A part we make for a customer required different radiuses with extreme tolerances. The only way to produce this part was to use our surface grinders and a spin fixture. But this was a higher production run that required a lot of time on the surface grinder, and included two complicated maneuvers for the operator to perform.
Always looking for ways to improve our processes, our Tool Room Manager came up with the idea of adding a servo system to attach to the spin fixture. Working with a current employee who is going to school for Automation/Robotics, they came up with a solution: using a Servo and a PLC as the main control components, and attaching it to a mechanical drive.
The Servo driven spin fixture has an accuracy of 25,600 steps per revolution at the spin fixture. That is possible thanks to the 4:1 gear reduction of the mechanical drive assembly. Now we have the ability to adjust the angle of rotation in increments of 0.014°! Using a Servo also allowed us to program torque settings, max allowable rpm’s, and it provides repeatable and precise motion even with a changing load. Using the PLC, the angle of rotation, speed, and dwell times after each move are adjustable.
This system provides accurate and repeatable motion for the spin fixture, and takes stress off the operator by eliminating repetitive motion and fatigue. It’s also extremely adjustable allowing us to possibly use it for other parts in the future.