I have built my layout using 2" foam and am now facing how to power remote turnouts. The challenges:
The foam is too thick for normal Tortise (or other) installation
It is hard to attach anything to the foam such as a Tortise
My thoughts so far:
Custom build a brass tube link
I have overcome the issue of solidly attaching Caboose Industries ground throws to the foam by mounting the ground throw on a very thin piece of plywood glued to the foam. This may work on the underside of the layout as well.
But I thought I would put this to the best brains out there.
CI ground throws work well mounted on cork roadbed glued to the foam.
You can get longer and stiffer (or not so stiff) wire for the Tortoise links. That might do it. And like you said mount them on plywood glued to the underside of the layout.
Since you’re already gluing a piece of thin plywood under the foam to mount the machine, why not mortise out a recessed area on the underside of the foam so it’s less than 2" thick where your switch machine needs to be positioned?
Use a small piece of plywood, about 1 1/2" larger all around than the Tortoise. Cut a recess into the foam deep enough for the plywood to sit level to the top of the foam. The plywood should be a snug fit into the recess. Cut a hole all the way through the foam slightly larger than the Tortoise. Mount the Tortoise to the plywood, set the plywood into the recessed area, lay track over the top of the plywood.
I’m in the midst of building a layout with 2" foam now. How to mount the tortoises was a major issue when making the choice.
Fundamentally, there’s no problem using a Tortoise. You just need to get a longer wire than what they provide (and the instructions actually even say this). Generally you’ll want it to be a hair thicker than what comes with them too.
As to mounting them, Don Z and Darrell’s solutions both work. Personally, I laid 1/4" plywood on my benchwork, with the foam over that, specifically so I would have a mountable surface on the underside…
If you’re too late for that, I’d suggest the “glue a piece of 1/4” plywood under the turnout" solution. I’d never thought of mortising the foam out, but it’s a darn good idea. That would avoid the whole “need a longer wire” issue…
The “drop in from the top” solution works, but is far harder to deal with if you ever need to adjust, change, rewire or otherwise mess with your tortoise machine. They’re very reliable, but it’s still a risk. What if you want to access the built in SPDT switch contacts for signaling later on? Now you’re either trying to work up through a little hole in the foam, or you’re pulling up your turnout to get at the tortoise…
The mortising the foam out idea works real well. That’s how I did mine. Dunno who first came up with the idea, but the first place i saw it was on the North California FREEMO group’s web site. I tried it on a test section and liked it, so I built the rest of the layout the same way.