The traditional vertical turning lathe design remained unchanged for a century, with the main spindle base and the tool carrier mounted in a two-axis slide unit above the spindle. For large parts, this is still the design of choice. However, like every traditional machine design, improvements have been made, and now small to medium parts can be more efficiently processed.
In the 1990s, the inverted vertical turning center was invented. The design takes the traditional VTL and inverts its main components (tooling and spindle) 180 degrees, which allows use of the main spindle to both load and unload blanks and machine finished parts while letting gravity take care of clearing chips and coolant from the machining area.
With the inverted vertical turning design, the inverted spindle moves in both the X and Z axes. A multiple-part conveyor system outside the machining area delivers discrete blanks or near-net shape parts to a pick-up station, picks up the blank, takes it back to the machining area and presents it to the fixed tool turret for machining. When machining is completed, the spindle returns the finished part to the pick-up station, the conveyor advances to move the next blank to the pick-up station and the cycle repeats.
These machines are suitable for a range of small-, medium- and large-batch automation applications and have multitasking capability. These machines can turn and be configured for other metalworking operations such as drilling, milling, grinding, hobbing, rolling and measurement all within the workzone of the inverted vertical machine. The design keeps the footprint small, and without the need for auxiliary loaders, it keeps the mechanics simpler.
For more information about inverted vertical turning, read “A Bird’s-Eye View of Vertical Turning,” “Vertical Turning Upside Down,” and “A One-Stop Shop."
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