so i have a coil with 2 insulating rubber pads ( 1 per side of the coil) a steel dish washer to sit on top of 1 rubber pad and a bolt to secure the whole lot through the disc on to a metal plate that will be earthed anyway. so the steel disc will be earthed through the frame and if i put another earth at the top i'm creating a shorted turn. Standard Range Toroidal Transformers- CM0750225- 750VA 230v to 2x25v that is good to know , i've been searching the forum for a thread that explained the construction but couldn't find it . by the way is my understanding of how the coil is assembled correct or am i assuming the assembly incorrectly?