Rotary Spark Gap

Turn a bench top grinder in to a rotary spark gap.

Included CAD file for your editing pleasure..

Bolts Not Included (5mmx1.0)(8mmx1.25)(10x1.5)…

Hold sized for 5mm rod in spindle and 14 gauge solid (house) wire.

I used   https://www.printables.com/model/663448-bolts-nuts-washers-huge-base  

Still suggest you chase the threads with a tap to clean out and properly size and/or resize bolts.