An application engineer at INDEX answers questions about how the company completely redesigned its TNL12 sliding headstock lathe to increase the machine’s performance.

1. What drove the decision to make the new TNL12 convertible between sliding and fixed headstock operation?

Our larger sliding headstock lathes have been convertible for some years now, and it’s become a distinct and popular feature, so we incorporated it into our smallest machine of this class.

When you’re running parts on a Swiss-type machine, you’re always going to end up with a void between the guide bush and main spindle and the collet of your bar loader. That translates into losing 8" to 12" of every bar of material. Consequently, a lot of shops end up buying separate sliding headstock and fixed headstock machines, so they can avoid waste. The redesigned TNL12 can operate in either configuration, requiring just five minutes to changeover the machine.

2. How does incorporation of integrated motor spindles impact the machine’s performance?

Most Swiss-type machines, including the previous version of the TNL12, use belt-driven systems, introducing limitations. More mechanical parts result in more heat, vibration, and wear to the machine and cutting tool.

Switching to integrated spindle motors eliminates many issues. You can put a 0.015" end mill on the TNL12 and cut with it all day with exceptional accuracy. You’re not going to get that tool life and performance with a belt-driven system. There’s less heat generation, so processes are more stable. You’re also able to accelerate and decelerate noticeably faster when you remove the mechanical transmission of power.

3. Which applications will see the most benefit from the new workpiece removal unit?

The traditional approach with Swiss-type machines is to flush parts out with coolant. That’s usually acceptable if you’re working with small parts, but when producing longer, heavier ones or parts with diameters close to a machine’s maximum diameter, parts can get hung up during evacuation. With the TNL12, there’s now an option for a mechanical gripper to move finished parts to a conveyor that takes them out of the work area. This greatly increases process security and predictability for manufacturers producing parts at the upper size limits of the machine.

4. What other aspects of the machine increase its overall flexibility?

The use of turrets allows more freedom of movement compared to gang-style tooling traditionally used for Swiss-type machining. There’s less potential for interference and more freedom in your programming.

Also, the TNL12 offers a tremendous number of programmable axes. An operator can use the turret’s vector axis as a Z-axis, eliminating the requirement that tools be at zero. The turret also offers a rotational H-axis, allowing the machine to host two or three static tools on a turret station with no reduction to Y-axis travel.

Lastly, the machine’s redesigned back-working attachment provides full 3-axis machining on the counter spindle, allowing efficient machining of more complex parts.

FOR MORE INFO: https://us.index-traub.com