Because I want these to fit next to each other they all need to be uniform. To do that I enlisted the help of my lovely wife, Amy, and we went to work.
To start with I measured out 2 foot sections down the length of each sheet. I marked the foam on each side so I could get a nice straight line to cut.
Next, I clamped a straight edge to the foam on each side lined up with the 2' marks. I got out my trusty Hot Knife and started to cut. To cut these large pieces, it took some team work. I don't know if you could do this by yourself, but I know it was easier with help.
I let the Hot Knife warm up and then I lined it up with the two straight edges. Using a piece of wood on the side with no handle we pushed the hot knife through the foam along the lines. I all honesty, this was kind of a pain in the @$$, but the results are much nicer than I could have accomplished free hand. If you know another way to do this, I'm open to suggestions.
After cutting several boards I'm thinking that I'm going to make a slight change to the plan. I'm leaning toward 2 sections that are 2' x 4' and 2 sections that are 2' x 2'. This will still give me lots of layout options, but would reduce the number of cuts and joints on the table.
Here are a few of the boards cut and lined up so you can get an idea for how these will be laid out.
I took my hot knife to the four boards that will make the first 2' x 2' section and here are the results. I used my sketch as the guide and cut out the top layer. I used that as the template to sketch out where I would be cutting into the next level and then used that as the guide for the 3rd sublevel. I left the bottom sheet intact.
I'm thinking about whether or not I could make these double sided. Maybe have the bottom as just a mostly flat field with a few sub-levels cut in. I could use them as the base for a different field and use scatter terrain to build up when I use that side. I'm not sure how well the surface texture (flock) would hold up, but it might be worth testing it out.
More to follow soon.