Selecting a turret or gang tooling for a CNC lathe

Deciding whether to use a turret or gang tooling is one of many topics that seems to engender religious fervor from one side to the other. Let’s start by providing a brief overview of each approach and then dive into the details.

Pure gang tooling is the simplest option for a CNC lathe. The tools sit in a row on the lathe’s cross-slide. To change a tool, an end user takes the following steps:

• Pulls the current tool from the workpiece with a Z-axis motion.
• Slides in the X-axis until the new tool is in position.
• Moves along the Z-axis to start cutting.

A tool turret is more complex than simple gang tooling. A turret holds a group of tools and rotates to bring a new cutting tool into position. Changing tools involves:

• Pulling the current tool back, typically with a Z-axis or combined X- and Z-axis motion.
• Rotating the turret until the correct tool is in position.
• Bringing the tool forward to begin cutting, again with a Z or XZ motion.

Lathe turrets are like the rotary toolchangers familiar to users of CNC milling machines.

Which one is better?

Here’s the top-level conclusion:

Choosing between gang tooling and a turret on a CNC lathe should be based on the kinds of parts being machined: