Check out vavuud website to look at real deal which you can purchase to support the application. They have tested their one in a wind tunnel so it's quite accurate.
Step 1: Shopping
2 sets of measuring spoons, I used 2 x 5ml spoons.
Neodymium magnets (the shinny strong ones) I got mine out of a fishing game
Small bearings, I got mine for a couple of dollars from a model shop, but you can get them from some toys as well.
A few old pens.
3.5mm headphone jack ( cheap headphone will work)
Other tools you need are scissors, soldering iron, small hack saw.