Re: Mounting Tortoise Machine through Foam

Russ Norris

Gotcha!  Although I have not found this to be a problem on my layout (I do use a heavier gauge wire and this seems to prevent your problem) I understand what you are saying.  On a wye I once tried to use a Switchmaster instead of a Tortoise.  The advantage of the Switchmaster is that the action is not back and forth (as in the case of the Tortoise) but circular.  The wire is turned by the machine, and the torque is transmitted through a length of brass tubing to the throwbar on top.  This works great if your layout is constructed of plywood and Homosote.  I tried it with 2 inch foam and found that the brass tube tended to wiggle as the wire rotated, and eventually the tube gouged out a larger hole in the foam, making the entire link fail.   I don't know of any way to overcome this except possibly having the tube go through small squares of wood on the underside and top of the foam, the wood being glued to the foam so it can't move.  I haven't tried this technique, but it seems plausible.  

The other possible solutions involve surface mounting the switch machine and disguising it in some way -- either inside scenery or in a building adjacent to the track.  In that case, you would still be dealing with a back and forth motion, not a circular one.  All of this has convinced me that plywood and Homosote are the way to go for benchwork.  Foam is great for scenery, but it has several negative aspects.  First, of course, is the difficulty in mounting switch machines.  The other problem with foam is that it's noisy.  When one of my brass engines travels over foam, the grinding of the gears is amplified into a rumble that can be hear some distance away.  When the engine passes over an area where I used plywood and Homosote, the noise disappears.  At my age, I don't think I will be building another layout, but if I did, I would not use foam.

Russ Norris

On Mon, Jan 21, 2019 at 9:53 AM asandrini <asandrini@...> wrote:
Russ, and others...

It us not the actual mounting of the machine, it is the working of the machines with an extra length wire from below. 

With the long travel of the wire, the timing of having the points releasing from the stock rail and the switching if polarity of the frog could and in most cases will create a short.  If the fulcrum is mounted in typical disrance/position beneath the subroadbed, there is no problem.

Even Ciruitron warns of this problem.


Sent via the Samsung Galaxy S7, an AT&T 4G LTE smartphone

-------- Original message --------
From: Russ Norris <rbnorrisjr@...>
Date: 1/21/19 6:19 AM (GMT-08:00)
Subject: Re: [HOn3] Mounting Tortoise Machine through Foam

The substrate for my HO scale railroad is 2 inch extruded foam (the pink stuff) on an open grid of pine 1x4s.  I have tried several ways to mount Tortoise machines.  Early on I cut a hole in the foam big enough for the Tortoise to fit in.  Then I cut a square of wood or styrene slightly bigger than the hole (1/8 or 1/16 inch thick as I recall) and screwed the machine to it.  I cut away 1/8" off  the top of the foam so the Tortoise fit even with the top of the foam.  A little glue to secure it, then I just lay the switch over it.

Later I found it was easier (especially retro fitting the switch machine for an installed and ballasted track) to mount the machine under the foam.  I still attach it to a 1/8" square of thin plywood, but now I drill a 1/2" hole under the throw rod and cement the wood square to the underside with Liquid Nails.  I use a wood pole and shims to hold the machine in place until the glue dries.  Never had one come loose.  If I ever have to remove the machine, I can unscrew it from below.  

Oh, and by the way, I am 77.  I use one of those adjustable shower stools to sit on when I work underneath.

Russ Norris

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: asandrini <asandrini@...>
Date: 1/20/19 11:52 PM (GMT-05:00)
Subject: [HOn3] Mounting Tortoise Machine through Foam


Sorry for the multiple listings, but I am trying to reach as many modelers
as possible to see if there is an answer to my problem.

In the construction of my port town of Scott's Bay, I used 2" form on ½"
plywood.  As a river, the bay and wharf areas were to be lower than ground
level, I thought it would be easier to cut it out of the pink foam.  My
conundrum is that I cannot mount Tortoise machines in their normal manner.
I purchased some of their remote mounts, but my 71 year old knees are having
trouble kneeling down and trying to fit everything together under the bottom
of the benchwork (40" in height, track is at 42 7/8" ).  I would like to use
the Tortoise machine to move a wire that rises through a tube two ties from
the throwbar.  The wire would be bent at 90 degrees and then another bend of
90 degrees to drop it down through the throwbar.

What I am wanting to do is mount the Tortoise in its normal manner and have
the wire which attaches to the machine move the wire that moves the
throwbar.  I am sure that someone out there has come up with a way to do

My crude drawing attached is a way in which I think may work, but am needing
some help from the groups.

I am going to try to embed the drawing here, but will also add it as an


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