Originally, I decided to use the Fast Tracks BullFrog manual turnout control to switch my turnouts on the street level. (Note that ehe elevated track is a different story and will use remote control). I felt that this would be appropriate for street running trains in the transition era. My first three modules I equipped with those BullFrog control units and connected them with the Fast Tracks control rod kits to the fascia. Even though most of the street level turnouts are at the front of the layout close to the fascia, I was confident I could get them to work. I liked Fast Tracks’ BullFrog product. It is well made, solid and robust and it included a SPDT microswitch for changing the frog polarity.
Challenges with BullFrog Turnout Control
The proximity to the fascia was challenging from the start, however. I arranged the control units and push button at least three inches apart and connected them through a loop – see center photo below. Unfortunately, the resistance of the rod was still too high and throwing a turnout was all but effortless.
Furthermore, the high resistance of the rod connection made it harder for using appropriate force to throw the switches. This led to several broken throwbars after a while. This is usually not a big issue and can be easily fixed with the soldering iron. Repairing a switch embedded in cobblestone is more cumbersome, however. In each case I’d have to remove at least part of the (lightly glued) cobblestone cover sheet. I then could solder the broken points to the throwbar – see the rightmost photo above. To finish the work, I’d have to glue down the cobblestone parts again. Doing this once would work but I was worried of this becoming a recurring task for the entire layout. Based on this experience, and also realizing that I couldn’t use manual turnout control for the W26th Street Station, I decided to switch to electric control of the street level turnouts.
Servo-based Turnout Control
I’ll use SG90 RC servos mounted in brackets as I’ve done this before for my Bronx Terminal layout. For the brackets I’ll use some leftover Tam Valley Depot SwitchRight brackets and their new B3D001 successor product. I’ll also use Digitrax’ new DSXSV9 9G Turnout control servo with mount bracket product. The DSXSV9 has a smaller footprint than the B3D001 since the servo actuator rotates around a horizontal rather than vertical axis. I’ll use the slightly more expensive Digitrax product where two turnouts are close together such as in a crossover configuration.
Using SG90 servos and brackets without an embedded accessory decoder leaves my with the choice for a low cost DCC integration. I was briefly considering Layout Command Control (LCC) as the bus for controlling turnouts and other accessories. The products from RR-Cirkits scale well and implement the NMRA LCC standard. Surprisingly, they have a very low unit cost per turnout and don’t look overly complicated to use. Also, I wasn’t worried about a steep learning curve as meanwhile enough training material is available. Weighting pros and cons, I rejected the idea, however. Using LCC for a 7 by 7 foot N scale layout appeared to me a bit over the top. At least for now.
For now, I will switch from local to remote turnout control using my ESU Command Station. I’ll definitely provide additional local turnout control through buttons or little control panels on the fascia once my modules are properly integrated in the layout benchwork.
Bus Design
Instead, I’ll stick to a separate DCC bus for accessories. I’ve been using both ESU’s SwitchPilot and Team Digital’s servo controllers. For my past designs, Team Digital’s SC82 accessory controller for 8 servos had the lowest per-unit cost. Meanwhile, ESU’s new SwichPilot Servo Version 3 for 8 servos has a comparable per-unit cost. In addition, Team Digital has discontinued most of their products so I’ll use the ESU SwitchPilot products.
The electrical design for my layout will include three different busses. The DCC Track bus (red) is the primary DCC control bus that provides the power to the tracks and controls motive power. A Tam Valley Depot DCC booster with its own 12 Volt-5 Amp power supply provides a separate DCC Accessory bus (blue) using the DCC signal from the track bus. An independent DC source (yellow) from a separate 12 Volt power supply provides a stable 3 or 12V source for lighting on every module. The board is the PCB012 product from Evemodel. In some situations I might use an Arduino based DCC accessory decoder for controlled lighting powered by the DCC accessory bus.
Module Independence
My modules are all self-contained and should be independently operable of other modules as long as the three busses are powered. An exception to this rule is the DCC booster that serves the entire layout and exists only in one instance. Additional per-module devices will typically be frog juicers and accessory decoders. The photo above shows the undertable installations for the B&O W26th Street Station and its freight yard. This includes a Tam Valley Hex Frog Juicer/Auto Reverser for the 10th Avenue Wye connection, the frogs of the crossing and some turnout frogs. It also shows the ESU SwitchPilot for all turnout servos of that module. Other elements are terminal blocks for DCC track feeders and for 12V DC power consumers.