In this article we will discuss about:- 1. Meaning of Metal Spinning 2. Advantages of Metal Spinning 3. Metal Spinning Speeds 4. Types 5. Design Considerations.
Meaning of Metal Spinning:
Metal spinning is the operation of shaping thin sheets by pressing them against a form. The sheet is rotated at a very fast speed and blunt tool is used to force the metal flow in the desired form. Spinning is carried out on an ordinary lathe. The lathe is just like an ordinary wood working lathe with the only difference that in place of the usual carriage a tool rest is provided to hold the blunt tool.
The drive is obtained by pulleys and belts. First a form or pattern of the desired shape is prepared. The form might be made either from hard wood or cast or carburising steel depending upon the sheet material to be spinned and number of operations required from the same form.
When spinning of large diameter are to be produced and the working is performed on the outside periphery, then it is uneconomical to make forms entirely of steel. In such cases wooden centre body fitted with machined steel inserts at the outside edge, where spinning will take place, is used.
The form is provided with a necessary mandrel which is fixed in the headstock of lathe. The cast iron form should be given very good surface finish in order to avoid the interior imperfections and have better finish on the spinned product.
The steel sheet is cut in a circular shape whose diameter is calculated on the basis of the shape of the desired product. The sheet is held against a compression pad which is supported by tailstock centre. If the shape is too complicated and where deep drawing is required the sheet may have to be first given simple form by press operation.
The forming of the sheet to the desired shape is achieved with the aid of blunt hand tool which presses the metal against the form. The blunt tool is supported on a compound tool rest and pivoted about a pin fixed on the tool rest. Some means are also provided for supporting a trimming cutter or forming roll in the rear of lathe.
Read more: Metal Spinning: Meaning and Advantages
