Its all very much in the planning stages at the moment but im planning on building a machine to recycle polystyrene and I will need to create some sort of steel screw to fit down a barrel approx. 80mm dia. It will be a compacting screw so the threads will slowly get finer hence the need for it to go on a cnc I would guess. The screw would most likely need to be made from steel and aprox 650mm long.

Is there anyone here that would have the ability to do this on there machine?

many thanks