I want to build a layout using 1 1/2 - 2 inch sheets of extruded insulation board over an open framework, then roadbed, then track. Can I still use under table switch machines?
Thats a good question…I too built a layout using 2 inch foam boards…there was an artilce awhile back from a guy that used pc bread boards for mounting the tortise motors…but I don`t remember the month or year of the issue.
A tip on wiring track…I used a 9/32" brass tube that has one end filed inside to a sharp edge…I use this to make a hole in the foam and stick a plastic drinking straw thru it …makes things alot easier to run wires.
The Atlas ones only have a 1-inch high throwbar, so they won’t work.
Peco switch machines attach to Peco turnouts, and depend on the Peco spring to keep the rails in place after they throw. They require cutting a hole below the track for the whole thing to fit into. This is actually easier with foam than anything else, particularly if you also use foam roadbed.
I don’t have an Tortoise or Tortoise-clone machines, so I’ll let someone else handle those.
tortise switch machine will work as long as you replace the original wire with a longer and stiffer wire. they are easy to install but will take some time getting everything lined up correctly.
another option is to use the switch master and they operate on the same principle. very easy to install and more forgiving on the alignment. they can be used on any thickness of subroad bed. although there are no additional contacts, like the tortise, they can be added with another kit. http://www.builders-in-scale.com/bis/sm-home.html
you didn’t mention if you were going to have any wood under the 2" foam. with either of the above techniques, a small square piece of wood can be glued to the bottom of the foam for a stronger set-up.