The influence of band saw strain force on idling power

Strain force is a very important parameter of the general efficiency of the band saw. In order to point out the importance of strain force the paper presents research results of its influence on the machine's idling power. As independent variables two parameters have been chosen: strainforce and cutting speed. References mention a wide range (from 30 to 120 MPa) of optimum strain force values. The choice of the optimum strain force value will thus provide for the higher efficiency of the band saw. For the purpose of the research described in this paper, strain force was measured by an approximative method of measurement. The band saw blade was loaded by a horizontal force of a controlled value. At the same time the lateral inclination of the band saw blade was measured as well. The power of the machine's own resistances was measured at various strain forces. At each level of the strain force cutting speed has been varied by changing the rotation frequency of the electromotor. The change was performed with a frequency transformer. Measurement results are analysed and graphically represented. The influence of electromotor rotation frequency on the machine's idling power is linear and expected, but fhe influence of strain force cannot be called linear, which is an unexpected result.