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  • Switch It


    1. This stubby switch stand is typical of the types the real railroads use to throw their track switches from a mainline route to a siding. This particular unit is bolted together from angle iron and castings. Both Kemtron and Alexander make similar units in HO scale.

    2. This type of switch control stand is assembled from a basic iron casting. Again, the HO modeler can obtain similar units from either Alexander or Kemtron. Switch stands like these can be quickly fabricated from plastic or brass scraps to add realism to your track work.

    3. Few modelers bother to try to duplicate all of the intricate castings, spikes, and bolts that are part of every full-size switch. Most of these parts can be made from scraps of brass or plastic, for a model railroad, to give the appearance of fully-detailed track work.

    4. ConCor's $2.75 switch machine has adequate power for use in controlling N, HO, or 0 scale track switches. The round coil is energized by a quick burst of 16 volt A.C. electrical current to move the plunger inside which, in turn, flips the spring-loaded arm at the right for positive throw of the switch's points. The hairpin spring is used in the linkage between the switch machine and the track switch to compensate for any variation in the amount of required throw.

    5. The major advantage to using switch machines (besides the fact that they provide the means for remote electrical control of the track switches) is that they can be mounted completely out of sight beneath the layout. For this type of upside down mounting the corner of the ConCor machine should be clipped away with diagonal cutters.

    1001 Model Railroading Ideas - Fall 1971 - Page 25 1001 Model Railroading Ideas - Fall 1971 - Page 26

    The track switches that are used most model railroads are almost identical, in both performance and operation, to those on the real railroads -- there are, after all, only so many ways you can divert the path of the car's and locomotjve's flanged wheels from a straight track to curve out to a siding. There are, however, many different ways of actuating the model switch. Some of the ready-to-Iay switches have a small lever beside the rail that you have to throw by hand to divert the rails from the main line to the siding. Others have a small plastic box beside the rails that contains a solenoid that has to be actuated electrically by pushing a button on a switch control panel that is (usually) furnished with the switch. Both of these systems are fine for a first layout and their instructions are adequately illustrated and detailed to allow you to connect them to the rest of your trackage and, in the case of the remote controlled switch, to your control panel. The appearance of both types of switches, in either HO or 0 scales, leaves something to be desired. Brands like Tyco, AHM, Atlas, or TruScale are designed to get your railroad operating as quickly as possible with as great a degree of realism as can be encorporated in a ready-to-work switch. The more experienced model railroaders usually prefer to lay their own rail; spiking it to individual wood ties, or to use the track components supplied by Lambert Associates for HO scale. These modelers are then able to have rail and ties that are far closer to what the prototype rail would look like if scaled down to HO or 0 scale dimensions - the rail on most other brands is about 50 percent oversize and the ties are often spaced a bit further a part than they should be. The problem with using hand-laid ties and rail or the Lambert-brand pre-fabricated track is that there is no provision whatsoever for actuating the track's switches; either manually or for remote con trolled electrical operation. The black plastic boxes beside the Atlas, Tyco , AHM, and TruScale brands of ready-to-lay track perform the same function as the ConCor unit shown in the photos; both are called "switch machines" because they are the machines that actuate the track switches. Units similar to the ConCor switch machine are available from Lambert, TruScale, Balboa, Walthers, and PFM. They range in price from $2.00 to $3.00 and all include (or have optional) electrical contacts that are moved with the track switch movement for operating signals or to be connected to the rails so the contacts, rather the points of the track switch, carry the electrical current to the rails beyond the track switch.


    6. & 7. The hairpin spring can now be inserted in the end of the switch machine's spring-loaded bell crank as shown and the protruding end bent over at a slight angle so the hairpin spring cannot slip out of the linkage. Make the bend about 1/8-inch below the bel/crank hole so there will be no chance for the hairpin spring to work halfway out and bind.

    8. The ConCor switch machine (and similar units from PFM and Kemtron) has two sets of contact points that are operated each time the unit is energized to throw the track switch. Wires can be connected from these contacts to the track rails above to insure a positive flow of electricity to whichever route the track switch is aligned. The second set of contacts can be used to activate the light bulbs in trackside signal lights or to energize relays for automatic operation.

    9. & 10. Solder one-foot lengths of #18 or #20 gauge insulated solid copper wire to the three power connections on the switch machine's solenoid coil and then to the contact points before installing the machine - you could connect these wires after the machine is in place but it's far easier to work on the benchtop than to try to solder under the tabletop.

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    You can purchase the switch machines for the Atlas, AHM, TruScale, or Tyco switches for considerably less money but the machines themselves don't have the power or reliability of the $3.00 items and they lack the separate electrical contacts. If you are using Lambert's scale rail plastic track or hand spiking rail to individual ties we would recommend using one of the ConCor, Lambert, TruScale, Balboa, Walthers, or PFM switch machines for remote control switch operation. Any of the six brands of quality switch machines can be mounted on top of the table beside the switch or, as shown in the photos, under the table and out of sight. One of the better reasons for using these switch machines in the first place is to be able to have the switch control hidden rather than sitting up beside each switch to mar the realism of your miniature railroad. The problem is, though, that none of these switch machines are furnished with the type of linkage you need to reach under the table. Most have a hairpin spring to transfer the power from the switch machine's lever to whatever linkage you can buy or devise - the hairpin spring will work just fine if the switch machine is mounted on the tabletop beside the track switch. Both Earl Eshleman and Kemtron have a type of link like that shown in the photos and most well-stocked model railroad shops carry one or both brands.


    11. & 12. You'll need a V-shaped link to be moved (at its lower end) by the switch machine so the upper leg of the "V" can move the throw rod between the track switch's point rails. You can fabricate your own from a piece of .020inch steel piano wire with a brass tubing bushing through the tabletop but the wire will be difficult to adjust properly. Earl Eshleman and Kemtron market switch linkages that are adjustable at one end to simplify final adjustment. A hole must be drilled in the tabletop beside the track switch to accept the bushing from the linkage kit. The elbow-shaped link is then dropped in place inside the bushing. It is most important that the distance between the center of the bush ing hole and the mounting hole in the extended end of the switch's throw rod exactly match the distance between the mounting hole and rod of the elbow linkage. The Eshleman and Kemtron links are attached to the end of the track switch's throw rod with a small screw. The screw should be just loose enough to aI/ow the link to pivot. Be sure the link swings freely, from one throw of the track switch points to the other, before in stalling the bottom half of the link or the switch machine.

    13. & 14. Clamp the bottom half of the link to align with the top half's arm and then position the switch machine so it will align with the arm when the machine's spring-loaded bel/crank and the track switch's points are thrown in the same direction. Mark the location of the switch machine by pricking holes into the bottom side of the table through the machine's mounting holes. You can leave the icepick or awl punch in place in the final hole to hold the machine while you insert its attaching woodscrews.

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    You can obtain the Eshleman unit by mail from Earl at Elizabethtown, Pennsylvania 17022. Send a stamped, self addressed envelope for his latest catalog and price list. The Eshleman and Kemtron turnout links are available in a variety of sizes to match the thick ness of the baseboard beneath your track; most sizes sell for a dollar or 30 more. The photos and captions describe the installation of the ConCor switch machine and the Eshleman link age but the procedure and general steps would be the same for any of the brands listed. The wires that lead from the switch machine should connect to the 16 volt A.C. posts on any standard model railroad power pack and to a pair of Kadee or similar doorbell-type pushbuttons at your control panel. The only advantage to using the Kadee pushbuttons is that they are about the smallest you can buy so they can be worked right into a track plan and switch diagram on the control panel for easy identification.


    15. & 16. There is very little movement in the bottom half of the linkage or at the switch machine's spring-loaded bellcrank but it will be more than enough to firmly snap the track switch's points from the straight ahead to the curved side of the switch as the switch machine is moved. The spring, switch linkage, and bel/crank should align as shown in these two photographs. Adjust the tension on the point rails of the track switch by loosening the clamp-on bottom half of the link and moving it until the tension is equal with the switch thrown in either "straight" or "siding" positions.

    17. The completed switch machine and linkage are barely visible beside the track switch. Once you are sure the unit is operating correctly manually you can connect the wires to pushbuttons on your control panel and to the 10 to 16 volt A.C. power supply terminals on your power pack. Small nails can be driven into the bottom side of the table to serve as soldering posts to connect the short wires you soldered to the switch machine to the wires leading to push buttons and power supply.

    18. This PFM (Tenshodo) switch machine was installed exactly like the ConCor unit in the other photos. The edge of the track will be covered over with scenery later to completely hide the switch machine from normal viewing. It's best to have all of your switch machines in stalled and opera ting correctly before starting on the scenery that might make the switch machines harder to see and reach.

    1001 Model Railroading Ideas - Fall 1971 - Page 31 1001 Model Railroading Ideas - Fall 1971 - Page 32

    Each of the switch machines is furnished with a wiring diagram to show just where each wire should be connected from the machine to the pushbuttons or power pack. Tri-Delt Electronics, Box 203 11, San Diego, Calif. 92120, and others offer a special capacitor discharge type of power supply that is perfect for actuating switch machines. With a normal power pack and push button, too long a pressure on the pushbutton can allow the switch ma chine to overheat and burnout. The Tri-Delt unit allows only a single snap of power to give positive throw to the switch machine no matter how long you lean on the pushbutton. The Tri-Delt unit sells for $12.00 and will operate any of the popular brands of switch machines and it can be used with Kadee or any other type of pushbutton.

    Once you've installed an under-the-table switch machine you may want to provide some sort of simulated manual switch control to match the appearance of the switch stands that appear beside most of the full-size railroad's switches. All that is required is a duplicate of the switch stand standing on the two extended ties beside the switch's points. You can fabricate your own from brass or plastic scraps to match the style used by the rail roads in your area or to match one of the two styles shown in the photos. Your local model railroad dealer should be able to supply a Kemtron or Alexander-brand switch stand that is fully-detailed and ready to paint and glue or spike in place beside the track. Once you've gone to the trouble of providing hidden remote control switch actuation you might just as well make your switches look as realistic as the real thing.

    Article Details

    • Original Author 1001 Model Railroading Ideas
    • Source 1001 Model Railroading Ideas
    • Publication Date Fall 1971

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