What you need.

A 3D printer (or at least access to one).

3D files are posted here.

A Raspberry Pi.
At the minute project is set up for a Pi Zero W, but the same print can run a model 2 or 3 as well. Details to follow.

A 16G SD card (4G will work, but video eats up disk space!)

A Pi Camera.

A Pi Camera adapter (You may not need one of these, depending on configuration).

A Ball bearing (Fidget spinner size!). A 608 bearing is 22mm total diameter, 8mm bore and 7mm width.

Two stepper motors and boards.

Lots of m3 nuts and bolts. I got these

Battery or micro usb power supply.

Some soldering and might be some drilling (3mm drill).

Another machine to log into PiSkyScan with an sd card reader.