Sparky Projects | Making RSG Discs @sparkyprojects | Uploaded June 2016 | Updated October 2024, 12 hours ago.
Getting a Rotary Spark gap made without it wobbling, and balancing it can be tricky, this is something for total novices with limited tools.
It's often best to balance the disc on the motor you are going to use, so why not use it as the lathe.