Lima 42 Remotor + DCC

The old Lima 42 class diesel has been around my layouts for decades and I am not too proud to run it mixed in with all my more recent and highly detailed models. It ran well on DC and even better on DCC with a LokSound V4.0 decoder coupled with a replacement pancake motor and pickup on all wheels.

The motor shown in the top 2 photos was purchased on eBay as a specific replacement for the 42 class and other similar models. It satisfies the requirement of isolating the motor from the frame for DCC and runs well.

I always try to achieve pickup on all wheels or as many as possible. In this case it was easy. I added two small pieces of PCB to form solder pads. They are clearly visible attached to the two sideframe brackets with epoxy and carrying the RED flexible feed wire and the phosphor bronze pickup wires.

Note the holes shown in the bottom of the chassis to the top left. These are for the speaker shown in later photos.

A thicker piece of copper wire connects the 2 pads and one carries the p/bronze wires for 2 wheels and the other for 1. The photos show the setup.

The photos above and below show the decoder attached to the roof of the body shell with Blu Tack and small piece of strip board (Veroboad) used to carry the series resistors (1k – 1000Ω) for the front and for the rear headlights. Notice the “interrupts” cut into the tracks under the resistor. These were made with the tip of  a small drill. This isolates both ends of the strip. Normally the resistors would be mounted on the other side of the board but this method works  just as well

In the photo above I have removed most of the interior glazing except the sections for the front and rear windows. The portholes are glazed with Butyrate 15 thou strips held in place with tiny spots of Canopy Glue. [K & S Clear Plastic Sheet #1308]

In this model I used a 5mm (front) and 3mm (rear) yellow glow LEDs with ends of the LED filed flat and then polished. To avoid light appearing from other than the headlights, I carefully painted all but the front of the LED flat black.

I couldn’t find an appropriate and cheap socket to accept the 8pin decoder plug on the LokSound V4 so I made my own from a machined pin DIL (Dual In Line) IC (Integrated Circuit) 8 pin socket (eg Jaycar part# PI-6452 or on eBay).

The first step is to carefully cut the socket into 2 parts…

… as shown here.

Clean up the cut edges – the ones below need to be filed, but it’s not important as the correct spacing is achieved by gluing the IC socket back together on the smooth faces…

… as shown below with the prepared pair stuck in a blob of Blu Tack. Rough the surfaces a little and bond together with a spot of epoxy.

For this installation it suited me to bond the lead weight into the chassis with silastic and epoxy the prepared socket to the top of that. I have an old plug cut from another hard wired LokSound decoder that I can use as a guide to indicate which coloured wires need to be soldered to the rear of the new socket.
Note that installing the socket this way means that the off-centre plug can only go in one way around (good).

The mounting position of the speaker is shown above requiring some holes to be drilled in the bottom of the chassis. The speaker (which is not my preferred sugar cube type but was one of a number of spares I had in the workshop) is mounted just clear of the surface to allow sound to escape into the body shell. The speaker fits within the its housing but importantly, needs to be very carefully sealed into the housing. I use Canopy Glue on a toothpick to carefully seal every gap around the edge of the speaker, keeping it clear of the speaker cone. Also seal the spaces where the wires exit the housing – silastic may be better here.

This was the 25mm (1″) 4Ω  1.5Watt speaker and enclosure used for this project.

Here is a short video:

“Charles” Gets a Decoder

A project with a difference – PART 2.
A friend has a Fleischmann™ type 4028 0-6-0 Steam Locomotive which he would like to use as a “proving” loco for his under-construction Wolgan Valley layout. It’s a sort of a recycling exercise. This is the next exciting episode – Charles gets a decoder!

The decoder is a LokSound V4.0 running the ESU sound file: 54413-LSV4.0-Dampf-BR80-R5      It sounds like this:

Very Germanic!! But it will be OK for the purpose, assuming that the NSWGR may not have bothered changing the whistle.

This is where the LokSound decoder will reside. For a tank engine, the Fleischmann 0-6-0 has plenty of room. After a little testing, it was least obtrusive in the cab roof and is held in place with Blu Tack.

There are other things to do with DCC sound installs one of which is the Speaker and more details will follow. This is one is my favourite Sugar Cube speakers in my favourite mounting area – the smokebox. That way the sound comes from the right part of the loco! [post coming on fitting a sugar cube into the smokebox of a brass 30T class loco]

The motor, especially in this ringfield type requires special attention to make sure that it is isolated from the frame.
There is excellent technical advice on this in an article I obtained on the “All Aboard” Mittagong website – except it doesn’t seem to be there any more. The original PDF file I downloaded from “All Aboard” is however available HERE.

The replacement Isolated Motor Shield is shown below fitted to the mechanism. It is sold as Fleischmann replacement part # 50 4730 and is available from All Aboard as a spare part (not shown on the web site).

Here you can see the wiring from the decoder to the motor – Orange and Grey to the motor and Red and Black to the track pickups (loco frame and wheels). Some other wiring is visible and is described below.

The decoder has a number of unused function wires and they are held captive by the (yellow) kapton tape. Two extra simple PCBs are also visible. Simple PCBs are described in THIS POST.
The one on the LEFT has 4 strips – 2 carry the brown wires to the speaker (in the smokebox) and 2 carry the wires to the front headlight.  The bottom strip can be seen to have a connection via a resistor to the WHITE function wire (headlight).

The value of the resistor is 3k3 (3,300Ω) indicated more clearly on the board to the RIGHT where the colour code is ORANGE, ORANGE, BLACK, BROWN, BROWN which is 3 3 0 (1 nought) and (1 percent tolerance) ie 3300 Ohms ± 1%  This value is higher than most people use but it provides a more prototypical yellow glow in the Warm White LED.

Image© courtesy eBay

Incidentally the LED is a tiny pre-wired device where the LED size is 1mm x 0.5mm and is available in Warm White, Bright White, Red and Green & available on eBay for ridiculous prices.

Sold as: Pre-soldered micro Litz wired leads Warm White SMD LED 0402

They will fit into the smallest headlights on a loco but must be handled with care.

The pcb to the RIGHT is shown in detail below and feeds the rear headlight and the 3k3 resistor is on one strip which has been interrupted under the resistor making 2 isolated pads.

The common wire is BLUE and feeds to both small PCBs. The YELLOW wire is the function output to the rear headlight.

The speaker used is a Sugar Cube which measures 12mm x 14mm x 5.4mm thick (bare). This is one being prepared in an enclosure.The following speaker is ready to go in:More about speakers in a separate Post.
And to save you scrolling back up – the photo below is repeated and shows the sugar cube sitting in the Smokebox and under the chimney which has been drilled out so that the sound is coming from the front of the loco both top and bottom. I will go to any length to try to get the speaker OUT of the tender and into a more realistic place. You can detect the difference in a passing HO loco.

If the speaker enclosure is mounted on the chassis it is inconvenient to wire as a plug and socket arrangement would be needed. Instead, I have located the enclosure to the inside of the body shell by the simple of expedient of a blob of Blu Tack in the top of the body which “grabs” the speaker when you assemble the two parts.  [Yes, I know … there should be a plug connecting the decoder and the motor/pickups but I got lazy]

Here is another loco with homemade plugs and sockets so that the body mounted  speaker can be separated from the chassis:The 2 brown speaker wires from the decoder are connected to the speaker via a 2 pin plug. The body and chassis can then be separated. This loco is a 73 class shunter.

The next episode will cover painting into NSWGR “colours” but in the meantime, here is a preview of “Charles” making some noise! Deutschland Über alles!

“Charles” Gets a Makeover!

This is a project with a difference. A friend has a Fleischmann™ type 4028 0-6-0 Steam Locomotive which he would like to use as a “proving” loco for his under-construction layout. Sort of a recycling exercise.

He decided that a hypothetical, but possible scenario had occurred with his Wolgan Valley railway: “the NSWGR had decided to import a German 0-6-0 class loco for evaluation. Part of the process involved a repaint into NSWGR colours (or lack thereof) and a later sale to the Commonwealth Oil Corporation, Newnes for use on the Wolgan Valley line.”

Here is “Carl” pretty much as he arrived at Brolgan Road, with the exception of the Kadee couplers which have been fitted as described below.

My task was to implement that conversion on the model and convert it to DCC with sound. This is the story of that conversion of “Carl” (which name appeared on the side tanks) to “Charles” on its rebirth on the Wolgan valley line. I believe it will carry a NSW “X” number.

It is a little over the NSWR loading gauge but squeaks past my platforms. Wheel flanges are a bit gross but have been filed a little and now run through my code 75 points OK. As it is also to be a test bed for DCC it is an interesting exercise. The model itself is beautifully constructed.

Step 1 is the fitting of Kadees to match the rest of the rolling stock.
And in the process give it a good run on DC to make sure that the project is feasible. As you can see in the lead photo, it is running just fine on my layout under DC and it proved to be quite powerful and relatively smooth.

I am impressed by the engineering in this model but not surprised due to its West German origin. The chopper coupler keeper is easily removed by unscrewing the buffers.
That releases the keeper plate, chopper coupler and the centreing spring strip (latter 2 not used).
Tap the metal chassis with an 8BA thread (or to your choice) to suit a standard Kadee plastic machine screw.
As pointed out earlier, I found the existing hole in the front of the loco to be a little large and tapped the hole throught the plastic foot plate under the smokebox door. That means that the front coupler now needs to be unscrewed to remove the body.
The hole in the keeper plate needs to be enlarged to take the Kadee screw – I achieved that with a small file.
The screws are quite long and need to be cut to length (sprue cutter or similar) and the end filed smooth.
The chosen Kadee was a #149 Long Overset Whisker coupler to get the coupler jaws down to an acceptable height. The draft gear box fits within the existing housing and the mounting hole can be aligned with the original holes by trimming the back off the draft gear box.
The #149 coupler needs to be trimmed to length as shown below. You can see here why they are called “whisker” couplers.

The bottom plate is glued in place (I used Faller Expert Plastic Cement which has a nice fine delivery tube).
You can see here how the top lip has been cut and filed flush
The coupler height is still a fraction high – if it is a worry a small styrene shim could be added above the Kadee.
And here is “Carl Charles” happily coupled to a small freight consist. Still running DC.

The next post will cover conversion to DCC using a Loksound V4 decoder with sugar cube speaker in the firebox. Then the re-paint and a video of him chuffing happily away to his new home in the Blue Mountains.


The basics of DCC at “Brolgan Road”.

The backbone is a commonly used NCE system comprising a 5 Amp power supply to the left and the Power Pro DCC Command Station to the right.
The primary controllers are both wireless and consist of a Procab on the left and Cab-06 on the right.

The wireless antenna is mounted high on the wall and coverage is excellent in the small layout room.

Ground zero is near the main station Brolgan Road. A laptop slides out from beneath the layout when required. Left to right on the fascia: Brolgan Road Panel; the only NCE cab bus outlet (no others required with radio); a switch to isolate Brolgan Road DCC sub bus and the Procab. The shelf underneath houses L to R: a 12V power supply for the Canbus/ servos/ ancillaries; a grey box controlling power to the layout via DCC or DC (rarely used – just for testing); two track sections used as “Programming Tracks” – one for JMRI and the other for the Lok-programmer (shown below).

JMRI DecoderPro provides another throttle but more importantly, a means of programming the decoders in locos in a simple way and while operating on the main (line).

JMRI  stands for “Java Model Railroad Interface” – it is an open source program for model railway (railroad) hobbyists. It includes DecoderPro, Panel Pro and a Throttle. The computer above runs on the house WiFi and in my case I have a WiFi extender in the layout room as the signal from the router (modem) in the house is patchy.

Other throttles which can be used include:

  • smart phones,
  • tablets
  • iDevices

… using either “Engine Driver” app on Android or WiThrottle on Mac. Phones need to connect to the WiFi network in the layout room.

The DCC signal is fed to the rails and provides power to the loco; control of the loco(s) and other devices; and sound – if the decoder is so equipped. On the photo above the DCC main bus is “A”. There are some excellent websites explaining DCC operation and wiring and one of the best is by Marcus Amman at Main North.

The other Bus pairs shown above are:
B – 12 volts to power servos and other equipment.
C – DCC sub-Bus (because even though you can run ALL of your layout on the main DCC bus, it is bad practice when it comes to fault finding short circuits or other problems. Much better to isolate areas so that the fault can be found and operations can continue on the rest of the layout.
D – my CANBUS which is a control system which manages everything on my layout. See the post on MERG.

On the drawing board is a lot more material on DCC for future posts… Rick

Fitting Brass Numbers on Locos

I have fitted many brass numbers to HO steam locos, but it was so long ago I had to remind myself how to do it.

Frets of brass and nickel silver loco numbers are available at hobby stores like Casula Hobbies. The latter have sets like “AM-1 HO Numbers Brass Etch Sheet” & “AMO-4 HO Contractors Locos”

This is one way to do it – on a DJH white metal kit of loco 3214

The first problem is positioning the numbers on the cab side. With this 32 Class (3214), the rivets provide a good guide. Prototype photos also indicate the correct position for numbers. Always start with the middle number or the space between 2 middle numbers and work outwards. The number “1” requires a little more space either side.
Numbers need to be cut from the fret on a hard surface with a very sharp blade – scalpel in this case.
With care they can then be held in flat jaw pliers to remove any waste with a fine jewellers file.
I use a tiny dot of Blu Tack on the tip of a toothpick to hold and position the numbers.
In my opinion super glue is NOT the answer to attach the numbers.
Use a speck of dilute PVA or Canopy Glue applied with a toothpick to the back of the numbers. Canopy glue seems to dry a little faster than PVA but is also water soluble for cleaning up a disaster. It is great for attaching windows in models as it dries very clear.
Canopy Glue or PVA also allows a little degree of movement to shove the number around a bit.
Glue is on the back and I’m ready to position it by eye.
Small adjustments can be done with a scalpel or toothpick.
The end result showing the increased spacing either side of “1”.

I find it easier to apply brass numbers than decals.


  1. Another method I have used in the past is to use a strip of clear sticky tape after severely “de-sticking” it by repeatedly attaching it to a clean smooth surface then peeling it off. The tape needs to be super low stick so that you don’t peel off paint at the end of the process or that the numbers are pulled off when the tape is removed.The numbers can then be lightly attached to the reverse of the tape by the blue tack method or by picking them up with a super sharp scalpel point. The advantage is that the whole number set is done in one hit and the numbers can be adjusted and moved around before gluing. The disadvantage is that you are setting out the numbers back to front.Coat the back of the stuck-on numbers with dilute PVA or Canopy Glue and apply the strip with care. Once positioning is OK leave the PVA to dry for a day or so.
  2. It is also possible to lay all the numbers out on a clean surface using specs of blu tack , then pick the lot up in one go with the tape.

Manual Points by WIT

This section covers the construction and installation of mechanical lever frames which are not prototypical in appearance but do move in a manner not dissimilar to the prototype. Also covered is the associated “Wire in Tube” (WIT) operation and installation. The photo below shows some lever frames in position near the proposed Carriage Works in the early stages of my layout. Four of these control single points and two control facing points (crossovers).
In this post:-  “Point” = “Turnout”            “Sleeper” = “Tie”The lever frames are two assemblies – the frame mechanism itself and the housing.


The housing was fabricated from 2mm ply and a small block of wood.


The frame is based on a standard aluminium section plus some metric nuts, bolts and screws, an electrical connector, and a PVC and brass welding wire handle. I have some sketches – if there is any interest.
This frame is for a single point
This frame is for a crossover with one wire pushing and the other pulling. Component “A” is one of the brass terminals from a piece of Terminal Strip shown on the right. That makes it a very economical solution. The visible screw allows adjustment of the position of the point. The second screw in the same brass terminal piece allows it to be screwed to the handle with a small countersunk screw.
The aluminium mount is held to the fascia by a single screw through the bottom hole. The top hole receives the WIT.
This is the tube I used. It is the outer part of a Bowden cable used for the gear shift on a bicycle. A bike shop should be able to sell you a metre or two.
Test assembly – then glued with PVA
A single lever frame with the operating wire bent at right angles.
I use 1.25mm dia piano wire which needs a powerful hardened cutter as shown at the bottom of the photo above. In this install the WIT was fitted through a hole drilled straight to the nearby point.

For this crossover (above and below) near the front fascia of the layout, there was no room to fit a WIT the normal way. The frame directly controls the rearmost point by the bottom wire on the frame and this wire runs directly under the plywood mounting for the bellcrank (white above) and come up through the throwbar as can be seen below.
There is a very short piece of tube to hold the wire in place near the point. I glue these in with PVA.
In order to throw the second point in the crossover, the top wire from the frame operates a bellcrank which changes the direction of the pull (so that it is parallel with the fascia) and operates a second bellcrank for the front point.

To get some necessary adjustment between the 2 bellcranks, fit one of the brass electrical connectors (descibed in the picture 5th down from the top of this post). The interconnecting wire then needs to be 2 pieces – one long one and a shorter one near one of the bellcranks – as above.

The photo below shows the setup for the other point. I had to drill a hole right through the fascia to get the short piece of WIT to the throwbar. Again, the bellcrank is mounted to a thin plywood plate which will sit above the throwbar wire. You can buy these bellcranks from Model Aircraft shops.
The normal method of installing facing points with WIT is shown below. In this example originally there was only a single point and the trench for the WIT is still visible to the left. In changing it to facing points the frame was relocated; swapped to a double wire type; and new trenches laid for the WIT.

This jig is used to make sure the WIT hole(s) and the mounting screw pilot hole is in the correct position.
Here is an earlier version in use.
To cut the trenches, pin the tube in place over the best and smoothest path. Run a fine marking pen along each side of the tube.
Hand held Dremel and vacuum cleaner in use the cut between the lines.
This cutter does the job well. The vacuum is very necessary especially in the expanded foam unless you want to generate a snow storm!
This template locates the cut-out needed to accept the microswitch under the point.
The red lines are used to align it to the rails as the microswitch is installed off centre. That is explained in my post on MODIFYING PECO POINTS FOR DCC.

In some ways I preferred the manual point operation as it is more appropriate for my 1960s layout where the train crew or shunters did much of the groundwork. However the change to servo control does allow simpler use of area conrol panels and some likeness to a signal box diagram.

Rail Joins at Lifting Section

To make sure that joins in lifting sections are in alignment care needs to be taken.
The following method works well on Brolgan Road.

This is the latex carpet adhesive used to hold all the track, points and underlay in place. Preparing the join on the entry lift-up-flap a small section of cork was added to provide a stiff base. The PCB sleepers are soldered in place and the track suspended in the air with paddle pop sticks. The Tee pins allow the track to be aligned; then raised for the glue; and lowered into position.
The track has weights added until the latex cement sets. Note the plywood pieces to align the rail joins. Short pieces are great for keeping curves aligned where flex track joins.

Note: it would be better to use 5 sleepers instead of 3 to give a bigger bonding surface. Epoxy on these sleepers was a better option.

Three sleepers were removed and PCB replacements soldered in place. The middle of the sleepers sanded away to insulate both sides. The track is code 75.
When the glue sets, the join line was cut with a razor saw. Slow and tedious. The latex was not up to the job on these sleepers and I now use epoxy.


MERG (Model Electronic Railway Group) is an international, UK based group promoting interest in the application of electronics & computers to all aspects of railway modelling (quoted from their Website).

That covers one of my railway modelling interests and the annual fee of £20.00 (+£5 joining fee) is reasonable and includes a quarterly journal and access to a vast amount of information including a forum where your questions can be answered.

If you are doubtful about the quality of the group, you can download from the website a FREE book written by MERG member Davy Dick, entitled “Electronics for Model Railways”. This is a very comprehensive and informative introduction to the subject and I would highly recommend it as a worthwhile read.

MERG offer a growing list of kits, including Train-on-Track indicators, Gas Lamp Twinklers, a Computer Control system, DCC and the new CBus Layout Control System are available to members and, on occasion, ‘bargain’ components of model railway relevance. There are also basic projects & kits called Pocket Money Projects and these would appeal to starters in the hobby and those less confident in “things electronic”.

CBUS:  This is a universal layout control system developed by MERG members. The designers describe it as “a system for comprehensive layout control based on a general purpose Layout Control Bus (LCB). 
So what are the functions of a layout control system. You can divide these into two basic categories:

  1. Control of devices (outputs)
  2. Detection of ‘states’ (inputs)

Examples of (1) are changing turnouts (points), signals, power to block sections, turntables, level crossing gates, layout lighting, setting routes, controlling the speed and direction of locomotives (by DCC or analogue DC) and any other electrical or electro-mechanical devices that may be on a layout.

Examples of (2) are control panel switches, block occupancy detectors, bar code or RFID readers, turnout direction sensors, turntable position and ‘RailCom’™ track detectors.”

The choice of CAN: The CAN bus (Controller Area Network) was developed by the Robert Bosch company in the 1980s for use in motor vehicles but has since been applied to many other types of machinery including aircraft and medical scanners to name just two”.
Davy Dick, in “Electronics for Model Railways” describes it like this: “Imagine building a new layout consisting of four boards. With CBUS all you need do is run
four wires the length of the layout – two for power and two for the control system. No matter how many switches, button, lights, points, track occupancy detectors, accessories, etc. you now add to the layout, you still only need those four wires. The accessoryconnections between boards are always just these four wires – not the scores of wires associated with conventional wiring.”

But what does it look like on my layout, Brolgan Road?

In order to find out I built a small test panel to check things out as shown below. In simple terms the process runs from RIGHT to LEFT

  • starting with the module called CANUSB4. It connects to a computer off to the right by means of a USB cable and to the CANBUS twisted pair (red/white)
  • then comes the board labelled CANACE3 (to the designers, these acronyms made sense, but they puzzled me!) which is a switch interface that can handle 128 toggle
    switches or 64 pairs of push buttons. The module talks to the CANBUS and tells other things, in this case specific Servos to do something eg. operate points.
  • the module at the left labelled CANSERVO8 (I can understand this one – it controls 8 servos!) listens on the CANBUS and when it gets a message relevant to the points it controls – it talks to the particular servo concerned, and alters its state (normal or reverse). The servos do the business.

It’s interesting to note that the previously mentioned 4 wires seems true here (2 for CANBUS and 2 for 12DC to power modules, servos, lighting etc). But what about the DCC bus? That’s another 2 and it’s very prudent to divide the layout into SUB buses for DCC.
For example, Brolgan Road has 4 sub buses – loco, yard, carriage works, main station area and a number of isolating areas controlled by microswitches to isolate the areas either side of the lifting entry flap. Then, of course the servos have to be connected to the CANSERVO by cables and so it goes on!
BUT – if you are methodical and use colour coding and write a master list, then wire neatly and use labels, all will be well.

The video above shows a test rig built on a board being used to move a servo, in this case to find its centre position. The test rig consists of two Pocket Money Projects (PMP). The one on the left is a “Servo Controller/Tester” and all it does is respond to the position of the control knob (operating a variable resistor). It allows me to make sure the servo arm is fitted in the correct position – giving equal movement each way.

The PMP on the right as called “Ezy Points” and you will see it working in the video below. It is connected to a turnout test bed so that I can test the movement of the point blades. The 3 BLUE objects on the circuit board are variable resistors (aka potentiometers aka “pots”) which adjust 3 things manually with a screwdriver: speed; movement Left; movement Right, so that you can make the poin blades “kiss” the stock rail.

These PMP projects are fully described in the free book “Electronics for Model Railways”

An earlier test rig (below) better shows the “pots” (blue) and the standard RC (radio control) cable – yellow, orange, brown. You can get these in various lengths from hobby shops dealing in RC aircraft. Or, you can buy them on eBay very cheaply. You can plug them together for longer runs.
If you had a tiny shelf layout with a couple of points, you could use a few “Ezy Points” to control them. OR – you could use the servo to activate any other moving thingy eg. a gate, a signal etc. anywhere on your layout. Of course then you haven’t got remote control of all aspects like you have with CANBUS (or DCC).

The servo cable would normally come out the bottom of the layout.
Here is a close-up of the CANACE3 printed circuit board (PCB). You can buy the complete kit from MERG or just the PCB as I do and source the parts locally.
The soldering is not difficult but it requires practice. I will try to develop a VIDEO showing the process.
This is a close-up of the CANSERVO8 and this is a beautifully designed PCB of a more modern style. This board can control 8 servos and 2 are plugged in at the top. The long device in the centre with lots of legs is an IC and it can be purchased pre-programmed. It has all the “smart stuff” that responds to signals on the CANBUS and then bosses the servos around!

Controlling Mains Power on a Layout

This is a simple topic and one which may be of no value if you have a tiny layout.

In my case, with a layout running around the walls, I had 3 mains power outlets all of which would be difficult to access when the layout construction was under way and completed.

This Remote Controller is one of a number that are available which allow you to switch varying number of outlets. This one does the job for me.
Check on-line for pricing (look up: remote control power outlet)

The switched outlet plugs into the wall socket as above. I can turn ON ALL with one switch or select which one I want.
It is also useful for me to divide the layout power into three sections which eases the load when powering up. Others have more than 3 controlled outlets.

Modifying Peco Points for DCC

A Peco Electrofrog point modified for DCC is shown below. I have added the microswitch to the right which changes the polarity of the frog as the point changes. The microswitches were about 50c – $1 on eBay and are activated by the push rod controlled either by:
mechanical point levers
or by servos.
On this page “Point” = “Turnout”  / “Switch”       “Sleeper” = “Tie”The microswitches need to be small – these are 20mm x 10mm x 6mm thick (body size)

These were the microswitches I used but …
… the longer arms on these may have been better (can be trimmed)

The first step is to attach the microswitch in exactly the right spot as shown below.

The critical bits are:

  • I always fit the microswitch such that the electrical switch contacts are towards the “Right” rail which is always a RED wire on my layout. The centre connection  on the switch goes to the Right rail – clarified further down in the YELLOW BOX
  • the hole in the throw bar must be able to operate the lever on the microswitch (and NOT miss it!)
  • the switch needs to be positioned so that the throw bar will operate the switch (hear it “click”) when the points are thrown.
  • the switch is attached using contact cement (in my case Quick Grip). First work out which surfaces of the point and the microswitch will fit together – they need to be scraped or filed smooth for a good bond. I scrape the underside of the point with a blade and file the bottom side of the microswitch to level it (actually, I hold the microswitch and rub it back and forth on a file).

make sure you don’t get glue into the moving parts and hold it with a clamp as in the photo below.

There won’t be any wires on your switch at this stage.

The two bridging wires here need to be prised out. Check the instructions with new points or on their website.

The easiest way to lever the two short wires is with a small screwdriver.

Then put a small amount of flux on the 4 rails shown. Use something like Carr’s Red Label or DCC Concepts Flux – a non-corrosive type.

The 4 rails have had a spot of solder to “tin” the rails and on the left a piece of tinned copper wire has been soldered in place. You can buy that from electronics suppliers like Jaycar.

The rails on the left are bridged and trimmed; the wires in the middle removed; and attention moves to the frog connection on the right.

The wire provided needs to be extended to reach back to the microswitch. Use similar size tinned copper wire. Here the extra wire has been twisted around the original and will be soldered together first then run down the length of the point.

This diagram explains what is happening electrically. In my method, the switch becomes part of the point to feed the correct polarity from the Common connector on the microswitch to the frog – as shown above by the GREEN connection 3.
On my layout, an additional (Light Blue) wire from the Common connection on the microswitch is taken below the layout to be used to indicate which route is set on the panel. This means my panel LEDS show which track has power.

The extra tinned copper wire has been soldered to the point wire and is run in the least conspicuous path. I gently melt the wire into the underside of the sleeper with the soldering iron to hold it in place.

The wire from the frog terminates at the Common connection on the switch – may be labelled       “C” or “1”

The wire from the frog terminates at the Common connection on the switch – may be labelled           “C” or “1”

This rail area indicated has been tinned ready for connection …

…and this one ready for the other side.

As the run is only a few mm, bare tinned copper wire is fine.

Another view.

These wires run through the foam benchwork and connect to DCC (red & green) and the 3rd light blue wire provides a common connection (from the frog) to allow an indicator to show which way the points are set.

The LH connection is the common pole in the SPDT switch (SPDT= Single Pole Double Throw)
The middle contact connects to the red (Right rail DCC wire) and the RH contact connects to the green  Left rail .

This template locates the cut-out needed to accept the microswitch under the point.
The red lines are used to align it to the rails as the switch is off centre. In this case the point was being operated by Wire-In-Tube via the trench shown.

Having marked out the position of the recess for the microswitch, cut the underlay and foam with a sharp knife.

Routing the hole to a depth of 10-12mm with a Dremel (and vacuum cleaner).

Dremel Cutter
Ready for a test fit.

The final steps which can be done after the point is installed:

  • remove the over-centre spring IF you are using servos to control the point – this can be done from the top.
    My points are operated using servo control technology designed by the MERG UK group and built by the user. The points operate at a slow speed and can be set up using a computer interface to smoothly touch the stock rail. See MERG site.
  • leave the spring in place if you are manually switching the point.
  • notice that the sleepers near the mechanism have been thinned down from their over-scale size.
  • if servos are used, the throw bar ends can be cut off.
  • weathering will improve the realism of the installed point.