OPTIMAL ANGLE OF ATTACK IN TUBE SPINNING

The angle of attack of the roller used in tube spinning has an essential effect on the build-up and bulge ahead of the roller, the variation of the inner diameter of the spun part, and the forces applied to the roller. Recognizing the importance of determining a proper angle of attack in practice, an analytical method of defining the optimal angle of attack in tube spinning is proposed on the basis of minimizing the resultant spinning force. The optimal angle of attack in forward and backward tube spinning in the form of a transcendental function of the relevant variables such as feed rate, reduction of wall thickness and friction factor, can be solved numerically by the Newton-Raphson method. The optimal angle of attack calculated according to the method proposed is in agreement with the data on desired angle of attack reported in the literature.