Skip to main content

Easy.  

 

1) Determine the largest circle diameter that will fit within the walls of your train room.

 

2) Subtract about 12" for overhang clearance to the walls.

 

3) Divide this dimension by 2.  That answers the question "Which radius for big boy is best?".

 

4) Need to know what this is in O3R vernacular?  Take the dimension in inches from #2, above, and stick an "O" in front of it.

 

Well.....you asked.  Just MHO, of course.

 

KD

I ran my Clinchfield Challenger on 0156 at our Mountain Cottage layout but it is now torn down and the 4-6-6-4 sits on the shelf with its big N&W brethern. For a Challenger going clockwise on 072 the right front running board corner is out 2-1/8" from center rail and the right rear cab roof corner is the same dimension. On the inner side of the 072 curve, at mid-engine the overhang is 1-1/8" from center rail. [072 radi measured to center rail]

The Challenger's pilot is as ugly as homemade soap extended on 072 but the maximum overhang reach is up higher.

 

Today on a small layout[9x16] with 084/096 and 072/084 curve arcs on a dual mainline, I tend to favor a max size of Mikados, Pacifics and an occasional 4-8-2 Mountain type. Consolidations and Ten Wheelers look even better. But that is just for my eye.

Last edited by Dewey Trogdon
Originally Posted by RickM46:

I have the VL Big Boy and am running it on its min of O72 small living room layout - yep a lot of overhang; I think another thread indicated that you need at least 5in from the center rail to the wall.  Anyway, in my final layout, I will use at least an O84 or as large as I can get to make taking the curves as smooth as possible. 

I have used Scarm to do my layout and I think I can go to O84 and O96 for my layout with the VL BB residing on O96.

Add Reply

Post
×
×
×
×
Link copied to your clipboard.
×
×