Can you explain what the Marklin curved track radii are?
Marklin C-track uses 5 different radii. R-1, R-2, R-3, R-4 and R-5. They are color coded on their boxes. A standard track piece is 30 degrees, and it would take 12 pieces to make a full circle (30 degrees * 12 = 360 degrees).
R-1 is 360mm (approx 14-11/64 inches)
R-2 is 437.5mm (approx 17-7/32 inches)
R-3 is 515mm (approx 20-9/32 inches)
R-4 is 579.3mm (approx 22-13/16 inches)
R-5 is 643.6mm (approx 25-11/32 inches)
