Okay, first we need to describe the puzzle; It's about a 4,000 years old design. It's very simple ... two exact halves of a 3-sided pyramid. Sounds easy? Well it's a brain teaser for your friends to assemble the two pieces into a pyramid. This Instructable is my challenge for you to see what all materials you can use for making these puzzle pieces using laser cutting.
The 40W laser prize here is a perfect home model for making soft plastic toys ... so first you need to find a suitable material (NOT PVC, NOT Lexan, NOT Stone etc... for various reasons of poisoning yourself and viewing friends 'n family to the fact that 40W can't cut into stone very well.) But what about a block of acrylic? That might work if the acrylic isn't too thick ... or maybe just using a chunk of Styrofoam packing to reshape into your puzzle pieces (near zero materials cost!) ... the cost is just a few calories of energy you use to cut it into small enough blocks to fit into your laser cutter/engraver.
Okay, lets get down to the meat of this Instructable ... Lets make a 4,000 year old Pyramid Puzzle piece.
Step 1: Selecting the proper size to cut ...
The idea is that the length of one side of the pyramid becomes the maximum depth of the laser cutting required to make these puzzle pieces. My experience with a 45W laser tells me I can easily slice through 60mm of Styrofoam so I'll stick to my original dimensions to keep this Instructable easier to modify for your own pleasures.
So the length of one side of the pyramid is 60mm ... then the center square of one half of that is exactly that 1/2 or 30mm x 30mm
The height from the bottom of the material block to the outer edge of the pyramid is 20mm ... that is from the center of the pyramid to the outer edge of a corner is 20mm. You'll see this more clearly in the next step.
This tells us that the block of material needed to make this puzzle piece needs to be something greater than 60mm x 30mm with a flat bottom and at least one very important flat side to sit on the laser cutter cutting bed.
Now we start with our first of two cuts (two cut sketches you make yourself) ... the two ends of our puzzle piece. You can see that in the 3rd image labled PyramidPuzzle-02 so now it's your turn to sketch that cut out in your lasers design program (CorelDraw, Adobe Illustrator ...)
Then place the material into the laser cutter and make the two cuts. Keeping the left over material still in place on the side that has the very important flat surface ... because that's used for the next cut!