Knowing some of the OP's design ideas, there is an option not really made that he might have used. Me too.
It likely wont take the hobby by storm. But how many with 0-27 loops wish there was a smaller turn just for trolleys, critters, etc..
I think I was told 0-15" was runnable but ????
Hi Everyone!
I would like to see at least an O24 (measured to outside of the tie) 3 rail tinplate sectional track. Most O27 stuff will handle the O24 curve. It is the knuckle coupler (truck mounted, ridged) that is the limiting factor. I have done O24 in flexible GarGraves and re-bent O27 to O24. Works fine with a lot of stuff.
Take care, Joe.