Harrison Alpha 1760XS

The Harrison Alpha 1760XS is the largest 2-axis Alpha, and the only one with a 230 mm (9.1 in) spindle bore on offer. Swing over the bed is listed as 760 / 800 mm (29.9 / 31.5 in), and the bed comes in six lengths up to 6,000 mm (236.2 in) between centres. It is still a CNC/manual combination lathe, with handwheel operation available on a machine of this scale.

Three spindle configurations appear in the table. Bores are 104 / 155 / 230 mm (4.1 / 6.1 / 9.1 in), noses are D1-11 camlock / A2-11 / A2-15, and speed ranges are 26 - 2,000 / 10 - 1,400 / 4 - 600 rpm. The 230 mm option is the big-bore, slow-speed choice. Colchester ties two other rows to it by name: swing in the gap becomes 1,050 mm (41.3 in) and swing over the cross slide 605 mm (23.8 in) with that bore, against 1,040 mm (40.9 in) and 560 mm (22.0 in) otherwise.

A bore of that size lets pipe with couplings and large hollow work pass through the headstock. At 4 - 600 rpm the big-bore spindle is slow, as it has to be with heavy, long stock, and threading on large diameters is the kind of job it suits. Chuck sizes run 16 / 20 / 24 / 28 in (406 / 508 / 610 / 711 mm).

Spindle power is 18.5 kW (24.8 hp), the same as the smaller Harrison Alpha 1660XS, so the gain here is capacity and not cutting power. Buyers who need more power and milling at this swing should look at the XC version. Steady rests, hydraulic chucking and a swarf conveyor are optional.