What is an “inverted spindle” vertical turning center and how is it different from just a vertical turning center? As opposed to a horizontal turning center, the vertical lathe’s spindle line runs perpendicular to the ground. The traditional vertical turning center’s chuck opens upward so that parts are loaded downward onto it. In the case of an inverted spindle vertical lathe, the front side of the chuck points down towards the ground, so that parts are loaded upward into it. Manually loading a traditional vertical lathe is easier for the operator because gravity pulls the part onto the chuck. An operator will become more easily fatigued when loading an inverted spindle lathe because the operator will have to work against gravity by holding the workpiece up against the jaws while actuating the foot pedal to close the chuck jaws on the part.
An advantage of the inverted spindle design is that it is much more easily automated because nothing more than a simple conveyor and a sensor is needed to feed the workpiece into position under the inverted spindle itself, to allow the part to be directly picked up and chucked in the spindle by programming X and Z axis motion. No loading arm, robot, or pick-and-place device is necessary.
Austrian machine tool builder EMCO Maier, whose North American headquarters are in Novi, MI has expanded its lineup of turning machines to include three inverted spindle vertical turning centers, with chucking capacity up to 16”. Check out the VT 160, it’s linked to a cool video of two VT 160’s in action. When searching the Techspex turning center database for new vertical lathes available for sale in the U.S. market with up to 16” chucks, I found 93 vertical turning centers manufactured by 33 builders. Some of these vertical lathes are the traditional spindle-up style, while others are inverted spindles. Click the links to view the vertical spindle lathes offered by these builders; Chevalier, DMG MORI SEIKI, Doosan, Hyundai WIA, Mazak, and Okuma.