Convert a Train Table to a Construction Zone Table

My little guy likes trucks more than trains, so I thought I'd convert his old train table to something more construction oriented ...

Step 1: The Old Train Table

We had this really cool train table ... which he still uses, but he really like trucks.

I realized that the train surface pops out quite easily and has a nice frame for adding other things.

So I made a new wooden surface and painted it with acrylic paint to look like dirt and stone.

Step 2: Make the Styrofoam Hot-Wire Cutter ...

I made a styrofoam hotwire cutter from some aluminum frame and nichrome wire. A little bit of wood works as an isolator. And my battery charger was perfect for a DC source. Cheaper than buying a train transformer.

Edit: Some more notes on this ...

I picked up the nichrome wire from my local hobby shop for about $.65 per yard. The hardest part is keeping the tension on the frame since the wire stretches quite a bit when hot. You don't want it too hot where the styrofoam smokes. On the 12v setting, it drew about 1.5 amps with 1.5' of wire. Slightly higher current with a shorter length. There are other hot wire cutter instructables on this site which provide more detail on this step. If I was to go with an even shorter length of wire I'd drop down to 6 volts.

In retrospect, I should have made this frame like an X with a bungee on the bottom to keep the wire tight. But it was a hack for a quick one-off. Perhaps version 2 will be more versatile?

Step 3: Start Carving Your Hillside ...

I roughed out some Styrofoam insulation I had in the basement and used the hotwire cutter to carve it. Then we put a base coat of black on it. Erica was a great helper. With the base-coat, it looks like something out of Star Wars. Then some more paint layers for stone and dirt ... I really suck at this part.