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Atlas Switch Machine Conversion

When I decided to install Under-Table switch machines on twelve of the turnouts/switches on the BRVRR I was facing a considerable expenditure. I considered Tortoise machines, but they were out of reach financially at the time. There had to be a way to use what I already had to accomplish the job. The short photo-essay below illustrates how I converted Standard Atlas Remote Switch Machines to Under-Table Machines.

Standard SWM

The starting point is a standard Atlas Remote Switch Machine. This one happens to be a 'Left' hand machine, but the conversion will work on either 'Right' or 'Left' machines. Once converted the machines are usable in any position under the layout.

SWM Tools

The only materials needed for the conversion are a standard remote switch machine, some fast curing epoxy, a length of 1/8-inch styrene tubing and a short length of stiff wire. I used part of a large paper clip for my wire.


The first step is to cut a piece of wire about 1-inch long. Then cut a 1-inch long piece of the 1/8 tubing. Heat the center of the tubing for a few seconds (I use a small lighter for this) and bend it into a 90-degree elbow shape. Mix a small amount of the quick-cure epoxy. Apply some epoxy to both ends of the tubing elbow. Insert the actuating rod of the switch machine into one side of the elbow until it is about 1/8 of an inch away from the switch machine housing. Insert the 1-inch piece of wire into the other side of the elbow, all the way down to the turn. I allow the epoxy to 'set-up' long enough to make it very tacky. I then I put the whole switch machine assembly on the edge of the workbench with the wire hanging down while the epoxy fully cures. Gravity will ensure that the wire is 90-degrees to the axis of the switch machine, unless you waited too long for the epoxy to become 'tacky'. Small adjustments may be necessary to get the alignment or position you want between the components.


This is top a view of a converted switch machine.

SWM Bottom

This is the bottom view. This is the side which will face the underside of your layout.


At the top of the photo is a 'factory built' Atlas Under-Table Switch Machine. At bottom is the Standard Atlas Switch Machine converted to under table use. While not as 'pretty' as the factory made machine, these converted units are every bit as effective and reliable as the Atlas factory made machines.


This is a photograph of one of my converted machines mounted under the layout. This particular machine operates the turnout/switch at the southwest end of my reverse loop. The hole in the table is 1/2-inch in diameter and centered between the rails under the throw bar. The wire operating rod extension goes up through the table and into the hole in the center of the turnout's throw bar. I mount my machines with 1/8-inch thick double-backed, tape. It allows for minor adjustments for alignment and seems to hold well. Once you are satisfied with the operation, trim the length of the wire to prevent interference with the trains, about 1/16-inch or so above the throw bar seems to work okay.

I have used these converted switch machines on the BRVRR for nearly two years without a failure. I had one melt when my grandson 'leaned' on the actuating switch too long, but never a mechanical failure. As I said, I mount my machines with double-backed tape, you may prefer another, more positive, method. I've only had one machine come loose in two years.

I have had several requests about my methodology for conversion. I hope this little photo essay helps.

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Copyright by Allan Coates 2004-2016. All Rights Reserved.