My wife gave me a Atlas 3 stall roundhouse for Christmas and I am trying to figure out how to add it to my layout. My biggest problem is laying track to it. I am not using a turntable. The approaching track is a straight piece of C55 flex. This will work fine for the middle stall, but what about the ones on either side? Do I use a #5 or #7 turnout before I get to the roundhouse?
The stalls are at 15deg angles, so you're kindof stuck. 15 degree angle equates to about a #3.7 turnout, so any way you go you're going to have to curve the tracks a bit to get them to line up. #4 = 14deg #5 = 11.3deg #7 = 8.13deg Your best bet would probably be to choose one of the larger # turnouts, and then flex the stub outward a bit to get your 15 degree diverging angle. That way, the turnout acts as an easement, and you don't create an S. DISCLAIMER: I know math, not track. PS: If you feel like finding or building a triple turnout, it might save you a bit of space - at the expense of complication...