Press fit might be a bit tricky for a beginner to get firm. Keyways too are tricky. Consider Loctite with a pin for peace of mind. Loctite can be used with as good a fit as you can manage easily (for alignment) but does not need to be so precise as a press fit, and does not actually need a gap (and hence slop) as mentioned in some of the older instructions. You can put in a tiny anular groove a thou or so deep if it helps to have a sort of reservoir for the loctite so you feel there is some there. If you screw up the quartering it can be got apart with heat.