Baseboard size for N gauge double oval

[Mississippi Bullfrog]

Just starting my planning. My original idea was a 4x2 baseboard for a simple N gauge oval. But I think I’d want a double oval with some sidings in the centre.

I’ve read that ideally you’d want the radius of the curves to be 11” to look right. So that suggests I need to use either 2nd & 3rd radius curves or 3rd & 4th radius. The latter needs a base at least 27” width. In which case I need a slightly larger baseboard than 4x2.

Am I right in thinking the larger radius would work and look better?

[brian1951]

If you can use 3rd or 4th Radius, makes for better running of longer locos or rolling stock.

[Mississippi Bullfrog]

If you can use 3rd or 4th Radius, makes for better running of longer locos or rolling stock.

Thanks. A slightly larger board it is then.

[Mississippi Bullfrog]

Next question....

If I go to a 30"x60" board that ought to be just about big enough to fit a double loop of 3rd & 4th radius. I don't have anywhere I can leave a layout permanently so it needs to be portable. Ply is quite heavy. When I built model aircraft I got into using a lot of foam and was surprised how rigid it can be.

I use celotex insulation panels in my beehives. It is a dense foam, very rigid, comes in various thicknesses, is fire resistant, can be scuplted/shaped/carved/sanded and would weigh far less than a ply board. It is easy to drill the holes for wiring. I would need to glue the track down rather than pin it. It also has good sound deadening properties.

Has anyone tried using it as a baseboard?