The Turn Of The Century Electrotherapy Museum

Micrometer Spark Gap for Tesla Coils
(When 1/1000th of an inch accuracy isn't enough)

10,000th of an inch and beyond!

Brass, Phosphor Bronze, Tungsten, and Hardened Chromed Steel!

Brass Barrel, 1/2" Ball Bearing, Spring, Tungsten Contact, 5/16-40 Conical Adjusting Screw, Bearing Contact Mount, End Pieces

Several variations, one with theoretical 1/1,000,000th of an inch accuracy (.000001")

Concept Rendering

See-Through View

Note position of cone with respect to ball bearing

Cone is now raised and ball is retracted

Cross Section