Instructables
Picture of Make a Wooden Soma Cube
Make this 3D puzzle out of wood.
The Soma Cube was invented by Piet Hein in 1936 during a lecture on quantum mechanics conducted by Werner Heisenberg.

(taken from http://en.wikipedia.org/wiki/Soma_cube )

The cube is made from 27 cubelets formed into 7 pieces. I've used the naming convention used on wikipedia to make things easier to understand.


 
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Step 1: Tools and Methods

Picture of Tools and Methods
Basic hand tools are all that's needed.
  • hand saw.
  • mitre box to keep all the cuts square.
  • some sort of clamp.
  • A wood workers try-square to check all cuts.

Select a length of wood batten, oak for example, and make sure its square. My wood was 29mm square and 1 meter long, even though I only used about 820mm.
Instead of cutting 27 accurate 29mm sq cubelets, I cheated and used only 15 cuts to create 2 X 3 segment pieces, 8 X 2 segment pieces and 5 individual pieces.
Ideally all the wood grain should be jumbled up to make it harder to analyze the complete cube, but using my shortcut method this wouldn't have been possible so I'Il make fake saw cuts to simulate individual pieces.

Step 3: The Left screw and Right screw Tetracubes

Picture of The Left screw and Right screw Tetracubes
right screw.jpg
left screw.jpg

These two should mirror each other, otherwise its wrong. I used 2 x 2segments to create these ones, make them at the same time to get it right.

Step 4: The T Tetracube

A single piece joined to a 3 segment piece, again with fake saw cuts about 5mm in depth to simulate individual pieces.

Step 5: The S Tetracube

Picture of The S Tetracube
S cube.jpg
This is a simple one, two 2 segment pieces joined and fake saw cuts.

Step 6: The Branch Tetracube

This one is the trickiest to get lined up and square, start with the L tricube shape and when dry glue on the final single piece.
davidsona3 years ago
They sell inch and centimeter cubes made of wood and plastic at teacher supply stores. I bet I could pick some up and make this easily. (Not entirely confident in my cutting something square)
OK! OK! I finally got around to making one from teacher supplies. Believe it or not, it was easier than I thought. I used wooden 2cm cubes and wood glue. Even with the paint on the cube, the wood glue has stood up to a 4yr old. (Well, only one break after an entire night of whacking on the table. Easily fixed though!) The parts you see are the second project. It was also a great opportunity to practice counting and arithmetic skills with dd. Again, the cubes are great because you can find them at teacher supply stores easily. Even better, they're already the exact size you need!! Thank you so much for this 'ible. It has entertained 4yrs, 15yrs, and...well.... none of your business....adults. ;0) The cube fits together better than it appears in the pics. DD wanted to help so badly.
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pgd50003 years ago
I found a guide to make one of these in a magazine once, and i made it for fathers day
jedijaxson3 years ago
I made a lego one of these, but with different sections!
rimar20004 years ago
VOTED!
Novmama4 years ago
Interesting! I like it!
MrMike4 years ago
Not a "burr" puzzle; but I do like the "misdirection ques" that the false saw cuts provide. Also rather easy to build, and should look quite good using highly grained / polished wood. Thanks for the write up - another good use for some scrap oak to build a desk top "visitor annoyance" device.


Buzzsushi4 years ago
This looks sooo cool! and simple too! Ive been dying for something like this! Good timing too, I have no school tomorrow and I finished my homework today! Monday project time!
I did it! Some irregular squares cut from a 2$ piece of wood and hot glued with excess glue and It works. A nice coat of stain made it look professional too.
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petercd (author)  Buzzsushi4 years ago
wow that was fast, glad you liked it.

mmm... must be some sort of record here. Im sure I have a DIY patch for that. :)
Haha. Some kid in my math class spent the whole 52 minutes trying to figure it out. He never did.... He got sooo mad at me... This thing is really entertaining.
A caffeinated version of the Soma Cube is what I called Quadrominoes http://www.instructables.com/id/How-to-Make-Quadrominoes-or-Four-Cubed/ Basically, you double the Soma Cube then add two more pieces. You can make a 4x4x4 cube. Well, you can try.

For the ultra caffeinated puzzle addicts, I recommend making Pentominoes: http://www.instructables.com/id/How-to-Make-your-own-Pentominoes-from-Alphabet-Blo/  There are 2339 solutions for the 1 x 6 x 10  shape, not counting rotations and mirror images. Only for those who can make the Soma Cube in their sleep. 
Making-shapes.jpgHow-to-Make-your-own-Pentominoes-from-Alphabet-Blo.jpg
I might also make a more precise soma this weekend, the one I made was a little off...
Quadrominoes. Alright... Next weekend it is!
CoolKoon4 years ago
Interesting, I've seen a puzzle based on this "soma cube" in Hungary first (I'm from Slovakia). Then this summer I've been to Transylvania and a lot of souvenir shops have it there. So I bought one too. But that design's a bit different: the small cubes (all of the 27 pieces) are cut and connected with a rubber band to form these individual shapes. Then these shapes are connected with rubber bands too (although in a plane that is different from the plane the shape's in). This way only the cube can be assembled (I think) and only in a single way. No variations.
249074 years ago
I made two of these back in middle school shop class, though they didn't look as nice as yours. Thanks for posting this, Nice Instructable!
thepelton4 years ago
Oh wow! Soma! What a blast from the past! I had two sets about thirty years ago. Figured out you could make a modified cube from three sets, and used another guy's set to prove it. It would have been five by five by five, but it was missing all the corner cubes, so it ended up like a three by three cube with a one by three square on each face.
agent4 years ago
I go to an engineering school. We made these in our first level class. I never knew what they were really called! Congrats on such a great 'ible!
lilratanak4 years ago
"My wood was 29mm square and 1 meter long" lololoolol sry... but yeah this looks like a fun thing to make
salomon19964 years ago
this is OUSOME! im not sure if i have a have a set of plastic ones or not, but i still want to make a set! :P
dark sponge4 years ago
Look at the picture in step 1, IT'S TETRIS IN 3D!!! :D

Also, great Instructable!