2017-04-22

Benchwork construction

One of the first things one must tackle when building a train layout is how to construct the benchwork. (Before the benchwork has been started, I find it best to paint the walls and ceiling blue (sky) and mount any backdrops.)

I make my benchwork from cheap lumber commonly sold at building and home improvement stores in the USA. They are called 2x4 studs (actually 1½" by 3½") and typically come in 8' lengths. Don'y buy too many at a time, they can warp and twist if you don't use them for too long.

I mount these studs to the walls at floor level as well as at the desired height (lowest track) of the layout surface. I then build a framework using joist hangers and drywall screws in a horizontal plane. Support is then provided by studs at 45° from the stud at the floor level.

This produces a very strong foundation without legs at the front edge - allowing excellent access and storage below.

For benchwork that does not run along a wall, such as an area that protrudes into the middle of the room, you cannot escape having some legs. For those I create adjustable legs from, studs.

Once the framework is in place and supported with the diagonal braces, drill a bunch of holes in the framework for threading wires. When you have done that, drill a whole bunch more, because you will need more than you think.

Thread the main bus wires. You will need the following bus wires:

  1. Common ground (Heavy guage, I use brown)
  2. Track power digital signal (Heavy guage. I use red)
  3. Accessory power (I like to use 12 Volts DC, Heavy guage, I use white)
  4. Multi-strand cable for track detection feedback wires.

In addition you will later be installing wires for signals and various accessories.

Bring track power close to where you expect the tracks to be. If you expect to have multiple power districts with boosters, decide now where those districts will be and provide separate track power to those areas. Don'f forget to run wires from your power supply to where you control area will be too.


If the upper surface is going to have a slope, you can use ¼" threaded rods to hold a sheet of plywood at the appropriate height. I drill a hole into the framework, then drive the threaded rod into the hole. To drive the rod, lock two nuts together at the top and drive it in using a drill with a socket that matches the size of the nuts. Once in, unlock the two nuts and move them down the rod to whatever height is needed. On top of that I thread a strip of wood or metal to provide support for the plywood roadbed.


Once the supports are in place, you can add the plywood that will support the track.

Adjust the heights, then hold the plywood down by adding a washer and another nut.

I suggest using ⅝" plywood.


In places where there you need to support multiple layers, rods can be added as needed.

For layers that are horizontal it is also easy to make supports by cutting short lengths of wood and screwing them to the sides of the frame. This allows the plywood to be securely fastened down from above.

If track is going to be hidden by upper layers of benchwork, lay and wire up the track (including train detection) that will be hidden before covering it. Test it thoroughly.


In order to prevent the wires from an upper level from fouling trains below, I partially screwed a series of 1/4" screws into the underside of the upper layer before installing the board. Then when I lay track above, I drill through and thread the wire through the hole and then lead it to the nearest screw, wrap it around twice and pass the end between itself and the board and then lead it down to below the lowest level where I tap into the bus lines...


Add LED lighting on the underside of layers that are above hidden tracks.

Plan on hanging curtains on the front edge of the layout so that one cannot see through the landscape.

Once you have the top benchwork in place, you can at last start laying visible track!


2017-04-21

Layout photography

This page is an attempt to provide some tips on taking decent photographs of your train layout. Some of the original text dates back to September 2006 and I have now updated it in places where the technology has changed.

Some people have asked how I produce such nice sharp images of my train layout so I thought I would describe the techniques that I use.

Camera selection

I used a digital camera, initially a Nikon Coolpix 5000 which produced 5 megapixel images. 5 MP is way more than what is needed for images for the web and I usually had to reduce the size and resolution before posting on my web pages. I then used a Canon PowerShot pocket camera for many years, and I now use my Android Nexus 6P phone!

Here is what is important.

  • Minimum focus distance. Thankfully, many digital cameras now have excellent minimum focus ranges such as 2 to 5cm
  • Ability to select aperture priority mode. The camera must be able to let you select the aperture. This is important for controlling depth of field.
  • A self timer. This lets you set a delay before the camera takes the picture.
  • A fold out viewfinder is nice to have.
  • Ability to switch the flash unit off.
  • The smaller the camera the better, as it is easier to place a small camera on the layout itself.
Sadly, my phone camera does not allow aperture control. It does however have automatic HDR (High Dynamic range) which produces wonderful high resolution images. I typically have the camera in my pocket so it is very hand to pull out and use, especially when documenting progress, etc.

Lighting


  • Switch the flash unit of the camera OFF. The flash is usually way too intense for close up work and the camera does not have enough time to react and end the exposure before everything in the foreground is burnt out (over exposed)
  • Try to get as much constant lighting onto the subject as possible, but having said that, the lighting should resemble the real world as much as possible, so do not create the illusion of 4 suns in the sky by having 4 lamps at different positions, producing 4 shadows for every object!
  • Do not put hot lamps near the models as it may simply melt the precious models. These days very bight LED lights are readily available and very practical. You do not need a huge amount of light anyway as you will see.
I have a very bright LED light on its own tripod. I have taken some pictures with it as the sole light source which produces realistic shasows.


Depth of field

If using a phone camera, you may not have aperture control so you can skip this section.

Depth of field is the area that is in focus. The smaller the aperture the more depth of field you will get. Small apertures have the larger numbers, such as F8, f11, f22. The closer the subject is to the lens, the smaller the depth of field. Since we are photographing tiny models, we generally have to be very close to the subject and that is why it is critical to compensate by using as small an aperture as possible.

Small apertures however reduce the light getting through the lens, so in order to get enough light we need as much light as possible or we increase the duration of the exposure, or both.  Once you have maximized the amount of light using reasonable means, such as room lighting or positioning an additional light in place, the rest is done by long exposures.

Positioning the camera

Since we need fairly long time exposures, we have to ensure that the camera is still during the exposure. This rules out hand holding. You could use a tripod, but that limits you to scenes near the edge of the layout. You can also get very small tripods that can be placed on the layout as well but this is not very practical.  What is practical is a very small beanbag and or a couple of small wedges that can be placed under the camera in order to direct the lens in whatever direction you need. This is where a viewfinder that can swivel comes in handy.

Positioning the camera right inside or on the layout produces a point of view that closely matches what a person on the landscape would see. The closer you can get the center of the lens to the ground the better. This is how we see a loco:

Try to include some human interest... like these hikers watching the train...

Taking the picture

Place the camera on the layout. You may be limited to space on the tracks (take care the camera does not short out the tracks if the layout has to be powered up) or on a road or in a field.

  1. Set the camera to its macro mode if it has one, and its minimum focus.
  2. Set it to the minimum aperture (select aperture priority often marked 'A' and the highest f number  f8, f11, f22)
  3. Set the camera to use the self timer
  4. Position the camera using the wedges or beanbag to frame the picture. Watch out for distracting things in the background such as windows, wall lights etc. Ensure the camera itself is not shading the subject
  5. Press the shutter release and then step away so that you are not shading the subject area

By using the self timer, you reduce the vibration and movement of the camera that results from your finger pressing the shutter release. It is even better than a mechanical remote shutter release. Some high end cameras have an infra red remote release which would also work well.

The exposure may take 20 or 30 seconds. It needs all that time to get enough light in through the small aperture.

Movement

The long exposure times make it very easy to simulate train movement. Once the exposure has started, simply move the train either by hand or with a locomotive. It does not have to move very fast or far...

Some examples


First, not what to do...  taking a picture from a bird's eye view does not produce a view with which most of us are familiar..

This looks unsettling for those of us who do not spend much time up in the air. Even a pilot may feel a little uneasy going down at this angle towards mountains. This type of shot is only good for documenting the progress or how to build the layout. By taking the camera down to the track level you get a much more natural image:


Choose interesting perspectives:


If you have a backdrop image, use it.

Don't be afraid to make even longer exposures for night scenes.

Remember to switch loco lights on etc.

An example of movement

2017-04-19

Positioning of the computer and control area

Over the years I have often seen a layout design discussed and thrashed out for an extended period, without any thought as to where the control area will be. Things like control areas and computer screen take up space and really need to be considered when designing the layout.

Whether you are using a simple digital controller (or a few), analog controllers, or a computer, the devices have to live somewhere. Walk-around hand held throttles are now commonplace, but serious layouts still need some sort of overall display of the tracks and where trains are. Station control desks (Stellpult in German) also need space and you don't want them sticking into the already small walkway.

It is good to have this area somewhat central to the layout room, or at least as close to the main action as possible. Being central, typically allows best and fastest access to the control desk. If you have parts of the layout that require 20 seconds to walk around to, you may need to have satellite controls, or hand held controllers too.

The location of the digital central controller also dictates how the wiring will be routed to items such as feedback modules, boosters, and power districts. A computer is often close to the central digital controller which is also often close to the feedback systems.

If using a computer, the biggest issue is the placement of the screen. The computer itself is easily stowed away under the layout and the keyboard and mouse are easily accommodated on a small drawer, but you don't want to have the screen obscuring the layout.

The screen issue can be solved in these ways:
  1. Place a small screen at an angle, lower than the front edge of the layout. This demands some space off the edge of the layout.
  2. Place the screen on the wall behind the layout. Needs to be somewhat larger, needs longer cables or wireless connection, but can look ugly hanging in the sky above the layout.
  3. Place the screen in a recess in the side of a mountain. This tends to be towards the edges of the layout, because that is where mountains typically end up.
The main thing is to consider it, when designing the benchwork and floor space.

I suggest making the control desk space generic. By this I mean you should be able to swap out the computer for another one. Try not to make a carpentry project out of mounting the monitor, as you may have to redo it when you have to replace the monitor. You might also use a laptop, so you need a shelf wide enough for the laptop and low enough for the screen to stay out of the way. The laptop itself can also be stowed away like a desktop CPU and have an external keyboard, monitor and mouse attached.

Here are some pictures of my control desk from my first layout.


The computer itself is on the floor below the layout and it is connected to the LAN, Intellibox, a small flat screen monitor, keyboard and mouse. The monitor sits at an angle so that is does not obscure any of the layout. On the same shelf is the Intellibox and mouse.

Below the shelf is a keyboard drawer. The keyboard is not needed much when running trains so it slides underneath out of the way.

The location is central in the room.. and there is sufficient leg room so that one can sit at the computer. I like to have the monitor, keyboard and mouse all black, on black shelving to stay as unobtrusive as possible.

On my current layout, I have upgraded the small monitor for one that has a higher screen resolution. It is a bit larger but the top edge still does not obscure the foreground of the layout. One can see part of the array of s88 modules below the monitor and the larger monitor.

Here is an earlier attempt at positioning the computer and monitor (before the age of cheap flat screens!). The idea was that the cart could be wheeled out into the part of the room that was not designated 'layout space' when the layout was in use. I abandoned this when I found that the power supply was causing magnetic interference with the CRT monitor, and I was also worried about how all the cabling would handle the bending that came with the movement of the cart.


The shelf at the front was hinged

Here is another early tryout using a laptop. This laptop wasted too much space in the front, so I switched to an old desktop PC to run the layout.



2017-04-12

LED lighting circuits

The topic of LED lighting is a popular one, perhaps because there are always so many answers!

The big question is always how much resistance is needed to protect the LEDs, but this usually leads to other questions: "How bright do you want the LEDs to be and how much voltage will be used to power them?"

First, a bit of technical stuff...

White LEDs
Usually we are talking about white LEDs, so the tables below assume white LEDs (warm or cool white). Such LEDs have what is called a  forward voltage of 2.8 to 3 Volts. That means they will light up when they get between 2.8 and 3 Volts. Giving them more than 3V will shorten their life considerably. (Minutes or seconds!)

Most LEDs can take 20mA (milliamps) or even 30mA of current but I suggest running them at around 15 mA for a number of reasons:
  • 20mA can tend to be too bright
  • 20ma is too close to their maximum rating, meaning small variations in the power supply or other components may cause them to blow
LEDs can only use DC power and their polarity matters. Because of this I often install a diode in the circuit bringing power into a building using LEDs. This is simply to ensure that if I connect the wires to the building incorrectly, I won't destroy all the lights in an instant. The additional diode consumes between 0.5 V and 0.7 Volts

The next factor to consider is how many LEDs are to be powered on a single string. This is limited by voltage of the power supply. Each LED will use up its forward voltage (2.8V to 3 V), so a 12V supply could drive 4 LEDs per sub circuit.

Each little string of multiple LEDs (with their own resistor) will draw the same amount of current as a string with just 1 LED in it.  i.e. a circuit with 4 LEDs running at 15mA would also use 15mA with 4 LEDs (and would use a smaller resister).

The number of sub circuits you can connect to a single power supply is determined by the sum of all the mA used by all the sub circuits. So if your power supply can supply 1 Amp (1000 mA) of power, and you circuits draw 15mA each then you can power 66 such circuits (1000 / 15). If your power supply is rated in Watts, simply divide the Wattage by the Voltage to get the Amperage it can provide.  For example, a 24 W power supply at 12 Volts can provide 2 Amps.

Resistor values
Though resistors are available in almost all resistor values (Ohms), there are common sizes that are much more available and cheaper. So, after calculating a resistance, you should pick the next higher common resistor size.

Power supply
I recommend using a 12 Volt DC power supply for accessory lighting. PC power supplies are cheap and provide lots of Amperage, allowing you to power lots of lights. For convenience I have highlighted the 12 Volt column in the table below.

So here is a table of resistor values for between 1 and 7 LEDs connected in series using various voltages.


Here is how to use the tables:
  1. If you are not including a diode, use the upper table. If you are, use the lower table.
  2. Determine the voltage of your DC power supply. That determines what column you will use.
  3. Look at the row that matches the number of LEDs you want to string together into a circuit.
For example, a circuit with 3 LEDs, powered by 12 Volts, with a diode suggests a 200 Ohm resistor is needed. (This will run all 3 LEDs at 15mA.)

The next biggest common resistor size is 220Ω
(See http://www.logwell.com/tech/components/resistor_values.html for resistor size tables or search for "Decade resistor values")

The circuit will look like this (Components can be in any order)

AC supply

If your power supply is AC and you don't want to see flicker in the LEDs, then you need to rectify the power. Here is a sample circuit you can use. (You can use between 1 and 7 LEDs using the first table and the 22V column)
It uses:
4x  1N4001 diodes
2x 3mm white LEDs
1x 1100 Ohm resistor (2 LEDs)
and when soldered up it looks like this:

Note that when you rectify AC power, the resultant DC voltage is 1.4 times that of the AC voltage. So rectified 16 V AC will give you about 22 Volts DC

Note

If the components in your circuit are not high quality, their electrical characteristics may change after being powered up for a few minutes. If you suspect that your components are a bit flaky, here is how to determine what resistor to use:

  1. Select the resistor using the tables above.
  2. Using an ammeter, measure the current in the circuit. Let it sit a good 3 or 4 minutes. If the mA reading starts climbing above the desired amperage (15mA) remove the power and increase the size of the resistor, and try again. (To measure the current your ammeter must be in series with the circuit.) If the stable current reading is too low ( < 15mA) then decrease the size of the resistor and try again.
A variable voltage power supply comes in very handy when reducing resistor size, as one can start with a low voltage and bring it up to voltage while watching the mA reading, thus preventing LED damage by using a resistor that is too small.



LED related posts

2017-04-05

Disaster - take care when drilling!

I was adding some trees to the almost finished landscaping, drilling a hole for the tree, when all of a sudden disaster struck!


What happened?

Well it caught me by surprise, but in hindsight it made sense. When making the mountain, I used a layer of cotton sheeting underneath the plaster. When I drilled through the plaster to plant the tree, the sharp drill bit caught the cotton cloth. The cloth then wrapped around the drill bit, pulling it towards the drill. This caused the thin layer of plaster to burst out and it sent bits of landscape flying. The drill also moved sideways as the cloth took a firm grip on the bit.

Here is what the hill looked like minutes before:


I had friends coming to visit the layout in 2 days so I needed to repair things right away.

I tucked the cloth back in.

Added plaster


When it was dry, I did some chipping at the surface, painted it black and then brown:

Added some grass back and tried to blend it as best I could with the original surface. I then planted the trees, but without drilling into cloth, now I make the holes with a bradawl.


This time I added a rough path down the slope.

2017-03-27

Adding concrete and cable style road barrier

When I made the road past the farm in 2007 I used a set of steel fence with concrete posts made by Faller (item 180432). Now that I have painted the road along the side of my big valley, I decided to add some more of that kit there.



Here are the steps I used to install them.

I found that I had insufficient wire left over for both strands along the length of the road. Not finding anything small enough in my workshop, I went to a craft store where I found some nice thin (26 gauge) wire in the jewelry/beading section.

The first step was to drill holes and glue the concrete posts in. I always install a second post anywhere the fence starts or ends.

I then threaded the strands of wire through all the posts.


The wire does not easily stay straight, and the two strands together typically adopt shapes that do not match each other either.


I thus found that I needed to apply some tension to hold the wire in a uniform shape. This was rather easy to do, by drilling a hole just beyond the last post and pushing the wires all the way to underneath the layout. After pulling the wires taut, I simply wrapped them around a screw to hold them taut.


On the top side, I added some glue to the hole and added some grass on top of that.

It produces a believable scene!

2017-03-14

Telephone poles

I have had some HO scale plastic telephone poles in my train stuff for 3 or 4 decades and I decided it was time to install them. I have no idea where they came from or what brand they are. They were plain brown plastic, and one was a very different brown so obviously came into my possession at different times.

After checking that such poles are indeed still seen in Germany and that the insulators are also white, I painted the insulators a gray color. (I decided that pure white would be a little too bright.) I also painted the poles with some black paint to remove the glossy nature of the plastic.

I had 9 poles that were usable.

The biggest task was deciding exactly where they would go. One often sees them running alongside a railway line (or road) but most of my longer runs eventually run into a tunnel, so I decided to place them along the road that also runs next to my mainline for a short distance. One end of the road runs to the edge of the layout and the other ends in the town near the illuminated buildings. The 9 poles could be spaced nicely along this route so that decided their location.


To mount each pole, I drilled a short hole, vacuumed the waste, and then inserted the pole that had been dipped in some glue.


No wires will be added, they are too thin to be seen. (And would be absurdly impractical to rig and maintain.)

See Road markings for information on the white road lines.