This instructable will cover creating a magnetic box with four neodymium magnets inside.
Step 1: Purchase Magnets
I used 4 1" by 1 3/4" cylinders from K&J Magnetics. You could get slightly bigger ones if you wanted to. An electromagnet could also be used instead of neodymium magnets if you wanted to be able to turn it on and off. This is useful because the magnets that I used are really strong. When they get stuck to things, it is really difficult to get them separated.
Step 2: Purchase a Cigar Box
Purchase a cigar box with the internal dimensions that fit the magnets that you want to buy. I got a 11" by 3" by 5 1/2" box. When you get it, take off the fastenings to prepare for staining.
Step 3: Stain Box (optional)
This is optional, but I decided to stain my box so it looked better. Make sure you are in a properly ventilated area.
Step 4: Glue Magnets Inside Box.
This is by far the most difficult step. The magnets have an attractive force of more than 400 pounds when they get stuck together. I drilled holes in a piece of scrap wood to keep them apart while the two part epoxy dried. Start by inserting the top 2 magnets with the north side up. You should be able to get them in the holes without them getting stuck together. For the bottom two, it is more difficult. I could not get them in the holes without them getting stuck to the ones above them, so I removed the front panel from the box and cut out the bottoms of the circles. The magnets will actually repel and try to flip over so that the south side is up. You will have to clamp them down while the glue is drying.
Step 5: Clamp Magnets
The magnets do not want to be where they are placed. They will flip over and stick to the magnet next to them if you are not always keeping them in place some how. If the magnets collide they could shatter or crush a finger, so be very careful.
Step 6: Glue the Front Back On
Once the front is glued back on, the box is complete. Magnetic objects will stick together around the box and behave in cool ways like the paperclips in the picture above that seem to follow the magnetic field lines.