Union Project: Handlaid Turnouts & Servo Point Control

Welcome back to the Union Project. In this episode, we'll review my first time using Fastrax turnout building jigs and Arduino-controlled servos for turnout control. Let's get started. In the last video, I installed all of the roadbed and began laying track, but was sidetracked when I needed to consider occupancy detection for my hidden staging yard. I needed to change my construction plan and develop a detection and signal system Picking up where I left off, I returned to laying track. When I embarked on this project, I had a bucket list of features I wanted to be included, and one of the things I wanted to try was hand laying turnouts, so I invested in a Fastrax turnout fixture. Here is a quick breakdown of the tools and supplies you need to fashion turnouts. The Fastrax fixture, the frog and point rail shaping jig, and a stock rail jig. These three fixtures provide all the tooling you need to build a turnout successfully. Additional supplies include code 55 rail and PCB copper ties. The system offers two options for railroad ties, laser cut templates or traditional wooden ties. I elected to use the wooden ties. The turnout construction process is methodical and straightforward. Using the fixture to cut accurate lengths and bend angles, you first fashion the guardrails. You next build the first half of the frog, filing the ends of the rails in the frog shaping jig, and soldering the two points together in the turnout fixture. The frog and guardrails are set aside and you trim and insert the individual PCB ties. The ties are first gapped using a few swipes of a file. This is important to ensure that the opposing polarity in the rails is electrically isolated. Next, using the stock rail jig, you file each stock rail so that the rail head and base are flush. This allows the points to sit perfectly against the outside rails. The stock rails are pre-bent, inserted into the jig, and soldered in place against the PCB ties. Once the stock rails are soldered, the jig used to file the frog points is reversed, creating the perfect taper for the turnout points. The points are pre-bent before adding a small gap that allows the guardrail to be shaped into the second half of the frog. Points are soldered in place, the frog is added, and the ends are soldered to the throw bar. The final step is electrically isolating the frog by cutting gaps using a jeweler's saw. The first turnout I built took about an hour to construct and worked very well despite its somewhat sloppy appearance. Fast track turnouts are straightforward to build and perform really well. However, two additional steps need to be taken before you can use them. The first step is deciding to power the frog, and the second requirement is adding switch machines. I have only ever used manual turnouts in the past, and I wanted powered turnouts for this new layout. I wanted to continue experimenting with Arduino controllers and use inexpensive servo motors for the turnout control. Like all things Arduino, many great examples are available online, so I won't go into detail about programming the required servo control motors. Still, I will mention that an episode published by Jimmy at the DIY and Digital Railroad contributed to 99% of what I learned. I'm Jimmy from the DIY and Digital, stay safe, be kind, and happy railroading. The principal difference between my setup and almost all other setups I've seen is that rather than use a momentary switch to control the turnout, I used a triple pull double throw stomp switch. A triple pull switch is unique, but perfect for my application because I wanted one of the set of contacts to control the switch machine, a second set of contacts to control the indicator lights, and the third set of contacts to deliver power to the frog, if necessary. I say if necessary, as the wheelbases of my passenger equipment span beyond the unpowered frog, so I don't need to add power. That said, I have wired each of the frogs in the event that I ever run shorter equipment, or I have technical problems. I made one slight modification to the basic sketch provided by Jimmy, changing the button read value on the switch off to state from greater than to less than 500. This modification allows me to use a toggle switch for turnout control, rather than a momentary push button switch. All right, welcome back. This is a brief update, you'll have to excuse the mess, but experimenting is ugly. So, I am using servos to power the points on this layout, it's the first time for me doing that as well, and I'm using the Arduino controller to move them. So, what I need to be able to do on the hidden staging yard is not only change the points effectively, but I also need to know what state the points are in via an indicator light. So, I have combined a triple pull double throw stomp switch with a pair of LEDs hardwired through the Arduino controller and a servo motor, so that when you hit the switch, it shows the indicator lights changing, and the servo moves. The last thing the switch does is help route power to the frog, because hand laid turnouts aren't powered. Anyway, that's the update, talk to you soon. To simplify the installation process for each servo, I designed and 3D printed a simple bracket to mount the servo to the underside of the table, while providing a pivot point for the throw rod. The throw rod was bent from .6 millimeter piano wire, inserted into the actuator arm on the servo, and then passed through the pivot point. The servo was glued directly to the mounting bracket, and the mounting bracket was glued to the underside of the table using thick super glue. This allowed me to fine tune the placement of the servo before letting the glue set. Once the glue had thoroughly cured, two additional screws secured the servo in place. I fashioned a temporary mounting bracket for the switch and indicator LEDs. Stomp the button once, the turnout points change, and the LEDs indicate which direction the points are facing. Stomp the switch a second time, the points return, and the indicator light changes. I spent the next while carefully installing and testing the six switch machines in the hidden staging yard. I declared the project complete when I could reverse a passenger train at high speed through the points without disaster. It was really satisfying to finally run some trains, even if it was back and forth through a staging yard. I learned a few important details about both the turnouts and the servos. First, the turnout needs to be finely tuned with a file at the point ends and around the guardrails, otherwise passenger stock will pick the points. A few swipes of a file and each turnout is now operating flawlessly. Secondly, Arduino controllers can only manage six servos maximum, and you cannot reliably power the servos using the onboard 5 volt power supply. You need to use an auxiliary power source with greater amperage to drive the six motors. I added auxiliary power, and now everything is working perfectly. All told, these few details were simple to correct, and after a few weeks of work, I now have a hidden staging yard that operates flawlessly with reliable turnout control and occupancy indicators. Next time I'm going to need to tackle the control panels. I need to deal with the mess of wires that the power and the turnouts and the occupancy indicators have created. I'd love to start adding the second level, but I will regret it if I don't organize the electronics sooner than later. Thanks for watching. I'll see you next time.