Geometry or Formuls to construct a circle to three entities.

[Doddy]

This was my today project, from circuit diagram to pcb. It is a logic indicator circuit (Hi-Lo_Pulse) using a 4011.


Cheers,

Rob-T

Thread-creep: I'm curious - I've had mixed results with isolation routing in the past (to the point that I refuse to entertain the idea any more and unlikely to change my mind) - but you go for complete copper removal... what cutting bits do you use/find useful for this?