat area that you do not mind getting covered in garnet. One of the good things about sandblasting (copper at least) is that it is hard to overdo it. Unless the stickers start to fall off, it is almost impossible to "overfrost" the copper. You will reach a certain level of "frostiness" and will not be able to go beyond it. It is possible to "underfrost" though, and once you take the stickers off it is hard to go back, so just be sure that every exposed part of the board is evenly blasted.
From this point on you should probably handle the copper plate by the sides, as fingerprints have a tendency of turning into nasty black smudges.
Step 5: Drilling the Copper Plate
Mark off the center point of each square - The holes will go through the center of each individual square on the board. There are many ways of marking off the center points. I decided to draw an X on one of the remaining unused square stickers, line that square up with the squares on the board, and poke it with something that would leave a mark. A crossbow bolt is what I had, so a crossbow bolt is what I used. Do this for all 64 squares on the board.
Drill through the board - The goal is to get 1/4" holes through the center of each square. I used a hand-held drill with regular bits to do this. Before drilling, clamp the copper plate down to a flat piece of scrap wood, so the bit will have something to drill into once it passes through the copper. The scrap wood will help prevent the copper sheet from bending out of place while it is being drilled. It is best to use clamps with rubber feet, so they do not scratch the copper. If a metal clamp must be used, put a piece of cardboard between the foot and the copper. Keeping the drill perfectly perpendicular to the plate, drill out all 64 holes.
Clean up the plate - After drilling, many of the holes will have burrs on them. Remove these either with a metal file, or a deburring tool. I found the deburring tool to be much more effective ... I wonder why.
Step 6: Making the Board
The wood - Like everything else in this project the specifications depend on exactly what parts you used and how you used them. If you happened to use thicker copper, then it may not need structural support, and a small veneer insulator backing would probably work. The copper I used was thin and pretty flexible, so I needed to back it with a sturdy piece of wood. I had this pretty nice 1/4" thick polished wood laying around, so that is what I used.
Prepare it - I lay the copper sheet on top of the wood, and traced the area out with a fine tip sharpie. I then cut off the excess wood with a chop saw, and smoothed the sides with a belt sander.
Prepare it more - Scuff up the back of the copper plate and one side of the wood. I used one of the flat tire repair kit inner tube scuffers, but any way of scraping up the surfaces should work.
Glue them together - I wish I had put more thought into this step before I went ahead and got epoxy everywhere. Almost any method of gluing the copper and wood together would have been better than what I did. I just spread / mixed the epoxy out on some aluminum foil, and smeared the back of the copper sheet and the wood in it. Doing this allowed epoxy to go through the holes in the copper plate and mess up the front.
If I were to redo it, I would cover the front with masking tape or transfer paper to completely prevent any glue from going through the holes (On second thought, the front of the copper plate should probably be shielded with some sort of adhesive cover right after drilling. Doing this will help prevent scratches and smudges, and will also keep the glue from going through the holes). I would have also painted on the glue on the back of the copper plate to prevent it from ever even getting near the holes.
When both the copper sheet and piece of wood have glue on them, press the two faces together and hold / clamp firmly until they set.
Drilling the wood - After the glue has dried completely it is time to drill through the wood. The diameter of the drill bit should be the same as the diameter of the magnet. The magnets I were using were 1/16", so the bit I used was also 1/16". Drill holes through the wood in the center of the hole in the copper. Place the magnets in the holes to make sure they fit.
Step 7: Wiring the Board
Preparing the steel plate - Thoroughly clean one side of the steel plate. Place magnets in each hole on the board. I needed columns of magnets three tall, to get through the combined thickness of the copper plate and wood backing. Place the steel plate squarely underneath the wood (The clean side of the steel plate should face the wood and copper). The magnets should jump from the holes in the wood to the steel plate. Their location on the steel plate will indicate where to lay rows of copper tape.
Laying the tape - Cut eight strips of copper tape to the length of the steel plate. Lay them down on the clean side of the plate directly under the location of the magnets. Cut two longer strips, and lay them down so they overlap with the tops and bottoms of the eight rows (see pic). These two strips should be long enough to wrap around to the back of the plate.
Wiring the (-) plate - Cut two 2' segments of wire. Solder them to the copper foil that overlaps on the back of the steel plate. They should be soldered on opposite corners of the plate. Optional: To help keep the wire from pulling the copper tape off the board, duct tape the wire to the plate a few inches away from the solder points.
Wiring the copper board - Clamp the copper sheet / wood to a sturdy work surface, and drill two holes into opposite corners. Make sure to drill into the copper and then through the wood. If you do it the other way, you risk pushing or bending the copper sheet away from the wood. The diameter of the holes should be just large enough to allow the wires to pass through. The holes should also be in the two corners that are not occupied by the wires connected to the steel plate. Put the ends of the wires through the holes and solder them to the copper plate.
Putting the pieces together - Put magnets into each square on the copper plate. Place the steel plate on the bottom of the wood, so that all the magnets line up with the rows of copper tape. The magnets will snap to the steel plate, and (as long as you lined everything up correctly) the magnets should sandwich the copper foil tape. The magnets will also hold the steel plate to the bottom of the wood / copper sheet.
Optional - Although unnecessary, I found this final step part very helpful. Cut a sheet of acrylic to the same size as the chessboard (thickness of the acrylic does not matter). Line up the sheet of acrylic with the bottom of the chessboard, and mark off where the four wires come from the board. Drill out these spots with bit the same diameter as the wires, and "thread" the wires through the holes in the acrylic. This will help keep the wires and the steel plate in place, as well as organizing all the "functional" parts of the chess set into a single package.
Step 8: Starting the Box
Prepping the wood - Four even pieces of wood, each slightly longer in length than a side of the copper plate, are needed to form the sides of the box. Measure the combined thickness of the copper / wood plate, and cut a shelf of that thickness into the wood. The shelf should be as high up the wood as possible, but have a thick enough overhang that it will not snap or break when the chess board is being pushed into it. The reason for the overhang is to hide the two wires soldered to the board. Cut the ends of the four pieces of wood at 45 degree angles. On two of the pieces of wood, shave a bit of the underside of the overhang and cut a small grove into the shelf, so the soldered wires have room to fit in when the box is closed.
Putting the pieces together - Lay out a strip of painters tape sticky side up. The length of the tape should be a few inches longer than the combined length of the wood sides. Lay the four wood sides down on the tape, making sure to line up the orientation of the two notched sides with the two wired corners of the board. Put the board into one of the sides, and put wood glue on each of the 45 degree angle cuts. Fold the side pieces around the board, and use the excess tape to hold them in place. Square all the corners (using a rubber mallet if need be), and place clamps across all four sides. After the glue has set remove the clamps and tape.
Step 9: Wiring the Box
Drill - Drill a hole (of the same diameter as the wire from the power supply) into the side of the box. Put the wire through the hole, strip an inch and a half off the end, and separate the two different polarity wires. Using a multimeter, determine and mark which wire is the positive and which is the negative.
Solder - Solder the two wires from the steel plate to the negative wire from the power supply, and solder the two wires from the copper sheet to the positive wire from the power supply. Cover the soldered bits with electrical tape to prevent shorting.
Tape - Tape everything to the underside of the steel plate, or (if you made the optional square to organize the wires) tape everything to the bottom of the acrylic. Gaffers tape is always a good choice.
Test - Using an LED, test the board to make sure that it is wired correctly and working.
Step 10: Finalize the Box
Creating a ledge - With the help of numberandom, I used a milling machine to create a ledge on the underside of the box. If you have access to a milling machine and choose to use this method, make sure to clamp both sides of the box, so it stays nice and solid during the milling. If you do not have access to a milling machine, then you can use a dremel, or some similar tool to to work away a ledge deep enough to fit a sheet of acrylic in.
Make the bottom - I cut and fit a sheet of acrylic to the same area as the inside of the ledge. I had a handful of magnets left over after wiring the board, so I decided that is what I would use to hold the bottom in place. I turned the box chess face down, and placed the acrylic bottom into the ledge. Using a drill bit with the same diameter as the magnets, I drilled two holes in each corner, straight through the acrylic into the wood.
Magnetize the bottom - Eight holes in the acrylic and eight holes in the wood makes for a total of sixteen magnets. I glued the magnets in with some gel super glue, alternating the polarity, so the bottom could only fit in one way. I cut up an old hard drive ribbon cable and glued it to the acrylic to make a pull tab for the bottom.
Step 11: Preparing the Pieces
Remove felt - The chess pieces probably have a black felt circle on the bottom to prevent glass on glass action. Remove this piece of felt. Remove any remaining adhesive using some acetone.
Test depth - The chess pieces should have a small cavity underneath the felt. I am pretty sure this is an artifact from the molding process. None of the cavities are the same depth, so you should take an LED and test each piece to make sure the cavity is deep enough to completely hold it. If it is not, you have two options. You can either spend you time carefully drilling out the piece with a quarter inch carbide tipped drill bit, or you can buy another set. After drilling a few pieces, I figured it would just be easier to get another set since they are so cheap. Hell it was a two for $10 deal, so I bought a couple of extra sets.
Step 12: Making the Pieces
Gluing the LEDs - Using the gel superglue I glued sixteen blue LEDs into the clear pieces (I chose blue for the clear pieces because it would resemble ice), and sixteen green LEDs into the frosted pieces. While gluing try to make sure the negative lead (the longer one) is directly in the center of the piece because it will be making contact with the magnet that is in the center of the square.
Trim the leads - Bend the positive lead to the rim of the base and clip the excess, as shown in the picture. Clip the negative lead so that it is just slightly extending past the bottom of the piece, and bend the excess at a 90 degree angle, so it will have some area that comes in contact with the magnet.
Glue the washers on - I covered 3/4ths of the bottom of the chess piece with glue. The remaining quarter was the area near the positive lead. I left it unglued because I did not want to risk ruining the connection to the washer. Firmly press the washers onto the glue (but do not rotate!) and let sit undisturbed until the glue is dry.
Solder the lead - Solder the positive lead from the LED to the inner rim of the copper washer. This will be a delicate, slow going operation, but be patient and do each one carefully.
YOUR FINISHED!!! - Plug the board in, and put the pieces on it to make sure they all work. Sit back and bask in your awesomeness which is a direct result of my awesomeness.