I have a small wooden Burr/Altekruse puzzle comprised of 12 pieces. The pieces come in two shapes, as seen below. There are 8 of the lower left piece and 4 of the upper right piece. I can't remember how to put it back together, but the last time I did, I found the instructions online. I can't seem to find them anymore.
puzzle piece shapes

  • $\begingroup$ I can't imagine someone being able to solve this mentally / just using 2-D images... Perhaps someone who has a 3-D printer might have better luck. :) $\endgroup$ – KeyboardWielder Jun 3 '16 at 15:56
  • $\begingroup$ Well I'm pretty confident - it's just impossible to validate as I don't have the pieces, or a physics engine to simulate it by computer.... $\endgroup$ – Spacemonkey Jun 3 '16 at 16:03
  • $\begingroup$ @Spacemonkey I am trying to validate it...It's not easy when the pieces are smaller than my pinky finger. The image above is almost to scale, they are 4.5 cm in length and 1 cm on each side. $\endgroup$ – David Wilkins Jun 3 '16 at 16:20

Start with the 4 pieces in the upper right corner of your drawing:

Step 1

Insert two of the other pieces from the sides:

Step 2

Insert two further pieces from above:

Step 3

Repeat the last two steps on the upper half of the burr:

Step 4

  • 1
    $\begingroup$ Wow, great answer! I love the pictures! $\endgroup$ – Deusovi Aug 20 '16 at 18:42
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    $\begingroup$ It is likely that the 4 vertical pieces in this solution can a quarter turn to lock the other pieces in place. Their rod-like parts are likely to be rounded or thinner to allow this to happen. This puzzle also usually comes with a marble that is to be locked inside, and is called the Caged Ball Puzzle. The classic version of this puzzle has a different set of pieces, including some that are a combination of the two in the one shown here. $\endgroup$ – Jaap Scherphuis Aug 21 '16 at 8:20
  • $\begingroup$ @JaapScherphuis you are correct, unfortunately I haven't been able to find the time to create the render myself, but this answer is changed I will accept it. $\endgroup$ – David Wilkins Aug 24 '16 at 13:43
  • $\begingroup$ to be clearer, all 6 sides and corners of the finished 'box' are symmetrical $\endgroup$ – David Wilkins Aug 24 '16 at 13:45

just analyzing the shape, you can form 4 'corners' comprised of 3 pieces each.

Your lower left piece(A) should be used twice in a corner. If you leave the first(A) as it is in the picture, you want the second one to be rotated 90' into a standing position so that the right edge of the piece is now the base. and then rotated it 180' on it's new base. Slide it into the indent of the first piece, that should leave a straight narrow space allowing for the upper right piece(B). You now have a corner. Fit all pieces together to have your 4 corners (2 corners make a base of the square plus 2 standing sides)

Its a bit complicated to explain without a software that lets me easily draw in 3d...

hope it helps

EDIT:: This website seems like it has THE puzzle you have, you can try logging in or registering etc... for the solution, I didn't :P


  • $\begingroup$ I registered. The solution for that one shows 5 different parts, 2 of which do match the two for my puzzle. That's closer than I have been able to find, but still not it. $\endgroup$ – David Wilkins Jun 3 '16 at 16:41
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    $\begingroup$ Ok, your answer was almost correct. The A (as you labelled them) pieces are made to rotate. Don't know if it is 100 percent correct, but in the end all 4 of them are parallel. I agree that it is hard to explain without images, so I will do some CAD drawing this weekend to try to illustrate it, and if it indeed matches what you were describing, I will accept your answer. If it is drastically different, unless someone else posts it first, I will post it as an answer. $\endgroup$ – David Wilkins Jun 3 '16 at 17:04
  • $\begingroup$ If you are going to draw the solution definitely post it as your own answer! $\endgroup$ – Spacemonkey Jun 3 '16 at 17:35

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