For some time I have been working on using model trains based on Meccano and the many copies of the system. The obvious choice is 0 gauge as this is the gauge of railway first made by Hornby. Meccano came first and the first Hornby trains used an element of Meccano in their construction. However the connection was never persevered with.
Basically Meccano is too big for 0 gauge. Commercial mass produced trains of the type Hornby made would not have a market so obviously the diret connection was dropped.
In a book on the history of Hornby there is a drawing originated by Hornby in the 1920 of an electric locomotive bodyto be used with Meccano that never went any further. One or two people have made the model and basically it is way out of scale for 0 gauge.
So what gauge would work with Meccano. Well the holes are 1/2" apart and a scale of 1/2" = 1' is 1/24.
Gauge 3 has track 2.5"/63mm between the rails so this seemed one place to start.
I had built a chassis based on a Meccano idea and tried it on 0 gauge, but it did not really work so I converted it to gauge 3. I also added a latching relay so that the chassis would reverse at each end of a straight run without human intervention.
It worked. Gauge 3 is a good gauge for Meccano, and auto reversing with a latching relay worked. So here is a film of it in action (in my rather untidy garage):