Hand spinning on these types of wheels, both hands are free (since the wheel is turned with a treadle, rather than by hand), so the spinner can use one hand to draft the fibres and the other to wet them. Modern powered spinning, originally done by water or steam power but now done by electricity, is vastly faster than hand-spinning. The spinning jenny, a multi-spool spinning wheel invented c. 1764 by James Hargreaves, dramatically reduced the amount of work needed to produce yarn of high consistency, with a single worker able to work eight or more spools at once. At roughly the
Rule based DFM analysis for metal spinning Rule based DFM analysis for metal spinning Rule based DFM analysis for metal spinning. Metal spinning is a lesser known metal forming and fabricating manufacturing process. It is more conventionally used for the manufacturing of axis-symmetric parts. Its ability to create parts that require high tolerance and high strength makes it an outstanding process to manufacture a wide range of parts for automobile, aerospace, defence and medical industries. Typical components produced by metal spinning are lamp bases, reflectors, hollowware (pitchers, tankards, vases, candlesticks, etc.), pots, bans bowls and components for electrical equipment. Design for manufacturability (also sometimes known as design