In this Instructable I am going to show you how to turn a regular 3x3x3 Rubik's Cube into a Rubik's Cube-Octahedron. This is basically a 3x3 shape mod however it adds another level of difficulty to the already frustrating puzzle :)

Step 1: Materials

3x3x3 Rubik's Cube
Sharpie (Permanent Marker)
Ruler
Exacto Knife
Milliput (Black is best if available however any is fine)
Dremel with cut off wheel or Hacksaw
Sandpaper (I used 220 and 400 grit)
Black Spray Paint

Step 2: Drawing the Shape and Removing the Material

To start off on one face find the center of all the edges and make a mark with your sharpie then connect these marks up diagonally using your ruler, you should now be left with a diamond shape on the face. Repeat this step for the remaining five faces on the cube.

Next take your dremel and cut along the lines shown in the image (the blue lines) sorry I do not have an image of this although you are basically removing most of the corner piece and half of each edge piece of the puzzle to leave a flat triangle.

Step 3: Disassembling Your Rubik's Cube

Now dissemble your Rubik's Cube to do this you;

Turn your top layer 45 degrees
Pry out one of the edges
Remove all the remaining pieces

You will now be left with a pile of pieces I think it is best so sort them into corners and edges, leaving you with a pile of corner pieces, a pile of edge pieces and your core.

Step 4: Filling the Pieces

With your corner and edge pieces sorted into two different piles you will now have to remove the stickers from your puzzle using your exacto knife.

Now mix up equal parts of your Milliput epoxy. If you have access to black Milliput I suggest you use it, unless of course your planing on making a white puzzle. As you can see I have used standard which is a yellow color, however it makes no difference it just may take a few extra cotes of spray paint.

Take your Milliput and fill in your corner and edge pieces you should overfill the pieces and leave the Milliput to dry as instructed on the packaging (I left mine overnight)

Once dry sand the pieces flat as shown in the image above I used a belt sander to do this quickly however you could use your dremel with a sanding bit attached or even just by hand with a piece of sandpaper.

Step 5: Reassemble Your Puzzle and Spray Paint Black

Sorry I do not have images showing the puzzle I had being been working on reassembled and painted however it will be assembled the same as any other 3x3x3 Rubik's cube.

To reassemble your puzzle;

Take your core and insert four edge pieces all adjacent to one another
Flip the cube upside down and add the corners
Add another four edge pieces above the corners
When assembling the top layer add one edge piece
Add two corner pieces to each side of this edge piece followed by two more corner pieces
Turn your top layer 45 degrees and snap in the last edge piece

Once your puzzle has been reassembled use the 220 and 400 grit sandpaper to make sure the entire cube is smooth to the touch, then spray paint it black. I did three coats of paint lightly sanding with the 400 grit sandpaper in between each coat.

The last two images is how your cube should look after; disassembling the puzzle, removing the stickers, filling and sanding the pieces, reassembling the puzzle and spraying it black.

Step 6: Stickering the Puzzle

Ok so when I purchased the stickers for this puzzle I got them from a website called "cubesmith.com" where the stickers came pre-cut, unfortunately cubesmith is now shut down. You could search the internet for "3x3 cube octahedron stickers" and maybe you'll find some, another option would be to purchase vinyl sticker sheets from somewhere like "www.oliverstickers.com" or even Ebay or Amazon and cut the stickers yourself by hand, if you do go for the vinyl sheets you will need 14 different colors (6 faces and 8 corners).

I used the exacto knife to help with the placement of my stickers I found it was easier to apply them this way.

Step 7: Finished Puzzle

Your now finished and have a completed 3x3x3 cube-octahedron Puzzle made from a regular 3x3x3 Rubik's Cube.

I want to apologise that I did not have images of some processes however I hope the images I have provided and the written steps are enough to guide you through the process of creating your own.

Finally the only thing left to ask is can you solve it?

Thanks for reading :)

Introduction: How to Make a Rubik's Cube-Octahedron