Another photo from the Hornby Magazine Facebook feed. This time showing the new bridge and factory ends I've built fro Twelve Trees Junction.
The bridge is a 3mm thick plywood deck with plasticard sides. While fiddly and time-consuming to make, the worst part of these was marking them out. My best guess was that the radius of the top curve should be 24 inches.
Finding something to draw around proved impossible. Using a length of string and pencil as a compass might work, but I tend to find the string stretches slightly as you draw the curve which would look odd.
The solution was to mount a couple of 24 inch SMP point plans on a bit of cardboard and cut around the inner curve. This was them used as a template to draw the line. The job took no time to do but a heck of a long while to think about!