I built mine a couple years ago with these exact same plans. One thing I have learned is that you cannot put the two ends of the coil close together (220v coil). The photos seem to show only an inch or so- put them farther apart and be sure the insulation between is intact. If you don't, when you get it up to 1900 or so, you may hear and see this Whooshing flash and smoke when the ends short out and burn up an element - yea I peed myself a little bit..... I ended up spreading mine out about 4 inches (had to move them to the side) and covered them both with high temp satanite. Since then, I've had no more problems.