# Atlas under table switch machine mounting problem



## Zug (May 4, 2012)

I've got to the point I want to start mounting my Atlas under table switch machines on the new layout, both the metal pin type with the switch contacts and the type the have just the plastic pin and no switching connection for other stuff. All have been used on previous layouts and the pins were cut for 3/8" plywood plus road bed. 

the problem is when I bought the plywood for this layout I got 1/4" instead, and yes now I'm thinking I went too thin, but I got too much done to want to start over...

I don't want to cut the pins on the switch machines any shorter, so at this point I'm think popsicle sticks as spacers, 2 or 3 thick seem to be about right and gluing some together right now. Then will cut them shorter so one block under each end of the switch machine.. and since the screws won't work right now. I'm thinking silicon glue the wood to the switch machine, then once that dries, hot glue the wood blocks to the plywood. So that would leave then removable by separating the machine from the silicon when the need arises..

And being a make shift fix, I was wondering of anybody had any better ideas to mount these switch machine with out cutting the throw pin any shorter?


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## traction fan (Oct 5, 2014)

*Popsicle sticks*



Zug said:


> I've got to the point I want to start mounting my Atlas under table switch machines on the new layout, both the metal pin type with the switch contacts and the type the have just the plastic pin and no switching connection for other stuff. All have been used on previous layouts and the pins were cut for 3/8" plywood plus road bed.
> 
> the problem is when I bought the plywood for this layout I got 1/4" instead, and yes now I'm thinking I went too thin, but I got too much done to want to start over...
> 
> ...


Zug;

Your idea of shimming down 1/8" to get back to your old 3/8" thickness is good. I advise you to use pieces of 1/8" thick MDF or Masonite, instead of Popsicle sticks. The sticks split very easily. Even if you don't drill through them and use screws, they're semi-brittle, and will get more so over time. The MDF or Masonite are a lot more stable. No sense in mounting the machines and then having to do it over again later.
The 1/4" thick plywood will be somewhat more inclined to warp than thicker stock. It can work well though. Plenty of L-girder shaped bracing, and a coat of exterior house paint to seal the wood will help prevent warping. The L-girders don't need to be the massive 1x4 and 1x3
versions that were used back when. I've used 1/4" Luan plywood braced with 1"x 1/4" lath boards. Works fine. The L shape is impossible to bend in any size. Enough force can break it, but not bend it. That's why it's so good at keeping even thin plywood straight.

regards;

Traction Fan:smilie_daumenpos:


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## Zug (May 4, 2012)

I was thinking about using left over 1/4" plywood from the board I bought if that worked.. the popclycle sticks are just convent.. 

the layout itsself is two 2' by 4' sections each with 1" by 3" boards on the front and back and ends screwed and glued, standing on six 2" by 4" legs. so it's already pretty strong. but I'll see where I can add extra braces after the switch machines are in place. I also discovered there's a hazard to using thin wood.. Atlas track nails poke out the bottom..


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## CTValleyRR (Jul 26, 2014)

I agree that your approach is the correct one. It really doesn't matter what you use for a shim -- plywood, basswood, styrene, popsicle sticks, etc, -- as long as you can mount it.

Personally, I use double-sided foam tape to mount servos under the layout.


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## tr1 (Mar 9, 2013)

*Are Under the table switch motors for turnouts really that unreliable?*

would a little graphite in the correct spaces for easy movement help?
Would a "capacitor discharge unit" help give the "switch motor" a good jolt of volts to work? 
Would a aluminum tube placed over the plastic shaft possibly work?
(I'm sure some minor alterations or combination of alterations of that will eventually work!?
Good luck with your current dilemma there
I'll try to stay in the loop.
Regards,tr1


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## traction fan (Oct 5, 2014)

*Under the Table*



tr1 said:


> would a little graphite in the correct spaces for easy movement help?
> Would a "capacitor discharge unit" help give the "switch motor" a good jolt of volts to work?
> Would a aluminum tube placed over the plastic shaft possibly work?
> (I'm sure some minor alterations or combination of alterations of that will eventually work!?
> ...


tr1;

Done correctly the motor should work just as well under the table as on top. The Atlas twin coil switch machine is very weak, compared to other switch machines, either twin coil like Peco, or DC stall motor like tortoise. Yes a capacitive discharge unit will help snap the points over a bit better. Perhaps more importantly, the CD unit will prevent meltdown of the Atlas twin coil machine if a button is held a second too long, or shorts. 

regards;

Traction Fan:smilie_daumenpos:


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