Both turrets are NC controlled, without a mechanical lock, allowing them to be positioned at any angle through 360 degrees. So multiple toolholders can be used, allowing up to 54 cutters in the working area. All stations can carry either a static turning tool or a live cutter.
Designated TNL18-7B, the lathe can operate with or without a guide bush. Long parts require true sliding-head operation with the bar gripped by a collet and fed by up to 205 mm through the guide bush, which supports the bar close to the cutting tools.
Yet in just 15 minutes, the machine can be changed over to produce short parts in fixed-head mode, with the bar clamped by a collet in the spindle and moved 80 mm into and out of the cutting zone using the Z-axis motion of the headstock travelling at up to 40 m/min. Eliminating the guide bush avoids the need to use expensive ground stock. The process is also ideal for applications where a guide bush is impracticable, such as when producing plastic workpieces and those machined from profiled stock.
The 8-station turret with new B-axis is mounted above the spindle centreline, below which is a 7-station turret which moves in three orthogonal axes. Turret rotation is faster than that of an indexed turret, matching the linear speed of a gang tool post. Chip-to-chip time is under 0.3 second for adjacent turret stations, maintaining the same low levels of non-cutting time for which sliding-headstock lathes are renowned.
The 3-axis counter spindle is mounted on the same compound slide as the lower turret and swivels independently around the same axis as the turret to offer a parted-off component to seven rear endworking tools, three of which are live, for completion of operations on the reverse.
While work is in progress on the back of a component, front-end turning and prismatic machining with one or two tools can be carried out simultaneously in the main spindle, allowing up to three tools to be in cut simultaneously.
A small footprint, good visibility, convenient access to the working area and ease of maintenance are further benefits of the TNL18-7B. Control is by Traub's own Mitsubishi-based CNC system, TX8i-p, with a 10.4-inch LCD display and integral keyboard.