Wednesday, January 10, 2018

Modular Cliff Terrain System - Part 1

A couple of years ago, I set out to create a rocky hill and cliff system for my 15mm Soviet-Afghan games.  I cut up a ton of foam, started assembling pieces, and realized that there were still some design kinks to work out.  I then realized that I cut the pieces too narrow to do what I had original intended.  So, about 150 pieces of foam measuring about 6'x12' sat stacked in my garage until this past November, when I finally decided that if I hadn't found a use for them after two years, that they might as well get tossed out.  And they were. 

As I mentioned recently in another post, I need more rocky terrain for use in my 28mm post apocalyptic dessert.  In addition to just rocky terrain pieces, I really need a modular cliff system; I came to real this about four weeks after throwing away all of that foam.

So, I started tinkering around with designs, and came up with a modular cliff system, built around 6"x12" foam modules. Big sigh. Life is just too funny sometimes.

So anyway, here is how I am going about making a modular foam cliff system...

The cliff system will be constructed from 1" expanded polystyrene insulation foam, and will need to mate with my existing modular foam terrain.  After thinking about this for a little while, I decided make two different height cliffs; one set  6" high, and the other set 3".  The two systems will be made, such that they can be used with each other.

The basic system will consist of, more or less, straight cliff sections joined by inside and outside corners.  The straight cliffs will have a 6"x12" footprint, while the corner pieces with have a 6" square footprint.  Additionally, I will need a river/waterfall section, and road sections for each height. 

The river sections will consist of 6'x12' modules, one of each height (3" & 6"), and mate with a 12" square river/water fall base.  The roads will employ a total of five 6"x12" sections.  Three will be use to create the slope that transitions from grade to the 6" rise, meaning that the total footprint for the sloped roadway panels will be 12"x18".  The other two will make the 3" clime in a footprint of 12"x12".

I decided to start out with 8 straight, 4 outside corner, and 2 inside corners for each thickness, as well as the two river/waterfall sections, and 5 total road sections.  This will require about three 4'x8' sheets of 1 inch thick foam.  There will also be a pair of transitions go from the 3" cliff to the 6" cliff.

Originally, I was going to buy a couple of sheets of foam, but after looking around my basement and garage, I realize that I must have ten or more sheets worth of foam setting around in the form of scraps that I have collected over the years.  So, time to clean up a bit.

I cut up about half of the foam that I need, before giving in to our single digit high temperatures (our garage is not heated) a few days ago, and will cut up the rest tomorrow (it is supposed to be in the 50s F.

The project currently looks like this:

In the foreground are the 6" square pieces for the corners, the 12" straight pieces are in two rows to the rear, one each for the 6" and 3" cliffs.  Some of the 6"x12" panels are actually deeper than 6 inches, allowing some modules to be deeper in their centers, creating more irregular shaped cliffs. The big stack to the right are scraps.

You will also note the different colors of foam; pink, blue, and green.  Like I said, I have collected scraps for many years.  Sadly, quality control is not what it used to be.  I noted that the green foam is often under-thickness, sometimes nearly 1/8" under, and the pink is often over, sometimes by more than 1/16".  It matters when you stack six of them together.  I'll fix any height problems during construction.

My next post will address joint profiles for the modules, and basic construction of the corner and straight pieces.  Hopefully, I'll have something to share by the end of the weekend.


  1. I'm looking forward to seeing what you come up with. What do you use for slicing up your foam?

    1. A table saw, and a band saw on the smaller chunks.

  2. Man, you have summed up the trials and tribulations of creating foam terrain: inconsistent thickness is a real bugbear.

    1. The blue Dow Corning foam seems to be the most consistent. Unfortunately, that it the hardest one for me to find around here.

  3. That is why you are not supposed to ever throw things away!