How metal spinning works
Date: Jul,29 2019 View:
How metal spinning works?
Metal spinning originated as a handcraft technique with origins, according to some, dating back to 10th-century China. Nowadays it is a powerful and advanced manufacturing process carried out by CNC machines.
Metal spinning produces axisymmetric workpieces starting from a blank. This blank is commonly a flat disk sheet and occasionally a deep-drawn or machined preform.
The blank is clamped against a rotating mandrel using a tailstock system, and the mandrel is shaped with the profile of the inner final workpiece.
Once the blank is clamped and rotated, forming slides drive a rotating tool called a roller against the blank. With consecutive movements called strokes or passes, the roller pushes the blank against the mandrel .
After several backward and forward forming passes, starting next to the mandrel surface to the edge of the disk blank, the material progressively forms closer to the mandrel until the final shape is obtained. A final pass leaves a good finish quality and forms the material tightly to the mandrel to satisfy dimensional and tolerance requirements.
Another common iteration, shear forming, finishes a part in just one pass, with the roller pressing against the metal in a unique fashion. In multipass metal spinning, the unformed flange section of the disk bends forward and backward during the process, depending on the type and direction of the spinning passes. In shear forming, the roller keeps that spinning flange perfectly vertical during the process.
Besides multipass spinning and shear forming is another, less common metal spinning iteration called necking-in or reducing—sometimes referred to as “spinning on air.” As the name implies, it usually requires no mandrel for internal support. It is commonly used for shapes such as gas bottles, which are necked-in out of a tube.
