the fourth principle for deciding on the parting line is to assure plastic part accuracy, for example, when we want to make a plastic gear in an injection mold, it’s diameters d and D must be concentric, if they are accomplished separately with fixed and the half, it is hard to assure the concentricity while closing the mold, if both the diameters d and D are on the moving half, easily satisfy the concentricity requirement.
your blogs about parting line are very useful for me