The main bearing on the timing side has been bored and that happened in no time at all. As per the YouTube videos, using the CNC control to start/stop the motor and feed the cut makes these bores quick to do. Even Bob was able to drive the machine and complete the operation.

All of the bores on the timing side are done now, so the next job is to fit the drive side without removing the timing side from the mill. The dowels will ensure that the cases go back together in the same place, so that the two main bores for the crankshaft to run in are completely concentric. (In theory anyway!).