Turnouts on foam

[2021]

I'm considering building my new layout (15' x 20') using 2" foam board over 1/2" plywood. I would like to use Tortoise switches for the turnouts but am concerned about the arm length when I mount the switch under the plywood. Has anyone out there made such an installation and how effective was it? I would welcome any suggestions.

[Anonymous]

not sure but would it be possible to cut away enough of the foam and just put it in the foam?

[ndbprr]

Not having used foam I am talking somewhat theoretically but I have visited several web sites for info. Your plywood is redundant. Best way to do it I have found is to box in the foam with a 1x4 frame and 1x4 support pieces about every two feet. That protects the edges, supports the foam and gives you someting to mount a fascia on. switch machines are mounted using liquid nails to glue a piece of paneling or 1/4 plywood to the bottom of the foam so it can be adjusted. Longer linkages do not appear to be a problem with machines like the tortise. Just make sure there is adequate clearance in the hole. I plan to experiment first.

[rrinker]

I am really interested in the methods used by Brian Kreimendahl and the North Coast Freemo group, in which the Tortoise is mounted to a piece of perfboard and mounted into a recess in the foam from the top. I have link to a site with pictures, but it's in a Sony Imagestation gallery and you have to sign up to view them. Anyway, I haven't found too much descriptive text on the method, and I've been wondering how to get the uniform depth to fit the perfboard - router attachment on a Dremel? Using this method, there is no problem with the throwbar ont he Tortoise, the length only has to pass through the perfboard (about 1/16") and the roadbed (cork in the example, and also what I am using). No need for an extra-heavy duty piece of music wire, the piece that comes with the Tortoise would be more than sufficient (in HO or N, anyway). Access is simple enough, push back the joiners and lift the turnout and machine right off the layout, although how often you'd actually have to do this I don't know, the Tortoise machines are EXTREMELY reliable. Never had one fail in the club I used to belong to, and the ones I've used in the past still soldier on. Curiosity got the better of me so I voided the warranty on one and opened it up (multiple times) and have generally abused it, yet it still works smoothly and quietly.

--Randy

[ndbprr]

Why not cut out a plug from 1" foam then use it it as a pattern to cut out the entire 2" foam area where it will go so there is a hole there. Then glue the plug to a piece of paneling or 1/4" plywood and glue it in from the bottom. It should be level and smooth that way.

[rrinker]

Now that's a good idea. Although I probably could do the same by cutting out a piece of the 2" foam and then cutting it in half to make 2 pieces approximately 1" thick. The exact thickness of the plug piece really shouldn't matter . Actually, there's probably no reason to make it thinner, the connections on the Tortoise are more than 2" from the top edge.
That's not the way the original people did it, but it should work, I'll have to try it. Alternately I could probably make a hot wire cutter that cuts out the block (and center hole).

--Randy

[2021]

Thanks for the info. You have given me several methods to try off the layout to see how it works. Interesting comment from ndbprr re the redundancy of plywood under foam. I've heard this before but am a little concerned if I apply weight when trying to make repairs or pick-up a derailed car. Also would you also not put plwood under the main double line (excuse the grammer)?
From 2021 a.k.a. Ron (that name was taken)

[rrinker]

Well, I have all my benchwork up, nothing on tp yet. And it's just 2" foam on top of 1x4's. I wouldn;t concentrate my weight in one spot, but I've leaned on it with no problems. I'm pretty sure I could lay down on top of it and it would easily hold my weight and I'm not exactly a skinny guy). The pink foam from Owens-Corning is rated in I think PSI, ie the Fomular 250 (which is what Home Depot had) is good to 250 PSI. It's on their web site. They have an even stronger stuff which is intended to be used as concrete forms (so you KNOW it can take a lot of pressure) but you'd have to go to a specialty deale plus I doubt the extra cost is really needed. If I can find it, I'd like to use the Fomular 150 stuff for sceneray, plenty strong and I would suspect cheaper than the 250.

--Randy