You might also want to consider Woodland Scenics foam risers. They are built to be curved.
Ed.
in article i%8Sb.34928$P% snipped-for-privacy@newssvr28.news.prodigy.com, Frank A. Rosenbaum at snipped-for-privacy@sbcglobal.net wrote on 1/29/04 6:44 AM:
If you are going to cut the foam, you might as well cut the curve right into
> it. Look up or find a benchwork book about 'cookie cutter' table tops. This
> would be much easier than trying to notch the foam.
>
> You might also layout the curve sections on one piece of foam and cut the
> parts out like many people do with plywood to make the curves of a constant
> radius, then splice the parts together to make the full curve.
>
>
> D&Hfan wrote:
>> I've been thinking about how to make a curved track incline (grade)
>> out of foam board for an N-scale layout. I saw a product at the LHS
>> that uses thin molded plastic (styrene) for this purpose. It's a ramp
>> that looks like a series of interconnected hollow abutments which
>> increase in height along it's length. This design makes it flexible
>> enough to bend into a curve. It gave me the idea of how to do it with
>> foam board. I would start by cutting the length of the grade out of a
>> 2-inch thick piece of foam. This would make a long straight ramp.
>> Then I would cut this ramp into small sections about 1-inch thick
>> which could be glued upright to the foam base of the layout along the
>> center line of the curve.
>> I have a few questions about this idea. First, should I fill in the
>> wedge shaped spaces on the outside of the curve? If so, could I use
>> some kind of insulation foam which comes in a spray can? Also, should
>> I cover this foam ramp with something more rigid before installing
>> the cork roadbed? Thanks for your suggestions.
>>
>>
>>