Bourn & Koch 400H

The Bourn & Koch 400H is a 7 axis horizontal CNC gear hobber for gears and splined shafts up to 400 mm (15.7 in) in diameter and 6.4 Module. Maximum axial travel is 1,250 mm (49.2 in). It is the one H-Series model listed with seven CNC axes; the 100H below it and the 600H above it are both 6 axis machines.

This is a different class of machine from the next size down, not a stretched version of it. Against the 100H, spindle power goes from 2.5 kW (3.4 hp) to 15 kW (20.1 hp) and maximum hob diameter from 101 mm (4.0 in) to 203 mm (8.0 in). Speeds fall to suit the larger tools: the hob runs at 20-375 rpm and the work spindle at 0-80 rpm. Weight is approximately 16,000 lb (7,258 kg).

The standard build is fuller than on the smaller hobbers. An integral direct-drive work spindle, a CNC operated tail center, a programmable Y-axis, automatic lubrication and speed and feed change in-cut are all on the standard feature list. Hob shift is 200 mm (7.9 in) against a maximum hob length of 215 mm (8.5 in), and the hob swivel is power-programmable over +/- 45 deg.

Control is a Fanuc 0i CNC with the Bourn & Koch HMI. Options to settle early include the chiller for cooling the integral C-axis motor, a quick change hob arbor clamp, an adjustable roller steadyrest for long shafts, an extended bed, a chip conveyor and a mist collector. For shops replacing older mechanical hobbers, Bourn & Koch says the workspindle bolt pattern on the 100H and 400H is designed so that Barber-Colman tooling can be reused.