Quote Originally Posted by Jonathan View Post

Bit of a struggle to twiddle the wires I'm using to be honest
You won't do much of a lap if your mains lead is only that long...

Having heard what the end product is going to do, I would go back to the milling machine/boring bar/boring head setup if I were doing it in my own workshop. Clamp the work to an angle plate (tapped holes into the back of the work?), get a tool rotating with the right radius (I would use my boring head with the tool sticking out the side) and feed very slowly down. Slow spindle speed!