Introduction: Custom Acrylic Chess Board

I've always had a soft side towards chess sets.  I've never been particularly good at chess (I know how the pieces move and I know when I'm about to be destroyed, but that's about it).  I have, however, always enjoyed the artistry and design possibilities inherit in a good chess set.  It was The Shawshank Redemption that made me realize that you could make a chess set out of just about anything, and it was a month or so ago when I realized that I wanted a chess set of my own design.  Acrylic (also known as plexiglass) would be my medium and a laser cutter (generously provided for my use by MIT) would be my weapon.

The board is three layers of acrylic thick, the pieces are between 14 and 27 layers thick, and in the end you'll have a sturdy, scratch-free, and totally hand-made (laser made?) chess set!

This Instructable will walk you through

a)  What materials I used and where to get them for the best price
b)  How I went about designing the board and pieces
c)  The assembly process

and throughout the Instructable will be, what turned out to be vital, tidbits of information that, through trial and error, I've figured out so you don't have to.  I was fortunate enough to have access to a laser so I could make multiple cuts and try different approaches.  But that's not always possible (especially if you're ordering laser cut parts online), so my aim is to provide you with the information you'll need if you order your parts online.

Step 1: What You'll Need

Material (~$90 with shipping)
2 Acrylic Sheets (for the colored squares)  - 12" x 12" x 0.236" - McMaster
2 Acrylic Sheets (for the pieces) - 12" x 24" x 0.118" - McMaster
1 Acrylic Sheet (for the trim) - 12" x 24" x 0.246" - McMaster
1 Acrylic Sheet (for the bottom plate) - 17" x 17" x 0.125" - TAP Plastics
1 Scratch Resistant Acrylic Sheet (for the top plate) - 17" x 17" x 0.125" - TAP Plastics
2 Acrylic Rods (for the pieces) - 0.125" diameter, 6' long - McMaster #8531K11
1 Box of Screws (to screw board together) - 6-32, 0.5" long - McMaster #92949A148
Rubber feet (for bottom of board) - McMaster #95495K66

6-32 Tap - McMaster #8321A63
#36 Drill Bit - McMaster #30585A49
Allen Key - 5/64" - McMaster #7122A55
TAP Acrylic Cement (smaller can) - TAP Plastics
Hypo Applicator (for acrylic cement) - BD-25/2 - TAP Plastics

Cotton Archival Gloves (available on McMaster)
Microfiber Cloth
Materials for Pegboard (detailed later in Step Five)

Step 2: Design: Board

Big block of text, I'm sorry, but read it, it's definitely useful.  This isn't just a step-by-step thing, you'll need a "whole-istic" understanding of what's going on.

When designing the board I wanted to avoid using adhesive.  I was afraid that adhesive would make any clear pieces look bad (cloudy, bubbly, etc) and there's something to be said for having a board that can be taken apart and resembled in case it needs to be cleaned or you want to swap out a color ;)

The board is composed of three different layers.  The top and bottom layers consist of a single sheet of clear acrylic each.  The top layer is scratch resistant, the bottom need not be.  Each layer is designed in SolidWorks or in CorelDraw, whichever you prefer.  

As you can see in the first image, the middle layer consists of individual squares (only three are shown), enclosed on four sides by trim pieces (only one shown).  Each piece of trim has four holes (one at either end and two in the middle) that correspond to holes along the edges of the top and bottom plates.  The middle layer is sandwiched between the top and bottom layers and clamped together using screws.  The screws pass through the top and middle layers and screw into the tapped bottom layer.

I'll leave hole placement up to you.  You can space them however you like, just remember that the trim may bow in or out in the middle if there aren't any screws.

The second image shows the dimensions of each individual piece.  One thing you may notice is that 8 squares, 1.875" wide, plus the two pieces of 0.5" wide trim, doesn't equal 16".  Welcome to the wonderful world of laser kerf.  

Kerf = the thickness of the laser's cut.  Ordinarily this doesn't matter too much, it's usually a very narrow cut, but when compounded across eight squares (two cuts per square, one on each side), it adds up.  Without the extra 0.03" inches of width on each trim piece (which were ordinarily 0.5" wide), the squares rattle around inside the chess board.

The bottom layer's holes will need to be tapped.  You can use a drill and the 6-32 tap to do it, but I'd recommend against using the laser to create the holes.  There's just enough variability in the laser that it may make the holes a bit too large or small which could be bad for the tap or create threads that are too shallow.  INSTEAD, use the laser to make 0.05" diameter pilot holes for the bottom layer, then drill those using the #36 drill bit.  THEN, put the tap into the drill and tap each of the holes.  

The tap will get hot over time and will melt the acrylic a bit, you'll want to cool it after about four holes.  Compressed air or water should do the trick.

Since the top layer and trim pieces have clearance holes that don't have the tolerance requirements that the bottom holes do, go ahead and just laser holes that are 0.144" diameter.

Decoration?  On the top layer you can etch and engrave anything you'd like.  I chose the MIT seal, homage to the laser cutter they let me use.  Word of warning, engraving is OPAQUE.  You cannot see the squares under an engraving, so avoid large blocks of etching.  I recommend flipping the image horizontally and engraving on the underside of the top layer, that'll make the top nice and smooth while still shining the etching through.

Step 3: Design: Pieces

The chess pieces are made from stacked pieces of acrylic that sweep the outlines of the various pieces.  Picture 1 shows you a king.

I used SolidWorks to design my pieces.  It's long tedious work, easily the most difficult and unappealing part of the project, but the pieces look pretty sweet when they're all said and done.

Step one is to rough out some dimensions.  I checked all over the Internet for regulation sizes and ratios for the pieces.  In general it's a bit nebulous, always ranges of values, but here's what I ended up using:

Height ratios for King:Queen:Bishop:Knight:Rook:Pawn are 27:25:25:21:18:14.  I know what you're thinking, Bishops shouldn't be the same height as the Queen!  Well, you're right, but I think it looks good this way, but how you do it is totally up to you.

Each piece is comprised of stacked rings.  Picture 2 shows that each ring has a 0.125" inner diameter.  The outer diameter will vary from ring to ring.  I use the distance between inner radius and outer radius to define each ring's size.  The inner hole is for the rings to thread over the 0.125" diameter acrylic rods, holding them all together and in line.  

How do you actually design a piece though?  Check out Picture 3, it's a snapshot of the type of sketch you should make in SolidWorks.  This particular drawing is for the same king that you see in Picture 1.  It shows the cross section of the king with its farthest left vertical line indicating the center of the piece.  The 0.0625" dimension is the inside radius of each ring.  Each of the far right dimensions corresponds to the defining dimension of picture two.

Don't add those right dimensions right away.  Instead, leave those lines unconstrained in the horizontal direction.  Define everything else, but leave those right hand lines unconstrained,  Then, just drag them left and right until you are happy with what you see.  Exit the sketch, revolve around your far left line, and admire your handiwork.  If you like it, great!  Add dimensions, round them off to the thousands place, and move on to your next piece.  If your design needs tweaking, drag around the edges a bit more until you get what you want.

 The knight is a bit special and your opportunity to get creative.  It's not radially symmetric so it will need two central rods.  You can do the sketch in a similar fashion except you'll be dragging bars on the left and the right.  Picture 4 shows you how I accomplished it.

The rook is also a bit of a special case, it has a fancy top to make the top of a castle.  You'll need to use little spokes.  Check out the last image, it'll show you what I used.

But wait! You're just getting started! Doing this is just the design part, figuring out the dimensions for each ring. Now, bust out Excel, and record all of them.

The top and bottom rings of each piece work better if the inside diameter is a a bit smaller, 0.12" should do it, to create a snap fit on the central rod.

Your next step is to create an individual part for every single ring. That's right, in the end you'll have over a hundred files, each a ring.  I suggest a folder for each piece and a logical naming scheme.  I named each part using the first letter of each piece and the number of the ring (from the bottom of the piece).  For example, B_2 is the 2nd ring from the bottom of the Bishop.  Ki_15 is the fifteenth ring from the bottom of the King.  

Great!  Now you have a ton of individual rings!  And rectangles (for the knights)!

Now, drop them all into a drawing file, scaled one to one, and make sure they all fit into a 12" x 24" sheet because that's what you've got to cut them out of.  Also, make sure the pieces are in order, because if you can't remember which ring is which, well, you're hopelessly lost and sad.  Picture 5 is what my drawing file looks like.

Just for grins and giggles, I'll give you the numbers I used for my pieces, in case you like them so much you want to have a chess set exactly like mine.  It's all in the attached Excel spreadsheet.

Step 4: Assembly: Board

Alright, hard part's done, let's do this!!!

Here are some lovely little power settings I used for my parts.  I used a Universal Laser 6.6, 60W (Picture 1).

Cut 0.236" thick acrylic:  100% Power, 2% Speed
Cut 0.118" thick acrylic: 100% Power, 5% Speed
Engrave any acrylic:  80% Power, 100% Speed


I mean that.

You'll want to remove the top sheets for all of the acrylic sheets (squares, trim, etc) so you don't have to peel all of them off individually when everything is cut out.  I made this mistake the first time and my fingers hurt a ton by the time I was done.

Great, your parts are now cut out!  WOOOOOOO!  Picture 2 shows all the squares and trim laid out.  Note the protective paper.  I should have taken some of that off earlier :(

Picture 3 shows the holes in the bottom layer.  These require a bit of work.  You may have to punch out some plugs that get stuck in there (like the right hole).  Next, drill them out with the #36 drill bit and then tap them with a 6-32 tap.  The cross section looks pretty slick, you can see the threads.

Picture 6, alright, rip off the protective paper, it's go time.

Lay down the bottom layer.  Lay the trim around the edges, then place the individual squares in.  You may want to use archival gloves to avoid smudging things.  Now lay the top layer on.  Take your allen wrench, drop screws through the top layer, through the middle layer, and then thread them into the bottom layer.  Don't overtighten, you'll strip out the threads in the bottom layer.

Put a little rubber foot on the bottom between each pair of two screws.  Voila!  BOARD (Last Picture)!

Step 5: Assembly: Pieces

Oh boy, here we go, this is when things get fun.

Take the top layer of paper off the 12" x 24" sheet and cut out your piece rings.  When you've cut your pieces (should take around a half hour), you'll need to remove them from the laser cutter somehow.  The first time I did it I threaded each piece onto a red wire (Picture 1).  This isn't for a final assembly, this is just to get everything off the bed of the laser for final assembly elsewhere.  

I also tried another approach for temporarily holding the rings in order and transporting them.  I built a pegboard out of a piece of wood and some sections of 0.120" diameter steel rods.  You can see some yellow and green pieces stored on the pegs in Picture 2.  You'll want to file the ends of the rods so the pieces don't get caught on burs.

Ok, time to do some final piece assembly.  Cut acrylic rods to the length of the pieces.  Snap the bottom ring onto the acrylic rod.  Drop all the other rings down onto it.  Snap the top ring on.

The snap fits on the top and bottom rings should hold the piece together temporarily, at least enough to allow you to use the adhesive to "seal" the deal.  *snicker*

Drop several drops of adhesive on the top of the piece and let the capillary action suck the adhesive down into the hole with the peg, gluing the top disc to the rod.  Flip the piece over and do the same thing with the bottom of the piece.  Clip of any extra rod sticking out.  Repeat for all the pieces.

Step 6: Finis! (and a Couple of Notes)

What?  You mean after peeling paper off of 64 squares, over a hundred little rings, cutting 32 rods to length, gluing, tapping, screwing, polishing, and LASERING(!), you have your very own chess set?


And now, for all those little notes I want to get off my chest:
  1. I ended up not being a huge fan of the clear pieces.  You can see the rod, which I'm not too sure about.  The adhesive also kind of clouds the clear pieces.
  2. I hate pealing paper off, but I tried several ways to cut the rings for the pieces without leaving the paper on and just couldn't do it.  I tried just taking it off (the acrylic blackens), I tried putting aluminum under the sheet to prevent blackening (heat reflects back into acrylic, destroying all tolerances and creating a super-strong smelling liquid that would probably kill you), and I tried using butcher paper under it (which stained the pieces yellowish).  Suggestions welcome, but for now, peeling off paper from tons of pieces is where I'm at.
  3. Leave the top piece's paper on, facing up, when gluing.  It lets glue seep into the hole but prevents it from staining the top disc.
  4. You can leave the paper on between discs for the black pieces, it stays hidden (shhhhh)!
  5. The screws are a bit too long, sticking out on the bottom a bit, but the rubber feet make it a non-issue.
  6. Chess is awesome!
So that's that!  Leave comments, I'll answer, and I hope you end up with a marvelous chess set of your very own!
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