Module construction as per HOTrak
This diagram shows the main components (from bottom to top) frame, support, and foam.

The dimensions:

Foam - 2" thick extruded foam, 22.5"W x 3'10.5"L

Support - 1/4" plywood, 22.5"W x 3'10.5"L
Cut the supports for underneath from the rectangles cut out of the middle of the support layer plywood.

Frame is constructed of 1x4 or 1x5 (nominal) pine. The end plates are the full 24" width, with the sides 3'10.5" (since 1x wood is actually only 3/4" thick).

Glue and screw the wood frame together. Using a large flat surface like a table or floor, turn it so it is "upside down" and fit the foam in to the bottom. This will ensure that the top is flat when you turn it back over.

Fit the support rectangle in against the foam, and glue with something like Gorilla glue that will bond the foam to the wood. Be careful because the Gorilla glue expands as it cures, and can push things out of alignment.

Lastly, add the strips up against the support layer.

There are many ways to wire, connect track, and join the modules together. Some people add alignment pins and so on to ensure they go together precisely every time.


Attached Files Image(s)
Here's a module system developed by Dennis Ivison from Garden Grove CA. It uses 2" Styrofoam only for the modules & PVC pipe for the legs. He built his home layout using these modules for his fictional narrow gauge On30 South Pacific Coast RR. His are all 30" by 72" to hold up a lot of scenery & structures. The foam was glued together using "Liquid Nails for Paneling & Molding Adhesive". But if you chose this system the modules could be whatever size works for you. The modules are very strong but are also very light compared to wood or steel frame & plywood ones.

Andy Jackson
Santa Fe Springs CA
ATSF/LAJ Ry Fan & Modeler

Thanks for adding that. I have a friend who built his home layout in a similar fashion, using just the foam and steel studs.

If your modules are going to be transported to a club or display, the wood frame protects the foam, and the modules are actually boxes together in pairs so the "good sides" face inwards.

To lighten my design further, the 1/4" ply could be replaced with the 1/8" door skin or luan, and it could also be used for the sides. By gluing the foam to the support panel, it becomes incredibly strong.


Forum Jump:

Users browsing this thread: 1 Guest(s)