Some Simple Switch Machine Solutions

Mounting Tortoise Switch Machines

The problem with attaching the Tortoise machines is that the built-in mounting ears are too close to the machine to reach easily with a screwdriver. Plus the machine is small and it's hard to position it critically and drive the screws without pushing the machine out of place. Some vendors sell mounting plates for the Tortoise, however there is an easier and less expensive solution. To alleviate these problems attach each Tortoise machine to a scrap of plywood. The size of the plywood is not important so long as it extends well past the machine proper. The plywood is, in turn, mounted to the underside of the layout. The plywood forms a 'handle' that makes it easy to position and screw the machine in place without movement.

These photos should be self-explanatory.











You'll notice in the pictures above that the actuation mechanism of the Tortoise machine simply extends past one edge of the plywood mounting plate. In this way it is not necessary to drill a hole for the actuation wire through the mounting plate. Also note that I have pre-drilled and countersunk holes for the mounting screws. Four holes are not really necessary, but it provides some flexibility in where the mounting screws will be driven. Depending on your track construction the combined thickness of the mounting plate, subroadbed (plywood) and roadbed can exceed 1". This would be too thick if you use the music wire actuator that comes with the Tortoise. If this is the case cut another wire actuator and make it longer; the Tortoise instructions include a template for the actuator.

Mounting Servos as Switch Machines

Mounting radio-control servos for use as switch machines presents a problem. Some manufacturers sell mounting plate for servos but, as far as I have been able to determine, only for the miniature/micro servos. If you want to use the full-size servos or you need a lot of these mounting plates they are not a solution. There is a simpler and less expensive solution, glue the servo to a right angle bracket sold in home centers for building decks.





The bracket is Simpson 'Strong Tie' A21Z, note: this is the right angle bracket with one arm longer than the other, that's the arm that the servo is glued to. I used Gorilla Glue to attach the servo. I roughed-up the bracket and servo with sandpaper before I dampened the bracket with water and applied a THIN coat of the glue to the servo, then clamped the two together. Use a thin coat, otherwise the glue will foam up all over the work.

Here's the servo switch machine installed:



The machine can be installed above the table as well which is handy in areas of hidden trackage as the machine is easy to access for adjustment or replacement.



The servo switch machine is mounted on a scrap of 1x2 lumber (actual 3/4" x 1 1/2") to provide some height and thereby additional throw for the actuator wire. Notice that the PC Tie throw bar has been extended with another length of PC tie soldered on so that the switch machine can be mounted far enough to the side to clear rolling stock. The extended throw bar is supported by a wooden tie to prevent the throw bar from sagging.

For fitting the actuator arm, made of music wire, to the servo crank I came up with what I think is a novel solution which you can see here:



I bent a length of wire into the shape above. The length of the straight section to the right should be enough to reach up through the subroadbed, roadbed and through the throw bar on your turnout. If in doubt, make it longer, any excess can be cut off after installation. The form of the wire on the other end is shown in the detail close up here:



The distance between the bends should match the hole spacing on two opposite arms of the servo crank so that it fits like this:





In case it's not obvious how to get the bent wire into the servo crank, here's a short video on how it's done:



The self-retention feature that you see in the video works because I am using relatively stiff 0.039 wire as a actuation arm. That allows the right angle bend at the end to exert enough outward pressure to hold the arm in place. If you use significantly thinner wire this might not be the case.

Installing a DCC Decoder in a Diesel Step-by-Step

Installing a DCC non-sound decoder in an O scale diesel "B" unit is about as easy as it gets, this side of 'plug and play.' There are no lights or sound to hook up and there is plenty of room in the wide-body. Click on any photo for a larger view and don't forget to view the videos at the end of the post.

Here we're ready to start, the body's off the chassis of the Weaver diesel and the decoder, a Lenz LE1835W, is at hand.



The LE1835W is an HO decoder, albeit a robust one with a 1.8 amp continuous output.

Here the leads from the left and right rails have been snipped at the motor terminals.



The two feeders from the right rail have been joined with a short length of red wire per the DCC color code for the right rail.



The red wire is connected to the red wire from the decoder and both solder joints have been insulated with heat-shrink tubing. Similarly the left rail leads have been attached to a black wire that has been connected to the black wire from the decoder.



The orange and gray leads have been soldered directly onto the motor terminals (orange to terminal 1, gray to terminal 2) and insulated with heat shrink. This could have been a tighter installation but I deliberately left the wires from the decoder full length in case I ever want to replace this decoder and reuse it elsewhere, I'll have long wires to work with. Therefore all of the excess wire along with the function outputs have been dressed with a cable tie. Finally the decoder has been attached to the weight with double stick tape.



Here's the chassis on the layout ready for a test.



Test run:



Here's the full installation video. Click on the "HD" on the play bar only if you have a fast computer (dual core processor and good video card) and a fast internet connection.

Laying Flextrack

Here's video clinic on laying flextrack. Although it's done in O scale, the techniques are directly applicable to any scale where flextrack is available.

Because it was recorded over five months, there are some continuity errors, mostly in the form of some repetition and one segment that had to be repositioned to show the proper sequence of operations. This is a 50+ minute video so make some time to enjoy it.