I attempted to repair my machine but I have found the simplest way was to just start fresh. This machine was state of the art in 1989. 28 years later we have better options.
In 1989 the electronics cabinet and the operator control panel where stuffed full. In 2017 I have ample room to work and allow for airflow.
I am using Delta servos on all 3 axes. The Z-axis includes a brake to hold the head up when not under power or during Estop. The spindle will be driven by a Delta VFD. These will be run via a Mesa 7I93 Ethernet and Mesa 7I77 cards. I also have a Mesa 7I76 (stepper) card that I may use to interface the Spindle VFD and use the extra I/O for the tool changer. All of these will be controlled by LinuxCNC on an industrial panel mount touch screen via ethernet.
Follow me on Instagram for in process updates. I ocasionally post videos to Youtube also.