Step 2: Materials and tools
All I actually bought for this project were the magnets - small, countersunk neodymium magnets from ebay.
The rest was made of material I already had stocked in my shed - scrap timber, bamboo skewers and a pair of dead ball-point pens.
Similarly, no specialist tools were required - a junior hacksaw with blades for wood and metal, a hot-glue gun, drill and my multi-tool.
Health and Safety
You'll be using hot things, sharp things and very whizzy things. Be careful.
Take particular care with neodymium magnets - they can nip painfully, and will shatter if allowed to fly together.