Each main bearing consists of 2 gunmetal halves which fit into a slot in the base, and a cap which bolts to the base. There are 6 of these.
I machined the gunmetal castings, and made the caps.
Before I finished the machining or drilled the holes for the bolts, my phase changer failed, so I finished the job on my (single phase) drill press. Not ideal but adequate.
The Phase Changer has failed at least once every year since I bought it 5-6 years ago. It is the least reliable machine in my workshop. Repairs to it seem to take at least 3-4 weeks on each occasion, which is frustrating. I will borrow a 3 phase diesel generator to keep the workshop in action while waiting (again) for the repairs.