Switch Machines on Foam

[Anonymous]

A few issues back in RMC an article mentioned not to attach switch machines directly to foam cause the pressure would pull things loose. Is this advice only for constant power machines like Tortoise? Is there any problem attaching Atlas under table machines for code 55 directly to foam?

Regards,
Mo

[rrinker]

I think it would be even worse witht he Atlas motors, because of the snap action of the solenoids. You might be able to do with them what I did with my Tortoises. I mount the Tortoise on a square of PC board material (since it has all those nice holes already drilled in it) and then cut a recess int he top of the foam with a router bit on the Dremel.The center part I cut out with a knife. I drop the Tortoise in from the top and then lay roadbed and put the track on.
I recall seeing a similar application for Atlas machines, in which the roadbed and a thin piece of palstic were glues tot he bottom of the turnout,a nd then the machine fastedn on. A recess carved in the foam then fits the machine. I have a lot of old Model Railroaders, so I'm not sure when this was - you might try the MR Index, I believe the article title was soething like "Unitized Switch Machines" or something to that effect.

--Randy

[johncolley]

another method uses a small square say 3"x3" of 1/4" plywood glued to the bottom of the foam with Liquid Nails project adhesive for Foam. The Tortoise will be screwed to the plywood. Center the throw and the turnout points during installation. I pre-drill the plywood for the mounting screws. Another hint...use a small 2 slot terminal block from Radio Shack or auto/hardware store and crimp spade connectors on the leads and control connections, you won't be sorry if you ever have to change it.

[northern_blues]

I guess depending on how deep your foam is, one method may work better than another. routing out and dropping in from the top would work no matter how deep the foam.

I don't have PC boards laying around. I do have 1/8 " masonite that I could slice up and mount the switch to as per Randy's method and then route out the top of the foam to flush fit. Seems pretty tidy way to go.

-Dave

[Anonymous]

Hmm, pegboard would provide convenient holes too.

--Mo

[rrinker]

Holes in pegboard are a bit large. The holes in the perfboard are a bit small so I drill them out to better fit a 2-56 self tapping screw, this is what holds the Tortoise in place. I did the first half dozen by hand, all the while staring at the Dremel with speed control. Then I woke up and stuck the drill bit in the Dremel and did the rest with a power tool. DOH!
Thin masonite would work, although even the thinnest masonite is twice as thick as the perfboard. Sheet styrene would work great as well. The originators of this technique are some guys from the NorthBay (California) Freemo modular group. They used squares of copper clad PC board, and drilled holes for the Tortoise mounting screws in those.

--Randy