Motorised CD Wimshurst Machine

2 CD blanks, motors from computer case fans (fan blades removed.) Polycarbonate chassis.

Sectors were originally plain aluminium tape. This was severely damaged by the copper neutralising brushes after only a few minutes of running. Brass buttons (drawing pin heads) were added to the sectors and the aluminium varnished over.

Original soft copper brushes were destroyed in seconds by the brass buttons.

Heavy duty neutraliser "brushes" are small damped springs. Undamped and they resonate at some speeds and 'disconnect'. Disk speed is reduced by the pressure of the springs but long term reliable operation is assured.

The video and audio are slightly out of sync'.

Camera missed loads of the sparks - listen to the audio - the discharges were upsetting the microphone.

Another view showing the threaded columns allowing adjustment of disk alignment and spacing.

It is reluctant to start if the disk spacing is more than about 1.5mm.

Too close disk spacing reduces output due to (electrostatic) drag between the disks. Optimum is about 1mm.

Maximum spark so far is 25mm.

10 second exposure of the machine in what should be an overload condition - spark gap is set to approx' 70mm.

Discharges from the sectors do not breach the neutraliser...collector gap!

Insufficient output current to overcome the losses?