When figuring out how to properly machine these cases for repeatability, keep in mind that there are three main factors we have to contend with:
1. We need to preserve the fidelity of the feature in question. This means that if we are making a threaded hole, for example, that the dimensions of the hole, the thread pitch, and the location of the hole on the casting have to be perfect. Obviously.
2. We need to preserve the repeatability of this feature by accurately programming it into the machining model so it can be duplicated over and over again.
3. We need to accommodate the limitations of the machine. We are dealing here with an extremely high end 5 Axis mill, but it has dimensional limitations that have to be observed and accommodated.
These three items are what take so much time, and this process would be very different if we were using another machine, and would be different even if another type of 5 axis would be used. So we are tailoring the machine model to the machine we have.