Peco and Atlas turnout geometry question

[Anonymous]

I have been using 3rdPlanit software to plan my next layout (HO Scale). I have noticed that the large radius code 100 turnout from Peco has a diverging leg at 12 degrees. The No. 6 Atlas CustomLine turnout (also code 100) has a diverging leg at 9.5 degrees. I find this confusing since I always thought the radii and frogs of the two turnouts were about the same. Can anyone explain the difference in the geometry of these two turnouts? I would appreciate it because it would help me make good decisions regarding how to arrange the turnouts in congested areas. Thanks in advance for any help you can provide. - Ed

[AltonFan]

Peco actually doesn't make numbered turnouts; the diverging track is a fixed radius curve rather than a frog angle. Atlas custom line has standard numbered frogs for their turnouts.

You'll have to check Peco's literature to find out what the radius if the diverging track is.

Hope this helps.

[Jetrock]

Those numbers are also in the Walthers catalog if you have one handy. I'm still trying to figure out how to customize turnout geometries--I want to use 3rdPlanIt to do trolley turnouts, which have a 6" radius!

2.5 degrees of difference (between the Atlas #6 and the Peco large-radius) is kind of hard to tell apart merely by eyeballing.

The short-radius Peco turnouts are around 22.5 degrees of curve. Great for moving things sideways if you don't run those big engines...