Midwest Manufacturing News • July 2016 • 11-Axis Automatic Lathe

The TRAUB TNL32-11 sliding/ fixed headstock automatic lathe has a headstock moving in the Z-axis, an upper and identical lower turret with X, Y, and Z axes, and a counter spindle movable in the X and Z directions. It offers a front working attachment that sits on an additional cross-slide moving in the X- and Z-axes, providing the user with freely positionable tools and enables the use of up to three tools, simultaneously and independently of each other. “The 11-axis machine can save machining time—especially for components with a high proportion of drilling,” said a company spokesperson.

In addition to the two linear X and Z axes, the front working attachment features a CNC circular axis. By the interpolation of the rotary axis with the X-axis and the C-axis of the main spindle, the front working attachment can also be used in the Y direction using an interpolated Y-axis. “The benefit: when a drilling tool needs to be corrected to exact center, the necessary corrections can be performed via the CNC controller. That can help with small parts that react with great sensitivity to even minimal offset errors,” said the spokesperson.

The front working attachment makes eight additional tool stations available. Four of them are used to mount fixed tools, the other four are for live tools.

There is also a station for a workpiece gripper, which can unload a machined workpiece from the counter spindle. While the finished workpiece is discharged from the counter spindle, the next part can be machined with two tools at the main spindle.

With an output of up to 3.4 kW and a maximum speed of 12,000 RPM, the tool drive in the front working attachment is designed for high power. The tool holders are stiff with a mounting shank diameter of 36 mm. Individually controllable coolant pressure of up to 80 bar is available at every station. One live station can be used as a deep-hole drilling station with a coolant supply up to 120 bar. The front working attachment can also be used as a tailstock when producing long components.

In addition to the advantages of the front working attachment, the TRAUB TNL32-11 offers the many other benefits of the entire TNL series. The work area is accessible to the operator due to its high and wide sliding door, helping to simplify set-up and changeovers. A large inspection window allows the operator to keep a close eye on the machining process. “The long Z travel of the headstock means the machine can easily be used for sliding or fixed headstock turning without compromises in less than 15 minutes,” said the spokesperson.

Tool turret indexing is performed using an NC rotary axis that controls movement via an internally meshing planetary gear. This allows the turret to be indexed to any position without requiring a mechanical locking mechanism. The free positioning of the turret makes multiple-tool assignment possible on each station.

Another highlight is the “Dual Drive,” consisting of two drive trains integrated within one turret. This patented drive solution helps reduce non-machining time and also machining times per piece. While one tool is in use, the tool intended for the next work step can be accelerated up to the desired speed during main time and is immediately available at full speed after the turret indexing operation.

“Jerky accelerations and delays that were previously unavoidable when reducing auxiliary processing times are now prevented. In addition, toolholder wear is reduced due to the lower acceleration values. Even with live tools, chip-to-chip times are around just 0.3 seconds,” said the spokesperson.