I am sure this has been suggested before, but when I saw a mention on the 16mm scale forum,of using 24mm gauge to represent 18in gauge in 16mm/ft scale, I got thinking.
Could I produce track 3D printed inset track(possible mixed gauge), and yes I can. I stalled as I was looking for a supply of 24mm gauge wheels. Then tonight I remembered to check a cheap plastic trainset I had got a couple(+) years ago, and the gauge is 24mm. Some bogies from the wagons, and I should be able to do something. The loco in the set is battery operated so not sure about that, but battery is better than nothing. Thats something else on my list to do.
Narrow gauge Francophile interested in 1m, 60cm,50cm , 40cm and smaller gauges . Build in scales from 1/6th to 1/24th. Also 1/32nd and 1/35th using 16.5mm track to represent 50cm and 60cm gauges. http://www.rue-d-etropal.com