Production Type Thread Milling Machines

Production Type Thread Milling Machines

Production Type Thread Milling Machines - In the production type machine, the conventional lead screw is replaced by an accurate master screw that rotates with the spindle, and a stationary segment. Each lead or pitch requires a separate screw and segment. The floating work spindle rotates and advances, producing the required helix.

These machines are semiautomatic, the work being plunged into the nontraveling, rotating cutter by a cam. The in feed rate is controlled by change gears. The work rotates 1.10 revolutions, the work backs out of the cut, and the machine stops automatically for unloading and loading.

In this machine, work is held in a collet, chuck, or fixture and multiple thread cutters are used for both internal and external threads. Milling circular grooves, on some models, requires the use of a no lead attachment.

(2) Planetary Thread Milling Machine

This type of machine is especially adapted to threading odd shaped cumbersome parts that are difficult to chuck in a conventional machine. It is not, however, suitable for milling long threaded sections, such as lead screws.

The workpiece, on this machine, does not revolve but is held in a suitable fixture, tied in with the head or to the table, depending on the model, facilitating handling of work in which unbalanced conditions would make the rotating of the workpiece a difficult procedure.All motion is confined to the cutter, which rotates and revolves around the work. Both internal and external threads may be milled independently or simultaneously on the same job.