The Jaw coupling arrived. It is beautiful.
I sourced it from an Auto-parts store, Each half can ordered to fit the shaft size one requires.
The rubber insert absorbs misalignment and shock, this can be replaced and bought separately if it wears out.
The whole coupling cost only $79 !.
So I can test the whole assembly…Here is a clip of it rotating.
There is a bit of vibration, Once the prop is in a water tank I will test it at Max RPM and get some data, if it doesn’t fly to pieces.
Max RPM ~2000, will be the true test of the coupling, bearing and shaft. There is a good chance something will break catastrophically… we will see.. today hopefully.