Would I be able to find any motor that could be made to work through 2" of foam + 1/4" plywood or even up to 2" + 1/2" plywood ?
Or how about a surface mount motor for the Walthers/Shinohara curved switches.
A Tortoise machine comes with a wire that’s intended to go up through the subroadbed and roadbed and through the small hole in the throwbar between the points. The wire they give you won’t make it through 2 inches of foam, but you can go to that hardware store and get “music wire” for very little money, and cut and bend it to shape.
The Tortoise has an adjustable pivot point, which lets you control how far the top of the throw wire moves as the motor traverses.
I have 2 inche foam and 1/4 inch roadbed. I glue a piece of 1/4 inch plywood to the bottom of the foam, and attach the Tortoise to that. No problem. I’d guess that I could add another inch or even two and it would still work fine.
A Tortoise will work fine. On my previous layout I had 2" of foam, but no plywood. I mounted most of my Tortoises from the top - see the ‘old stuff’ part of my web site. I did try a couple on the bottom - worked fine.
My current layout has 2 layers of 2" foam plus 1/4" plywood ont he bottom, total 4.25" thick from the bottom to the top, plus the thickness of the cork roadbed. I am using servo motors this time, and they work fine through all that. I have to check but I believe my music wire is .032". I have no problem but I also am using Atlas turnouts which move very freely. Handlaid all-rail turnouts would be stiffer and harder to move but also would not need to move as far to close the points on either side.
–Randy
As others have advised, a Tortoise will work fine through thick foam if you use a longer throw wire. Another option is a Switch Master slow motion motor, that also sold under the brand name of Torque Master.
The Micro-Mark Switch Tender has not received favorable reviews.
If you use an Anderson link, the vertical thickness of what’s between the throwbar and the bottomof the subgrade is limited only by the length of the available drills, metal tubing and bendable wire. Also, any switch machine (or manual throw) can be used - just as long as it can be linked to the under-plywood arm of the Anderson link.
What’s an Anderson link? In its simplest form, it’s a more-or-less Z-shaped wire running through a vertical piece of small-diameter tubing. The top arm of the Z has a hook end, inserted through a hole in the throwbar. The bottom arm (which can be at any angle - it doesn’t have to be opposite the top arm) is connected to the switch-moving mechanism. The vertical portion, inside the vertical tube, transmits rotary motion. I have turnouts with Anderson linkages driven by RIX and KTM twin-coil machines and by manual throws made from toggle and slide switches. They all work.
In HO, the top arm should be about 1/2 inch long. The length of the bottom arm is somewhat dependent on the throw of whatever is powering it, allowing for the ‘slop’ of the wire in the tube and the inherent springiness of the design. Mine vary - the shortest for slide switch mechanisms that throw 1/4 inch, the longest for my ancient KTM rocksmashers with their 15mm throws.
There is no reason why Tortoise machines can’t operate through Anderson links. In the future I may have to figure out how to make them work.
Chuck (Modeling Central Japan in September, 1964)
I use Tortoise under 1/2 inch of plywood, about an inch of foam and cork roadbed. The manufacturer recommends increasing the size of the wire between the switch machine and switch. I use .032. I think the default would have worked fine but they are the expert.
There are several sites I’ve come across showing a Tortoise using an Anderson link. And their own Remote Mount uses it, moving the underside part fo the link via a flexible cable which allows you to place the bulk of the Tortoise elsewhere in case of clearance issues. I WAS going to just go with Tortoises like before until I came across the servo controllers from Tam Valley, so I bought one of the remote mounts to see how they did it so I could duplicate the rest myself.
–Randy
Thanks for all the tips, gentlemen. I ordered some tortoises now for the three expensive curved switches I had to incorporate. I would have tried tortoises with all the new switches on the layout had the expense not been so great (and I have a lot of cross bracing in the way under the benchwork as it turns out).
At $19.95 ea. tortoise motors for the expansion section would have come to $518 so I continued with the Atlas motors on the rest.