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I thought to myself "there must be an easy way to add turnout indicators, but how? My track work was already laid and I soldered turnout joints in a way that prevented typical signaling methods found on the web.
I looked into various methods such as slide switches (as shown on this forum) but every option needed real estate or significant prep work I had not undertaken when installing trackwork. Worse still, some sections I needed to modify had ballast installed!
So off I went to numerous hobby shops, hardware stores and electronic shacks! I came back with a whole range of bits, bobs and wire gauges hoping to find a discreet and simple way to implement a position indicator for my Peco turnouts. Now I must state up front that using Peco turnouts simplifies my problem as I do not need to worry about keeping the turnout in any given position as each turnout has a small spring that does the job for you.
After many prototypes and tests, I developed what I think is the most simplest method. It requires 2 holes, piano wire and a micro switch. That is it!
The best part is that the solution is extremely cost effective and fully serviceable.
Here is what you will need
- 1.19mm (0.47") piano wire (I used K&S brand purchased from hobby shop)
- Micro switch (I choose switches with long handles that take less force to engage) (purchased from Jaycar)
- A 3.5mm or 4mm drill bit with a screw pilot stop device attached. (purchased in a 4 size pack from Bunnings)
- Needle nose pliers
- Small hand operated drill with a 1.2mm drill bit (to accommodates piano wire size)
- Tweezers (not necessary if you don't have one on hand, but helpful)
Attachment 54748
Peco turnout areas we will modify (actually drill through!)
Here is a picture of a medium Peco turnout. The location of the first hole will be in the turnout's back support piece which helps hold the existing spring in position. The back support piece has two square holes on each side (used to hold Peco switch motors). We will drill the first hole through one of these existing square holes. I prefer using the hole closest to the backdrop (away from layout edge) as it hides the control wire more easily from sight).
The second and third 'guide' holes will be drilled threw the existing round holes on the switch throw handle on the same side. This existing hole is perfectly sized for the piano wire we will be using (thus why I chose 1.19mm wire).
Attachment 54749
Step 1 - Drill the back support hole
First step is to use the small hand drill to make a hole threw the benchwork via the existing square hole on the back support piece of the turnout. Be gentle and go slowly. Don't push down on the plastic as you may bend or break it.
Once you reach through your benchwork, give the drill a few turns to loosen the hole a bit (not too much as we want the wire leg to hold tighly otherwise you will end up with a wobbly loose control wire!).
Attachment 54750
Step 2 - Drill the two switch position holes
Next we need to drill two holes through the existing hole found on the switch throw handle. The throw handle is made of a softer plastic and is more susceptible to bending if your are not gentle. Drill through it gentle and don't push down hard. Let the drill bit do the work. The holes we will drill in this step will be used as guide holes underneath the benchwork to position the larger hole we will drill later.
Throw your switch in one position (does not matter which way you choose!) and drill your first hole. Once done, throw your switch to the opposite position and repeat the drill process. Once done, you should have two guide holes to reference under the benchwork.
Attachment 54751 Attachment 54752
That's all the modifications we will make to the turnout. Technically we did not do anything to it except enlarge existing holes slightly!!!!
Step 3 - Create the throw handle hole
Now we need to prepare a larger hole under the benchwork. First you need to grab your power drill and insert your 3.5mm drill bit with stopper. This device is normally used to drill holes that allow a countersunk screw to sit flush in woodwork. I purchased mine from Bunnings (here in Australia). I bought a four pack for $18 consisting of drill bits ranging from 2.4mm to 3.5mm with each having its own sized stopper.
Take note of how I positioned my drill bit by placing it against my benchwork. I don't go above the benchwork line as the stopper does not fully engage at its tip and tends to go a tad bit deeper. The important thing here is to position the stopper to the right depth of your benchwork. When used, the stopper will prevent the drill going any deeper unless you forcibly push on the drill once the depth is met. Practice drilling a few hole in some scrap benchwork wood you have lying around until your comfortable that your turnout is in no danger of being mangled by a rogue drill bit!
Attachment 54744
Once you have prepared your drill bit and stopper, drill your hole slowly until the stopper engages. I normally drill exactly between the two guide holes I made and then press left and right on the drill to expand the width in each direction of the throw handle above it. Be careful not to drill into the back support hole nearby as this needs to remain separate to keep the wire we will install stable and not wobble when throwing the switch. In the photo below, you can see in the upper left corner an existing control wire installed and how the two holes are kept separate with the back support hole doing the stabilizing work.
Attachment 54745
Step 4 - Build your control wire
Next we take our piano wire and create a U shaped control wire as shown in the picture below. The length of the legs will be based on your benchwork depth. I left enough length on each leg so that the wire pokes threw (if you cut it too short you risk the wire not holding firmly in the back support hole). You will notice that I make one leg longer in order to identify the leg that will go threw the larger hole via the switch throw. This ensures that there is enough length on the wire to firmly engage the micro switch handle.
I found that roughly a 4mm gap is ideal to reach the back support hole and throw handle hole when I install the wire. This of course will depends on the needle nose pliers and your skill with bending piano wire which is quite strong! It took me a few tries to get the shape right, but after I while I figured out where exactly to position the piano wire on my pliers to get an almost perfectly spaces u shape with a 4mm gap between the legs.
Once you have constructed the shape, cut the control wire with the cutter device found on your pliers (this may require a bit of muscle power depending on the quality of your pliers and piano wire!).
Attachment 54753
Step 5 - Install and test control wire
Now we need to install the control wire into the two holes we drilled. Gently and slowly place the wire into the holes and push down. If the wire does not want to go down then give the legs a bit of a pinch with your pliers or tweezers as the legs may be catching on the wood going down. An important thing to keep an eye on is whether the wire is forcing the switch throw handle upwards/downwards. This is an indication that the gap is not correct between the wire's legs.
You have two options to resolve this:
- Adjust or build a new control wire
- If the malformation is happening in only one throw position then get your small hand drill bit and slightly enlarge the switch throw handle hole (not the back support hole)
Assuming the wire now fits and can be pushed easily down (and removed easily), your next step is to test the wire in each position by throwing the switch left and right. The objective here is to ensure that each position engages the rails completely as if the wire was not even there. If there is a slight gap in your rails then you need to remove the wire, get under the benchwork again and enlarge the large hole slightly in the direction that is not engaging the rails properly.
The end result is to have the wire engage the positions fully and not feel stiff or difficult when throwing the switch. A final observation, if done right, the control wire will also assist the turnout to hold its switch position more firmly which assists with electrical contact (this is not an issue with me as I have dropped feeders on all ends of my turnouts for DCC operations).
Attachment 54746
Step 6 - Install your micro switch
Now that you have your control wire installed, you can position and install your micro switch. I chose to use a micro switch that has a long handle that is fairly easy to move and engage (some have stiffer engagement mechanisms). I install my micro switches using 4G x 20mm hinge-long thread countersunk head screws (that's a mouth full!). The 4G is typically a 2.5mm screw which I can 'snugly' screw through the micro switch holes and prevent movement. I didn't have any micro screws so this is an acceptable option for me....but you can go crazy and buy some of those tiny micro screws if you want!
How and where you position your micro switch is up to you, but I found using a test buzzer helps to figure out the ideal position for the turnout to engage and release the micro switch in each position. You can find instruction here (scroll down to testing section) on how to construct the test buzzer which is a useful tool for any DCC user.
What you do with the switch is out of the scope of this tutorial. If you want to run it to a signal, control panel or some other form of indicator is your choice.
Attachment 54747
That's it, an easy to build, cheap and serviceable indicator method.
- You can install this control device before, during or after you have laid your track work or scenery.
- If you need to change the turnout, you just re-drill the plastic bits on the new turnout and reinstall the existing wire.
- If your control wire plays up (mis-shaped) then replace with a new one.
- If your micro switch dies or does not engage properly then replace or move it independent of the control wire installation.
- As the control wire rests in holes through the turnout, it is not susceptible to seasonal contraction or movement in track work.
- The control wire is non-intrusive and takes up zero real estate around the turnout.
- And the best part, the piano wire color blends in with the turnout if you don't want to paint it.
- Once you get the hang of it, you should be able to do a turnout in about 10 mins.
Hope this tutorial helps!
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