Mounting tortoise to builders foam

[Ian MacMillan]

My subroadbed consists mostly of 2" pink/blue builders foam. I'm looking to see how others have gone about mounting Tortise switch directly to the foam. 

I was thinking about mounting the machines to 1/8" Masonite, and then using Liquid Nails on nail pins to mount them to the foam.

Whadda you do?

[oakcreekco]

Bingo, that's what I did.

I mounted all my machines "up front", next to the facia, and used RC airplane "control rods" to go from the machines to the switches. They've lasted and work fine.

[ednadolski]

I'm experimenting with those plastic "auger" type drywall anchors in the foam.  The ones I've tried seem to hold fairly well so far.   You can put a few of those into the foam, then fasten the Tortoise with the mounting screws.



A bit better than adhesives, if you ever need to change out the Tortoise.

Ed

[mcjaco]

My Father used masonite glued to the underside of the pink foam with liquid nails, then affixed heavy duty velcro to the masonite and the top of the Tortoise.  He fabricated a linkage, and now he has a motorized turnout for his HO module.  It's not pretty but it works.  Which I think might be his modeling motto.....

[DKS]

My subroadbed consists mostly of 2" pink/blue builders foam. I'm looking to see how others have gone about mounting Tortise switch directly to the foam. 

I was thinking about mounting the machines to 1/8" Masonite, and then using Liquid Nails on nail pins to mount them to the foam.

Whadda you do?

I used to use a rectangle of thin ply, like luan (easier to work than Masonite), glue it to the foam with Liquid Nails for foam, and also sink four long, coarse-thread sheetrock screws through holes in the ply into the foam. This anchors it while the Liquid Nails sets, and also improves the strength of the attachment. The Tortoise is then screwed to the ply, so it's replaceable.

[wm3798]

My subroadbed is a sandwich of 1/4" luan and 3/4" foam.  The Luaun provide some stability, and a mounting base for the various hardware below decks.  I also attach a square of plywood to the switch machine to screw to the bottom, as precisely aligning the throw rod AND hitting those mounting slots accurately while crawling under the layout usually doesn't work out so well.  (I also mounted most of the switch machines while the layout was in the garage, standing on its side where I could easily work with top and bottom at the same time....)

Ed, I don't think those auger anchors would work too well, as once the screw "bites" in, it will quickly torque through the foam.

Oh, and on thicker foam, such as the 2" you're using, you could cut out a trench where the turnout is going to be installed such that a piece of plywood can be set in flush with the foam surface.  That allows you to mount the turnout and the Tortoise at the work bench to assure a precisely centered installation, then just drop it into place, like this:



This guarantees no movement between the switch points and the machine, and gives you some flexibility if you have to tweak the track alignment post installation.  The cork bridges the surface joint to seal it up for ballasting, and the sides can be blended in with your usual scenery materials.

If you use their modular wiring clip, if you have a problem with the turnout or the machine, you just cut the piece out of the scenery, repair, and put it back.  Also, if you go to rebuild a new layout, you can just pop this assembly out, and re-use it all ready to go!  Easy Peasy.  (Woops! Is that trademark infringement?!?)

Lee

[David Leonard]

If I may be permitted to extend this topic a bit (namely through another 2" of foam), does any of you have experience with Tortoise machine installation and operation through a double layer (4½" total) of foam/plywood? I'm building an upper level over the base benchwork and am not sure how to do it. Would the longer wire even have enough tension to move the points? Would I be better off cutting a large hole in the base level platform and adding the second layer of foam over it?

[wm3798]

Dave, see my post just above yours!  You can put that on top of 6 feet of foam.

Lee

[Ian MacMillan]

Thanks everyone, glad to see its working for others.

[DKS]

If I may be permitted to extend this topic a bit (namely through another 2" of foam), does any of you have experience with Tortoise machine installation and operation through a double layer (4½" total) of foam/plywood? I'm building an upper level over the base benchwork and am not sure how to do it. Would the longer wire even have enough tension to move the points? Would I be better off cutting a large hole in the base level platform and adding the second layer of foam over it?

I've gone through nearly a foot of foam, literally. The trick is to change the linkage from a simple wire lever to a rotating rod. The Tortoise is mounted horizontally, instead of vertically, and it rotates a rod that passes up to the surface through a tube, linking to the turnout in a more "traditional" manner (the old "Z linkage" technique).

Lee's method certainly works, but it makes maintenance a real bear, since the Tortoise is then shrouded in a foam hole. This would be even worse for thicker foam layers.

[wm3798]

But foam is very easy to cut out and patch back in.  We're talking scenery here, not cabinetry.  If the foam is that thick, make provision for an access hatch.  And if you have to dig in there too often to fix the machine, you probably did something else terribly wrong.  Those things are virtually bulletproof.

My thinking is that if you have a permanent, solid connection between the machine and the turnout that can be installed under controlled conditions at the work bench, the potential to need maintenance is remote.

This is especially true in the case of a complex interlocking where several machines have to work together, or one machine is working through a linkage.  I'd hate to be up to my elbows in benchwork trying to align everything and wire it, only to find out that something is off by a 16th of an inch, causing the points to behave badly... or that you wired a connection backward...

Lee

[DKS]

But foam is very easy to cut out and patch back in.  We're talking scenery here, not cabinetry... And if you have to dig in there too often to fix the machine, you probably did something else terribly wrong.  Those things are virtually bulletproof.

Hacking up foam in areas of the underside of a large layout can be as difficult as anything else, particularly if the location is inconvenient. Also, using terms like "virtually bulletproof" is a risky thing. The one turnout you think will never have problems is the one that's usually the first to fail. I agree that one may be making some kind of mistake if a machine fails chronically, but it only needs to fail once to become a PITA to service.

Mounting the Tortoise as close as possible to a convenient location simply makes life that much easier, and doing the least to impact the integrity of the layout's structure, like hacking big holes in layers of foam (since the foam may not always be "just scenery"), is simply a better approach.

Of course, a lot of this boils down to personal experiences and preferences. Based on my experiences, making it convenient to get to a switch machine compensates for any small advantages in placing the switch machine right up against a turnout. When you're linking a machine to a turnout, you're still faced with the need to eliminate that 1/16-inch error whether the machine is right under the turnout, or a foot away.

My thinking is that if you have a permanent, solid connection between the machine and the turnout that can be installed under controlled conditions at the work bench, the potential to need maintenance is remote.

This is true, but only for new work. Powering an installed turnout, or making changes to existing trackwork, more or less does away with "controlled conditions."

[David Leonard]

This is great information! I think what I will do, when I get to that point, is put the machine under the layout and go up through the plywood and the 4" of foam. I will have to find a long drill bit to go through all that, the difficulty being to drill truly vertically and not at a slight angle.

If that doesn't work, I'll cut a big hole in the lower level plywood and foam (but not in the bracing!) and leave room enough to work with the upper level machines. This could be OK since all the turnouts on the upper section are adjacent to one another.

[wm3798]

It's more likely that something will get out of whack if there's a bunch of moving parts between the machine and the switch it is to control.  Now granted, David K can engineer an N scale fly with batting wings, so his preference might be to go that route.  Also, when I suggested an access hatch, it would be from above, in the scenery, not from below.  I try to avoid the nether regions of the layout at any opportunity!

For me, I prefer to keep things ultimately simple.  Machine>fulcrom>throwbar is about as complex an equation as this former English major cares to tackle.  For me, the idea of taking the X-acto to 6 square inches of scenery is far more appealing than moving all the schnit out from under the layout and crawling around on my back.

My layout is only 3' deep, so worst case is I'm reaching in about 2' to fix a bit of scenery.  All that other stuff is a bazooka where a fly swatter will work just fine. 

Lee

[DKS]

It sounded as though the original request concerned mounting options from below. If one prefers working from above, then I can recommend it, since that's the route I took for my last N scale layout. All of the Tortoises were mounted above-ground, hidden by structures. The linkage was linear, and was as complicated as a single bent piece of steel wire inside a length of brass tubing.

As for the linkage I described to pass through deep foam, that was not rocket science, either. If someone can install a twin-coil, then they can do this.



Edit: Here's the concept behind the surface mount scheme I used. The Tortoise is mounted in a hole under a building (it could also be just a small piece of removable scenery covering it) such that the moving part is roughly even with the track grade. The wire link is bent into a Z near the Tortoise to permit overtravel. Ultimately, there's only one part more than a traditional Tortoise mount, and that's the tube. Being above-ground, everything is easily accessible.