One of the formats we use to build our modules is Free-mo. As a very general statement, Free-mo specifies how modules mate to each other mechanically and electrically, but does not define the shape or the length of a module. It's goal is to let the modeler build a module that looks 'real'. It can take whatever shape and size needed to create a scene that looks more 'authentic'. While Free-mo standards include provisions for single and double track modules, our builders have built them as single track modules only.

A major aspect of Free-mo is that any Free-mo module will connect and work with any other Free-mo module if the standards are followed. The modelers within the Northwest Trainmasters who build Free-mo modules are able to travel with their modules and build layouts with other Free-mo groups and individuals. They did that in 2007 at the National Model Railroad Association National Convention in Detroit. This was a combined setup of the Sipping & Switching Society of North Carolina with many Free-mo modules from Ohio, Illinois, and Wisconsin. Some great images from that show can be seen in the photo gallery of Mr Trains, a great site maintained by club member Mark Goedert.