sheet metal spinning:
The symmetrical parts can be formed over mandrels by using sheet metal spinning process. The rotation of sheet metal with high speed on a spinning lathe. The axis- symmetric components formed by using spinning sheet metal forming as shown in figure.The spinning metal product such as Aircraft engine parts, Jet engine parts, truck wheels and etc.
The basic metal handing tool is called spoon (blunt tool). Require shape of sheet metal to prepare mandrel or former. There mandrel made from hard wood (or) cast or carburizing steel depends on the sheet metal to be spun and number of operation require from same form. The mandrel is mounted on lathe head stock. The lathe is used in this process like as ordinary type. The carriage tool rest is provided to hold the blunt tool. The mandrel speeds depends on the diameter thickness and workability of metal. For heavy sheet metal to require low speed and vice versa.
First, the sheet metal cut with circular shape. Which sheet metal is held against the mandrel and compress by a bad which support by tail stock center of lathe. The sweeping motion obtain in the sheet metal evenly transformed around with the mandrel into require shape.
During the spinning of metal, the lubrication obtain like as been wax, soap and linseed oil are used to reduce the friction at tool and work contacting. which spinning tools can be made parts such as hardened steel with aluminium and solid brass for spinning stainless steels and mild steel. Either both the hand spinning metal or CNC spinning metal the rollers are mounted on end of the tools.
Shear spinning metal forming:
The shear spinning is also called as flow turning, spin forging or power spinning. That provides an axis- symmetric conical shape or curvilinear shape. During the process sheet metal thickness of blank is reduced in forming.The Shear spinning is as shown in above figure.
The maximum diameter of cup at bottom of shape and then thickness of metal is reduced in the side of walls. The tool is required higher force in the spinning of metal. The single roller is used two rollers are preferable. In two rollers the roller are kept in opposite side to each other to attain the force balance. In this method the rocket motor casing and missile nose cone is span.
Tube spinning sheet metal forming:
The tube spinning provide symmetrical products that usually start from preform of cylindrical blank. That tube spinning is carried out both external and internal shape of surface. In this case reduce the wall thickness and done by long tube. That is employed with three rollers for complex design shape. The sheet metal ironed ahead of rollers. That is increase the hardness and tensile strength of sheet metal.
Advantages of spinning metal:
- No material wastage during process
- Tooling and setup cost is less
- Material properties not affected
- Flexibility to adopt any complex design changes
- The unlimited variety of circular shape