Mazak QT-Ez 12

The Mazak QT-Ez 12 is the 12 in chuck, two-axis member of the QT-Ez turning centers, with a spindle motor listed at 22 kW (30 HP) (30 min. rating) and a top speed of 4,000 rpm. It turns Ø16 in (406 mm) by 21 in (533 mm), passes Ø3 in (76 mm) bar and holds 12 tools.

It helps to be clear about what the larger chuck does and does not buy. Maximum turning diameter is the same Ø16 in (406 mm) the QT-Ez 10 offers, and bar capacity is the same Ø3 in (76 mm). Turning length is shorter, 21 in (533 mm) against 23 in (584 mm) on the QT-Ez 10, and top speed is lower, 4,000 rpm against 4,500 rpm on the QT-Ez 10. So the QT-Ez 12 does not turn bigger parts than its smaller sibling. It is the choice for gripping larger blanks securely and for taking heavier cuts on them.

That is where the motor comes in. The QT-Ez 10 lists 15 kW (20 HP) (30 min. rating); this machine lists 22 kW (30 HP) on the same 30 min. basis. On large-diameter steel or cast parts, where depth of cut is usually limited by power, the difference shows directly in roughing time. Mazak's table gives neither a continuous rating nor a torque figure, and low-speed torque is what a 12 in chuck machine lives on, so request the torque curve before quoting heavy work.

Travels are 9 in (229 mm) in X and 25 in (635 mm) in Z under a Ø27 in (686 mm) swing. Only those two axes appear in the table. The QT-Ez 12M lists a 3,300 rpm spindle and a Ø14 in (356 mm) by 19 in (483 mm) envelope, so the plain model has the higher speed and the larger envelope of the two.

Chip handling deserves attention at this power level. Mazak's series page lists a chip conveyor, a coolant system and a mist collector among the QT-Ez equipment without saying which are standard.