Liebherr LC 180

The Liebherr LC 180 is a gear hobbing machine for workpieces up to 180 mm in diameter with 400 mm of axial travel. Liebherr lists it with two hob heads, and the choice between them sets the module, the hob size and the spindle speed all at once, so it is the first thing to settle.

The standard hob head has 13 kW of drive power and a cutter spindle speed of 2,250 rpm. It cuts up to module 6 mm, carries hobs up to 150 mm in diameter and has a shift distance of 200 mm. The direct-drive head is an option with 23 kW and 6,000 rpm. That is about 77% more drive power and well over twice the spindle speed, but the limits tighten: module 4 mm, a 90 mm hob and 180 mm of shift.

Read together, those rows describe two different setups on one base. The direct-drive head is for small hobs turning fast on fine-pitch teeth, where a 90 mm hob needs the rpm to reach a useful cutting speed. The standard head gives up speed for a larger hob and two more millimetres of module. A shop whose parts straddle module 4 mm should work out which side most of the work falls on, because the table offers no head that combines the 6 mm module with the 6,000 rpm speed.

The workpiece table is listed at 800 / 250 rpm, and the row does not say which figure belongs to which configuration, so ask for the table speed in writing along with the head. Shank-type cutters can be clamped up to 360 mm long, and the machine runs Liebherr's LHGearTec software. For larger gears on the same heads, the LC 280 takes workpieces up to 280 mm; the LC 300 moves to a 27 kW head and 700 mm of axial travel.