Foam sheets or foam sheets with plywood?

I have been reading about the various methods used to fasten tortoise switch machines to foam. Wouldn’t it be easier to use 2" foam over 1/4 plywood? The framework of 1 X 4’s could be on greater centers also and you can mount anything you want on the bottom.
What do you think?
BB

Maybe, but I don’t have any problem with mounting them from the top like I do. If something odd comes up other than a basic turnout, I can always glue a square of plywood to the bottom of the foam to mount whatever needs to be screwed on.

If you go to bottom mounting on plywood under 2" of foam, you’ll need to replace the stock wire with something thicker so it moves the points instead of just bends.

I am pretty confident I could go to 24" centers on my benchwork and still support the 2" foam adequately.

–Randy

Thanks Randy,
When you mount the Tortois from the top, would you need to remove the turnout in the event of a malfunction of the Tortois?
BB

You probably would, BB, as I’ve seen pics of Randy’s method and he is flushmounting the Tortoise machines to the top of the foam (the Tortoise machines are mounted on PC board and it is the PC board which is flu***o the foam surface) but then again, when do these switch machines ever go wrong?

I plan on using this method as I have decided to go totally without plywood (or homasote) and my foam will be 4" in some places so I think I have to surface mount them.

-Dave

Yes, you do - but it’s not a problem. I slide back the joiners at each leg of the turnout and lift it off. Two slices throughthe roadbed at either side of the Trotise mount and it pops right out.

I’ve already pulled 2 out and relocated them, I changed my mind on the track plan after having them in place. But at the club I belonged to we had over 100 Tortoises and never had one fail. I think there’s a far greater chance of me having to tear down the entire layout and moving than for one of the Tortoises to fail. As my wife has made clear, this is not our ‘final’ house, after my in-laws are no longer with us this house will be much too large. Since we will both be older, I’m hoping at that point that the ‘final’ house will be a single-story design with a full basement - end up beign a small house but a bigger basement. But you never know.

–Randy

I would do the foam with ply myself… but then agian I might only use 1/8 ply because it’s smaller and lighter.