Introduction: LED Chess Set - Simple Version

Tetranitrate previously posted an excellent instructable on how to make an LED chess set here:

https://www.instructables.com/id/LED-Chess-Set/

I found it through BoingBoing, but couldn't be bothered making one that looked so flash. I just wanted one to work, quick and easy. So all credit to Tetranitrate for the concept and what follows is a quick and easy solution to get a 'similar' result.

This Instructable shows you how to turn a glass chess set into one with glowing pieces that go out when you take them off the chess board.

It uses:

40 LEDs $7.50 Australia (I love Jaycar - electronics supplier)
a resistor or two Free from junk
some copper wire 2m maybe. Free from junk
glue - I used Crystal Clear Araldyte $17.00 or so. Have heaps left.
a glass chess set $5.00 from toy store
Unwanted phone charger Free from Junk - if you don't have one, a friend will.
Solder Free from around

If you have glue, the rest should be less than $15

Tools:
Soldering Iron (can manage without)
Pliers for twisting wire
Knife for stripping wire
Something to cut wire with

Some soldering is required but if you can't, you could still get a working one by just twisting the wire.

Took me about 4 hours to assemble.

Step 1: Get Some Copper Wire

You need strands of copper wire that are twice as long as the length of your chess board plus a little for twisting the ends together.

I got mine by using a cutter knife to slice the edge off some electrical cable and then peel the plastic off to expose the wire.

I then pulled the wire out of the plastic.

Wrapped it around the chess board with about 3cm/1 inch going past the edge of the chess board. I did this to get the correct length.

Cut the wire at the desired length. Remove it from around the chess board and separate the wire into strands. You will need 16 strands of copper wire. The stuff I used had strands about the same thickness as wire in a (twistem, bread tie, freezer bag wire).

Step 2: Wrap Strands Around the Board.

I didn't, but you may want to get your wire really straight to start with. It would have been a bit better if I did.

With each of the 16 copper wire strands, fold them in half and put a kink in them. Loop the wire around the board and push the kink up to the edge.

With the wire running straight across the board twist the two ends of the wire together. Keep all of the twists at the same end of the chess board.

Use pliers to pull the wire tight and twist it up. If you twist it too tight or too much, it will break.

You want two strands of wire for each row on the chess board. Have the wire cut the square into thirds or even slightly closer.

Run the wires from one opponents side to the other. So that if you were to slide the queen from her side to the far side she would slide along two copper strands.

Step 3: Match Up the Rails

Get two lengths of cable and cut them the same length as the chess board. You want them longer than just end to end of your wires that you wrapped around the board.

Make sure your twisted ends of the wires on the board stick out straight.

Lay one of the cables along the edge of the chess board under the twisted ends. Make it match up with the edges of the chess board.

Starting with the first twisted end, make a mark on the cable for every second twisted end. Mark the right hand end of the cable a bit so that you know which way around it went.

Now lay the other cable down the same way, but this time put a mark for each twisted end that you missed on the first cable. Make the right hand end of this cable as well.

When you are done, you should have two cables with a mark for each twisted end on either of the cables but never on both.

Take the cables away from the chess board.

Step 4: Soldering

Cut some of the insulation off the cable where you have marked it just on one side of the cable. Cut the marks out with spaces between 3mm and 5mm long.

Cut some of the insulation away from the end of the cable that you marked.

Add solder to each spot that you exposed.

Add solder to every end of twisted wire, all over the whole twist. That will help it from unwinding in the future as well as make it easier to join the cable to the twists.

Find any old circuit board and steal some resistors out of it. They are the ones that are like long blobs on the wire with cute coloured lines around them. If you are not sure what they look like, look for images on the net, they have a pretty generic style. I got some brown, blue and green ones, but I don't know what the colours mean if anything.

Solder the resistors together in a row.

Step 5: Solder on the Rails

Lay the cable back where it was when you marked it and solder the twisted ends onto the blobs of solder that you put on the cable.

Try and keep the first cable hard up against the board on the under side of the twisted ends.

Lay the other cable on top of the twisted ends and hard up against the board. Solder it to the remaining twisted ends.

If the two ends of the cable match up, cut one about 15mm shorter than the other one and put some solder on the end again. oops. This is so that the two cables won't touch and short out. (Shorting out is where the electricity can travel from one cable to the other because they are touching with nothing good between them.)

Step 6: Using an Old Mobile Phone Charger

Get an old mobile phone charger that plugs into the wall and cut off the end that you plug into your phone. You will notice that the cable from the charger is made out of two wires. Split them apart for about 5cm.

Cut one end about 25mm shorter than the other. It does not matter which end. Strip some of the insulation back like about 3mm and put solder on the ends.

Solder your string of resistors to the shorter bit of the cable.

I am not sure if there is much difference between chargers but you want something that is between around 5 and 9 volts. If you look closely on the charger it will have a number followed by a V. That is the number to look for.

Step 7: Adding Power and Putting in Some LEDs

Use a peg or something to hold the end of the wire from the phone charger without resistors on it to the shorter end of the cable on the board.

Plug the mobile phone charger in. Hold onto a bit of the cable that has solder on it that is attached to the charger by a peg and then use the back of a finger to touch the other wire from the charger. It really, really should not hurt you, but just in case there is something very wrong with your charger you will find out with the back of your hand and not end up gripping it and getting hurt.

Now get one of your LEDs and bend the legs out flat.

Touch the remaining mobile phone cable, the one with the resistors on it, onto the remaining cable on the board. The one without the peg on it. If it sparks or anything you have done something wrong and there is a short. If it does not spark, that does not mean there is no short though.

While the charger is connected to the board touch the LED with the bent legs two wires that go over the same row so that only one LED leg touches each wire. Each leg of the LED must only tough its own wire.

If it lights up, good. If it doesn't turn it around so that the legs touch the other wires instead. LEDs can tell if they are the right way round or not. I don't think it hurts them if they are the wrong way, they just don't light up.

Once it lights up, you know which way around it goes. Do not leave it on the board if it glows really bright and sort of a bit yellow looking. That will mean there is too much power. We will get to that.

Lay the LED on the table so you know which way around it goes. Which legs like which wires.

Do the same for 7 more LEDS so that you have four of each colour. 4 laid out on one side of the board and 4 on the other.

Step 8: Sticking LEDs Under the Wires.

Now that you know which way around the 8 LEDs go, stick them under the wires.

They should already have their legs sticking out sideways.

Turn off the power.

Tuck a leg under each wire and then slide the LED right to the edge of the board. Make sure that each LED is in its own row. I put mine on the two ends where the castles stand and two in the middle where the king and queen go.

One colour at one end and the other colour at the other end.

Plug the power back in and they should all be glowing. If they all glow a bit Yellow, quickly turn it off again.

Step 9: Choosing a Resistor

If you connected the phone cable wire with the resistors on it, disconnect it again.

With the power on and the 8 edge LEDs in place, touch the tip of the wire from the end resistor on the free cable on the board.

If the LEDs glow a bit yellow, you have too much power and you should add some more resistors. If you are getting a string of them, try some other colours.

If the LEDs glow too faintly try touching the join between the end resistor the next one on the cable. If it is still too faint, keep going back up the chain until they are bright but not yellow. If you get down to no resistors and it still isn't bright, you might need a different phone charger.

Note, you can loop the chain of resistors back around to the wire where they come from or a join to try different combinations. Just play around till it looks good.

Once you find a combination of resistors that seems good, try and tidy it up by just using them.


THE REASON FOR THE 8 LEDS ON THE EDGE:

I first did the board with No LEDS on the edge and when all the pieces were on it was fine. But when I got down to two or three pieces on the board, they started glowing a bit yellow which is bad.

So instead of leaving some pieces on the board all the time, I put some LEDs on the edge. The amount of power used by all 32 Pieces is not like 32 times more than the amount of power used by 1 piece. It is a bit weird. 32 Pieces glow just as bright as 8. 1 Piece on its own glows really bright and wrong looking.

Step 10: Putting LEDs in the Pieces.

Now that you have the LEDs in the edge, you can solder them in if you like. You can also leave the board on while you do all the pieces.

Get an LED and about 3mm down from the light, bend both of the legs over at right angles. Then spread the legs out so that they make a short T

Now lay the Led on the underside of the chess piece. You may have to remove the paper bottoms from the pieces if they were ever there.

Centre the LED in the chess piece and hold the legs flat to the base. Bend the legs up the sides of the chess piece.

Take the LED off the chess piece and bend the legs in a little bit more.

Now 'clip' the LED back on the chess piece and try it on the board.

If it does not light up, turn it around. If it still does not light up, try it somewhere else, and then fix the bit of the board that is not working. I had to do this where my soldering was bad.

If the piece is facing the wrong way when it lights up, turn the LED around in it.

Made sure you set the pieces up at their own ends so that they are facing the right way when lit.

Step 11: Glueing in the LEDs

I used some crystal clear araldyte.

Mix up the areldyte, just a little. Use a match to smear it onto the chess piece and the wire that goes up the outside edge.

DO NOT put any glue on the bottom of the chess pieces. If you do get some scrape it off and when it is dry scrape it again with a knife. Metal has to touch metal for it it work.

Once you have put glue on the legs on the outside of the chess pieces, place the piece on some scrap paper and push it down a little. Make sure the legs are pretty straight.

Step 12: Finished

Once the glue is all dried, you are finished.

If the pieces don't light up for some reason it is probably because you have a piece sitting across two wires on the board that it shouldn't. This makes a short and the power goes wrong.


If anyone knows an easier way of getting the right resistors, please let me know. If you can make it simple enough for me to understand and it will work with most of the phone charges, I will update these instructions.

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