Makino a91nx

The Makino a91nx is a four-axis horizontal machining center built on an 800 x 800 mm (31.5 in x 31.5 in) pallet, with 1,400 mm (55.1 in) of X, 1,200 mm (47.2 in) of Y and 1,350 mm (53.1 in) of Z travel. Makino describes it as the newest member of its nx series, aimed at the market for oversized components. The spindle is CAT50, with HSK-A100 listed as the alternative shank.

What sets the size of a job here is the swing rather than the pallet. The workpiece envelope is Ø 1,450 x 1,450 mm (Ø 57.1 in x 57.1 in), so a casting can hang well past the square pallet as long as it clears that cylinder when the table turns. Pallet load is 2,000 kg (4,400 lb.), and Makino lists 3,000 kg (6,600 lb.) as the higher rating for heavier parts and fixtures.

Three spindles appear in the table: 10,000 rpm as standard, with 8,000 rpm and 15,000 rpm versions as the alternatives. Makino's specification block gives no power or torque for any of them, so the choice between the slow and the fast spindle should be made from Makino's curves for the actual cuts, not from the speed alone. Axis motion is quick for a machine of this size, at 60,000 mm/min (2,362 ipm) rapid and 50,000 mm/min (1,968 ipm) cutting feed.

The tool side is built for long, heavy cutters. The standard magazine holds 60 tools, with 185 and 297 tool magazines offered. Tools can be up to 900 mm (35.4 in) long with either a CAT or an HSK shank and up to ∅ 356 mm (Ø 14.0 in) in diameter. Tool weight is 30 kg (66 lb.) with the standard magazine and 35 kg (77 lb.) with the 185 or 297 tool ATC. Tool-to-tool time is listed as 1.8 sec, with 2.2 sec in brackets and no note on which configuration that applies to.

Next to the a92, the a91nx gives up some length for speed. The a92 has an 800 x 1,000 mm (31.5 in x 39.4 in) pallet and 1,520 mm (59.8 in) of X, but rapids at 50,000 mm/min (1,969 ipm) and starts from a 40 tool magazine.