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…........................... .--- Tunnels & Turnouts ---

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Finally finished tunnel portal designs with Fusion 360. Ended up with 23 different designs total and printed them all out so can use the ones I like the most. I'll try and get the print files up soon.

I'd used the joint compound shown above recently laying cork so it was still fresh in my mind. It is smooth and creamy and wondered how it would do filling the joints on the face of the tunnel portals that were block vs. flat concrete.

Found out that it works very well. I'd use Tamiya Putty on another and like the product but like the joint compound actually better. It is easier to spread with your fingertip into the joints and easy to wipe off the faces with a paper towel. I took the fine wire brush shown above to the joints also but probably won't use that step in the future as the N scale detail is too small to see that you used it.

I started the painting process right away with a black wash that seemed to soak in a bit into the joint compound. Then continued with other colors all brushed on. I happy with the results.

A while back I'd started making #6 turnouts for the staging area and needed to finish them and make more. I had bought a lot of ME code 55 flex track and have a Fast Tracks fixture to make #6's but when ME track got scarce I bought a fairly large amount of Code 70 flex as it was still available. I plan on using it in the hidden staging and other places where it won't be seen such as the track elevator. This resulted in needing code 70 turnouts for some of those areas so I built some and will build more with paper templates.

Since the turnouts won't be seen I could forgo adding wooden ties to them but I still need ties on the end and near the throwbar and a few in the middle to elevated the turnout to about the same height as the code 70 flex track. This is necessary since the PCB ties aren't as thick/high as the ties on the flex track. Also one wants the throwbar to be above the track surface so that it isn't dragging on it much.

I'd designed and printed the tie fixtures shown above so though I would use them to add the ties and put almost all the ties on this one turnout just for practice and to try them out more. They work really well if you are dealing with individual ties. I did make a change also on attaching the ties to the rail. I'd use Pliobond before and I really find it hard to work with. Even with the thin tubed tip applicator it seems to string and get into spots where it makes a mess. I switched and tried a medium viscosity CA glue with one of the really small applicator tips. It worked well. You still need to not apply more than a drop per tie so that it doesn't run down into the fixture.

I'd load the fixture with the ties for one section at a time. Then place the turnout on the fixture, supporting the ends with other fixtures. Put a drop per tie on the outer stock rails only. Then I used a long thin food pick that I dip into CA accelerator/activator and run it along the rail and it flows down into the CA and sets it. I pry the ties out of the fixture one end at a time with a X-Acto knife. If a tie comes loose on one end just re-glue it.

Using the fixtures makes this process go really quickly compared to how I've done it before taping ties to a paper template with double sided tape. I made the templates match the tie spacing on Fast Tracks templates.

More info on the tie fixtures and links to the print files ( HERE ). There is also a fixture that works with a Fast Tracks #6 fixture and other fixtures for curved turnouts.

Use a X-Acto knife to cut the ends off the ties.

I have files up for 3D printable servo brackets ( HERE ). Along with the brackets you can print install tools that really help installing the servos. A common problem installing servos is getting the bracket in the right place under the layout. The tool above really simplifies that process. The tool shown has two sets of pilot hole guides depending on if one is using the longer or shorter bracket. It has direction indicators on the bottom and the top.

Put the turnout where you want it and mark where the throwbar hole for the piano wire is. I'm throwing these with a hole near the end of the throw bar and drilled a 1/4” hole in that location. If you have the hole centered between the rails drill the hole there.

Put the tool in the 1/4” hole that is centered on where your throwbar hole is for the piano wire. I was able to reach under from the side and put the tool up through the hole and hold it there with the single set screw in the 'holding block' so that it doesn't fall back down ( NOTE: if you can't do that lightly tape the tool up against the layout from below. Go to the top side and push down to release the tape and pull it back up and screw the set screw in).

With the set screw holding it up rotate it so that the pointer/direction indicator on the top is aligned with the track direction. This will align the pilot holes for the servo bracket in the correct orientation. If you think it is going to turn run the two top screws on the 'holding block' into the layout to keep it from turning.

Back under the layout drill the two pilot holes you are using for the bracket screws. This is all quicker than reading it here. With the pilot holes in exactly the right place go back up top and pull the tool out (If there were two of you you could stay under the layout for the next step).

Run two #4 screws into the bracket to the point they are slightly sticking out on the other side. Now go under the layout and using the screws and the pilot holes you can position the bracket into place quickly and run the screws in. The bracket will be in the right place the first time and you can easily do this alone as the piano wire will be centered in the hole.

Often with other methods it can take two people and you need to center the piano wire with the servo. One person goes below and the other tells them to move one way or the other. Using the simple 'center tool' all of that is eliminated as the pilot holes for the bracket are easily drill right where they need to be.

I built the cheap 'tester' (shown above) out of a spare 110v to 9v 'brick' power supply I had and a $2.00 buck converter to change the 9v to 5v. Connected it to the switch box that I modified with a continuous 'on' option and another switch to turn the tester on/off.

I'm using $2.00 servo testers that I've modified to be the servo controller. At this stage with the tester connected to the servo controller you can adjust how far the servo throws the throwbar so that it doesn't over-power it. Once done you disconnect the tester and attach the switch box you will be using.

You can print different tops for the switch box that represent the turnout it is throwing. To throw a turnout you flip the toggle switch on the switch box and push the red button for a second or two and the turnout will throw and also the appropriate route indicator LED will light and stay lit. If the turnout is throwing the wrong direction you can flip a very small slide switch on the side of the switch box and it will throw the other way. This also gives you the option to mount the servo bracket in either direction under the layout if there is something in the way and still throw it in the right direction.

You don't need to build the tester shown above as you can use the switch box that will finally be used but it does make adjusting the servo controller easier. You can also use it to setup the turnout, servo and switch box before finishing the final wiring that will run to these items. On the tester I added a second on/off (black) push button switch. Turn it on and then throw the toggle one way or the other while adjusting the controller pots without having to use the red push button. You don't need this but helps when adjusting the controller as you don't need to also hold the red button down and adjust the controller at the same time.

One could use the 'always on' that the 'tester's' black switch has but then the servo is always powered. This means the servo is always powered and the power demands for the power supply used for the servos results in the need for a larger power supply. Using the red on/off switch results in the servos only drawing power while they are being thrown. I feel this is better for the servos and I can use a smaller power supply. Some of the servo controllers out there do have the servos always powered.

I'm using the 3D printed switch boxes for most locations but you can mound the switches that you see on the box on a more conventional layout panel that has multiple switches on it. The wire from the power supply buss to the switch box is two single wires or a pair. The wiring from the switch box to the servo controller and from the servo controller is the cheap 3-wire servo wires that have male/female connectors on both ends and you can find in various lengths including longer extension lengths. There is limitations on how long these wires can be but I don't see that as being a problem with any of the layouts I've seen.

One can put the all the parts shown above (servo, bracket, controller, switch box with parts) together for about $10 a turnout. That is way less than anything I've seen out there.

Cons:

1. If you want to control your turnouts say with one of the DCC options you can use the servo and bracket but that is it. You could control some turnouts via DCC and some this way.

2. You will have to do the switch box and servo controller wiring yourself but it is simple. The controller consists of adding two wires to it and an added printed circuit board pot. The switch box involves more wires but is not complex wiring by any means. See the link below for detailed instructions.

Pro:

1. This is pretty much 'old school' so you don't need to know how to program an Arduino or any other type of controller that requires a more complicated approach. The controller has two knobs on it. Turn one one way to throw the throwbar how far in that direction you want it to go and use the other knob to set the throw of the throwbar the other direction. Pretty simple.

2. Very inexpensive at about $10 per turnout for everything you need to throw it. You don't have to have a 3D printer but it helps with making the brackets and the install tool. You could make brackets other ways and install the servo like most people are doing now. Possible but not as easy. If you are doing very many turnouts printing brackets vs. buying them might just pay for the printer and they you have it for other projects.

Much more detail on all of the above ( HERE ).

If you came into the build here you can find the main index for the build ( HERE ).

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