These are some shots of the new SRSG I'm putting together for my 4" coil. It uses a 1800RPM 1/14HP synchronous motor from a Teletype machine. The disc is 6" diameter LE phenolic. The stationary electrode holders are 3/4" brass rod and the electrodes are 3/16" 2% Lanthanated Tungsten. The flying electrodes are brass acorn nuts.