[OXO cube]

think i have got it 
please correct me if i am wrong guys 

inline :-
all pinions standard 5.5mm
crown gears increase in diameter with tooth number 

side winder :-
6.5 or 6.75 pinions 
spur gear diameter 18 or19 mm (tooth depending)

angle winder :-
same pinions typically as side winder 
spur gear diameter 16.8 or 18 mm (tooth depending)
16.8 , fixing hub is towards the chassis and lower tooth gears
18 , fixing hub is towards the wheel and higher tooth gears

i think 

comments please