Maxwell's Spinning Top

Maxwell's Spinning Top

Maxwell's spinning top is a curious spinning device. It combines the physics of a spinning top and a gyroscope with friction to produce some interesting movements. When the top is spun the upper spike comes into contact with the wire spiral and by forced precession it follows she spiral as if by magic. It is named after James Clerk Maxwell's dynamical top which was developed in 1856.

How it works

The solid brass rotor has a spike below and another on above. The bottom spike fits into a dimple in the stainless steel support journal and the top spike points upwards into the upper wire spiral. The rotor can be spun by hand to produce the forced precession effect, but it is much more efficient when it is spun with a piece of string. The string is threaded through a small hole in the upper spike and wound around the spike. When pulled gently and steadily the rotor will start to spin and friction between the upper spike and wire spiral will cause the spike follow the wire spiral.

The top will follow the spiral all the way to the end and then almost magically wrap around to the other side of the wire and go back the way it came. It will follow the spiral in and out until it slows to a stop.

TIP: Try spinning the top clockwise and anti-clockwise. It will do something a little different as it passes the outer end of the spiral!

Main features:

• Solid brass rotor
• Kevlar pull string
• Demonstrates forced precession

Materials

• Stainless steel spikes and support journal
• Brass rotor
• Anodised aluminium base and support arm

Dimensions

• Base- 100mm diameter, 10mm thick (3.93" x 0.39")
• Rotor - 50mm diameter (1.97"")
• Overall height - 110mm (4.33")

Kit

The top is supplied as a self-assembly kit.

Instructions

Click the image below for PDF assembly, operation and maintenance instructions for this top.