Shay Larger Scale section very misleading

[DavidT]

If a wheel is 52mm dia in 3/4" scale it will be 104mm in dia in 1 1/2" scale. Not 2.14 times, of what is was in the smaller scale. The example given is incorrect! Axles and bolsters will be 2.14 times what they are in 3 1/2" gauge for 7 1/2" gauge. So the frame spacing shown the the Larger Scales section are 2.14 times the 3/4" scale dimension, which is wrong. The spacing should only be doubled. No wonder Ironman is confused. The boiler shown will fit for 7 1/2' gauge but not 7 1/4" gauge without spacing out the frame

[Bill Holland]

Just make a ratio based on the wheel standards, and answer you get from the ratio is what you multiply all the parts by to make them work, atleast to fit on the track. Will need to redesign many things, as some say, you end up with whole new set of drawings.