Holroyd Precision has produced
what is thought to be the biggest
CNC helical profile milling system
ever made, at a cost of £2.5m, on
behalf of a major Chinese compressor
manufacturer.

The machine is to be used for the
roughing and finishing of outsize
screw compressor rotors for use in the
gas processing industry.Weighing in
at more than 8t, the stainless steel
rotors needed a special machine tool
capable of handling diameters of up
to 850mm with a length of up to
4.5m.

The greatest challenge involved
achieving the requisite precision of
movement given the enormity of the
masses to be moved and the cutting
forces involved requiring maximum
stiffness and damping with minimum
weight and friction of all axes.