Originally Posted by Dave Allen:
The correct expression for true O scale ratios is 7mm to 1 foot.
No, 7mm/1 ft = 43.5. It is not an accurate measurement, but simply 2 x 3.5 mm/ft [ = HO ], or, in French logic [ actually, French illogic is more correct ] , " If HO is 1/87, then 0 is 2/87 ".
If 7mm were correct, there would be no need for "Scaleseven" in Britain, which runs 43.5 scale equipment on 33 mm [ not 32 mm ] gauge track.
Given a 32 mm track gauge, 1/45 is the "correct " scale.
Best, SZ
