How to Make a Difficult Lego Puzzle




Have you ever wanted to make a difficult puzzle out of LEGO without all the hassle of designing and complex building? If so, then this project is for you!

There is a Lego Digital Design file at the bottom of this page for this project.

You will need:

Lots of LEGO pieces.

Step 1: Creating the Base

The base is probably the easiest part. I used three 4x12 plates put side-by-side to make a 12x12 square. Yours could be any size.

Step 2: Building the First Layer

The first layer must have a depth of at least three pieces to let the mechanism fit. This layer has no special pieces in it, so it should be easy to construct.

Step 3: Building the Second Layer

This layer is like the first, except with one minor addition. Four Technic 1x2 pieces were added to the inside edges, two on each side. The picture explains all.

Step 4: The Final Layer

This layer is built exactly the same as the first, so no explanation is needed.

Step 5: The Piece

Building the piece is easy. The picture will explain how to make it.

Step 6: The Mechanism

The mechanism is made up of two 2M axles. They fit into the holes of the base, as shown in the images below. The axles will slide into the piece, therefore locking it in.

Step 7: How to Set Up the Puzzle

Put the cross beams in the holes in the base. Put the piece in the base, making sure the holes are on the right sides. Put it in until only the first layer and plate are showing. Tilt the base until you hear the cross beams moving, and the puzzle is ready to go. This puzzle is very difficult to solve, because if you try to tilt one of the cross beams out of the piece, the other one will slide in. The best way to solve the puzzle is to hold it above a flat surface, and to spin in midair as you would spin a coin. Centrifugal force will ace on the pieces, causing them to move outward at the same time. The piece will also sink into the puzzle, showing that it can be removed. Have fun showing it to others!



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    24 Discussions


    2 years ago

    I had one of these years ago but it was not made from Lego. I have to make one as soon as I can find all the pieces. Thanks for a great idea!


    5 years ago on Introduction

    I didn't have any of those little x pieces, so I used the stick part of a Q-tip, haha.


    5 years ago on Introduction

    I blew my familys' minds with this puzzle. Pretty fun :)


    6 years ago on Introduction

    ooooooooooooooh my goodness i love this puzzle!!! it's really fun to show it to your friends and see the look on their faces as they try to figure it out!

    I loved this project so I stayed up a extra hours last night digging through my sons' Lego box to build it with 4 axles. I ran into a problem with solving it, though, & came up with a solution... when I solved the puzzle, the tight fit between the inner-block & the recess doesn't allow air to easily escape so the inner-block can drop.
    So, I rebuilt the bottom layer of the base to include 3 Technic-holes (vents) on two sides & it works much better... spin the puzzle & the center block will more pleasingly clunk into the bottom of the recess.
    I also lined the bottom of the recess with flat-topped strips to prevent inadvertently locking the inner-block into the recess...

    Very nice, project!

    Thanks for the idea! I made this 14x14, 4 bricks high with a 6x6 center block. I did the sides red white and blue striped and used two pegs just like yours. I made a small hidden 2x2 brick that is pressed into one of the corners to use as a "tool" for pulling up the center 6x6 block when it's unlocked. The 2x2 tool is just a stack of (2) 2x2 plates and (1) 2x2 tile, and blends in with the stripping colors of the side, making it invisible to the untrained eye. We brought the puzzle to our family Christmas party tonight and everyone had fun trying to figure it out, until my 6 year old son showed them how to solve it. we also added a small drawer in the 6x6 block that holds some small decorated tiles, schematics, a gauge and some other pieces of interest. You open the drawer by taking one of the locking cross pieces and pushing it into the cross slotted 1x2 brick. Here is a little photo gallery of my build ->


    7 years ago on Introduction

    geat instructables! i think it could be slightly better but it is still good
    you could do it with all same color bricks and put a pin on all 4 side insted of only 2

    St Jimmy

    8 years ago on Introduction

    If you made more than one first layer, and perhaps a stopper piece to stop the top falling in, you could use this as a safe, although maybe not a very secure one

    2 replies

    I seem to remember mentioning it not being secure? Although this principle would apply even to a puzzle made of solid steel, so I guess if the thief isn't particularly intelligent it would work...

    made a modified version too, its more of a challenge, with need of usind a key sort of thing to move a bar so you can pull the inside box out. thats for the idea


    8 years ago on Introduction

    Nice puzzle! I made a modified version of it- the removable part is now a case made out of clear lego elements. I'm going to put something inside it and give it to my brother for Xmas. Thanks for giving me the idea!