| Static deflections can lead to geometrical inaccuracies in the components being ground and can also limit the production rate in the grinding process. This project studies the static deflections in surface grinding using the Brown & Sharpe 824 Micromaster and Blohm Planomat 408 grinding machines in the Grinding Lab at Dalhousie University.;An experimental procedure was developed to indirectly measure the static deflections by comparing the actual mass removed during a grinding pass to the mass that would have been removed if there were no deflections. A rectangular 1020 low carbon steel workpiece was used in these experiments. This measurement technique has shown to be an effective method to calculate the actual depth of cut for the typical 5 mum to 30 mum cuts used in surface grinding. The relationship between the spindle power and the static deflections was investigated for the Brown & Sharpe surface grinder. The Blohm Planomat grinding machine, being equipped with both a spindle power sensor, and a force dynamometer, enabled the relationships between the spindle power, the normal force and the static deflections to be investigated. For the Brown & Sharpe surface grinder, the experimental results show a linear relationship between the spindle power and the static deflections, which agree with the literature. For the Blohm Planomat grinding machine, however, the relationship between the spindle power and the static deflections contains an unexpected offset. This offset is likely due, in part, to backlash in the spindle lead screw. A further investigation of the relationship between the total static deflection and the individual deflections of wheel-workpiece-machine system was also conducted using the force data measured in the experiments on the Blohm Planomat 408 grinding machine. |
