In this tutorial I am going to show you, how to make your own Rubik USB Flash Drive

You can see the finished product in the following video:

Step 1: What You Need

material:

a very small usb flash drive (e.g. EagleTec USB Nano Flash Drive or Delock USB Nano Memory stick)
(e.g. from http://usb.brando.com/eagletec-usb-nano-flash-drive_p00892c041d15.html)
a corner piece of a Rubik's Cube
an edge piece of a Rubik's Cube
self-hardening synthetic clay (I used “Apoxie® Sculpt”)
a lip balm stick (I used a ”Labello“)
a small screw (I got mine out of an old dvd player, it's about ~0.6 cm high)
a washer Ø 1.2 cm
Tiles or stickers (e.g. from cubesmith.com)

tools:

a Dremel (Felt Polishing Wheel, different grinding stones, precision drills) (you don't have to get a very expensive one, I got mine pretty cheap on ebay)
a small slotted screwdriver (to apply the clay)
sandpaper (400, 800, 1000)
a black permanent marker
a small saw (I used one for metal)
a box cutter

Step 2: Modify the Flash Drive

First cut off the plastic casing of the flash drive (please don't cut into your fingers, nor any important part of the flash drive!)
Then apply the clay in order to secure the parts, make sure not to get any inside off the metal part.
While the clay is drying (it takes minimum 3h if you would like to grain it, you should let it dry over night) you can manipulate the pieces of your cube. I took the spare pieces from a Siamese Cube which I made earlier.

Step 3: Modify the Cube Pieces

Use the edge piece as the top and corner piece as the bottom part and get rid of the inside as shown in the picture. Make sure to leave two pins (“circled” in blue) in the middle of the edge piece, which will later be used as a guard rail (don't worry about the height yet). In order to drill the hole in the middle measure the stick and mark the shape. It doesn't have to be to neat, because you can later fix it with the modelling clay.

EDIT: Some people asked me about this step, I hope that the second picture is better (yeah I know it looks pretty gross ;-)). As you can see I did not drill the whole inside of the edge piece away (to make sure that the drive slides up in the right way). The grey stuff is Apoxie Sculpt I used it to try to get a better result, but it is not necessary.

Step 4: Modify the Lip Balm Stick

Now we will manipulate the lip balm stick. Depending on the brand, yours might be very different from mine, but just manipulate it accordingly.
First get rid of the lip balm and pull very hard on the top and the bottom, so that the bottom piece comes off.
Now saw off the bottom and the top, as shown in the picture. Be very careful not to saw off to much and not to cut into the sliding part (we will later adjust the height).

Go back to your cube pieces and grain off enough from the inside, to be able to smoothly turn the stick in the bottom piece and to tightly fit it into the top piece (I know it seems impossible but with some patience you will be able to manage it. Just remember to let the Dremel cool off, else you might burn some ugly holes in your parts. If you do, simply fix them with the modelling clay).

Step 5: Step 4 (I Know a Very Creative Title ;-))

Now we are going back to the usb flash drive and modify the pieces as shown in the picture.

You might be able to find a better fitting washer, but the hole in mine was to big, so I had to make it smaller (yes, I love Apoxie® Sculpt ;-)). I used a small slotted screwdriver to apply the clay (water helps, to prevent the clay from sticking on it).

To save time go back to your cube pieces and fix the hole in order to get a perfect rectangular shape. Now smooth out the edges in the bottom part as shown in the picture.

After letting all the pieces dry over night, you should try to make them fit exactly. In order to do so place the washer into part 1 (check out the picture for the numbers), the usb flash drive on top of it, reassemble the lip balm stick and put it into the edge piece. Now slide it up and make sure, that you would be able to use the usb flash drive. If it doesn't slide up high enough, check out the following reasons:
1. Your guarding rail (the two pins in the edge piece) is two long, simply grain of a bit from the top of the pins and try again.
2. Part 2 is to short, simply apply a bit more Apoxie® Sculpt either on the washer or on the parts I marked with green circles.
3. The lip balm stick doesn't fit right into the piece, you have to drain of more from the inner sides.

After checking on these points assemble the pieces and try again.

Step 6: Assemble the Pieces

If everything fits you need to apply them in the following way:

Put the screw through the hole of the washer and glue the usb flash drive on top of it. Take good care, that the screw is still able to turn smoothly. As you can see in the picture, I applied an extra layer of Apoxie® Sculpt on the back left side to have a better result in sliding it up.

Now glue the screw to the inside of the hole of part 2. Make sure, that the usb flash drive is turnable.

Put your finished product back into the lip balm stick and then into the edge piece. Apply the bottom part and make sure, that there is no hole between the pieces. If there is, take the stick back out and use a box cutter to shorten the top of the stick (graining didn't work out to well for me).

Paint the part off the stick that might shine through with a black permanent marker and use the Felt Polishing Wheel from your Dremel to get rid of the extra paint.

Reassemble all the pieces and make sure, that your are able to smoothly turn the stick up and down. Now fix the side of the edge piece, as shown in the picture with the modelling clay.

Glue the part I marked with orange in the picture to the bottom of the corner piece (while the stick is turned all the way up).

Step 7: Finishing Touches

Let it dry again and apply the stickers (check out a real cube to do it in the right way). To prevent the usb flash drive from going down to far, turn the stick up (until it's not possible any more) and twist the cube in an angle of 270 degree. Now pull the pieces apart and mark the position of the two pins of part 1 and put a very thin layer of modelling clay inside of the thread on your marked position (take a look at the picture).

Let it dry, put the pieces back together and have fun with your self made Rubik Cube USB Stick.