It is critical that the magnetic poles on each unit are properly aligned, but how much deviation would be acceptable? The units have worked fine even with 2-3 degree misalignment, but this misalignment will end up affecti ng the transfer torque.
It is not visible to the eye, but the actual magnetization lines are set at 45 deg. to the axis for the perpendicular configuration and in line with the axis for parallel configuration units. (See photos below)
Parallel Configuration ↓
Perpendicular Configuration ↓