Thursday, December 26, 2019

Kato D51-498 DCC Conversion

There are two different model number for Kato D51-495 Orient Express'88 model. The first one is the item number 2016-2, with a more detailed cabin and what seems a more detailed model. It is the newest one, but on tracks derails much easily that the old model which is the item number 2006-3. Here you can see my approach to convert to DCC both models:

Starting with the 2016-2 model, it has the very same mechanics than the 2016-9 model that you can see in my previous post:

You don't have to unscrew anything, everything is clipped, and there is plenty of space if you want to use a sound decoder like SD10A form Doehler & Haass. In this case, I decided to use a tiny Zimo MX616 decoder.

Fist of all solder the current wires of the decoder to the current plates of the tender. Don't worry about the length of the wires as there is enough space to hide it. Plates can be easily removed and mounted again with the wires already soldered.

Cabin and main body are removed easily, just with with the help of a thin screwdriver as they are only clipped.

Then pull from the motor wires and un-solder them from the strips that will appear:

Tender weights can be already mounted after passing the motor wires as seen in the following photo. Again, leaving wires too long is not an issue:

Isolate the wires once soldered with Kapton tape:

And this is finally how it looks before closing it:

And now you can compare it with the old model 2006-3, not as well detailed but with a much better behaviour on tracks. To unmount the tender you have to unscrew one of the bogies, don't pull from the tender because in this model it is not clipped. Inside you will see the following piece that is clipped. Here is were you have to solder the motor wires:

To open the main body there is a hidden screw under the very first axle. You will need to move the first axle to one side to access it. Don't unscrew any other screw or you will have a lot of work to put all gears and little pieces in place again...

After removing the motor, cut the motor current plates that are folder to the side. Cut them to do not stand out from the support and avoid a short circuit, and solder the motor wires as you can see in the following photo:

Mounting the whole thing again is a little tricky, you will need three or four hands for it but just be patient and hold everything until being able to screw the bogie under the tender so everything keeps in place. To close the tender you will have to sand a little bit the hull under the front side, where the motor wires pass from the tender to the main body:

Thanks for reading, and Merry Christmas to everybody!!

Friday, September 6, 2019

Kato 7007-2 DF200-50 DCC Conversion

This Kato model has the same light board and structure than the EF66 that I already converted as described in this post. So I just followed the same instructions, but in this case using a Zimo MX616. There is no problem of space, putting the decoder in one of the sides the roof has space for this or even a bigger decoder.

Once you remove the light board, flip the motor plates in vertical position. When you insert again the light board these plates won't be under the board, but over it. You won't need neither any Kapton tape nor isolating any point.

In the following photo I'm showing how to prepare the light board:
  • Red arrow: you have to cut the track in this 3 points
  • Blue arrow: make a bridge between the cooper tracks. First remove the capacitor, and make a bridge instead.
  • Yellow arrow: soldering point, tin these 4 points and the motor plates

Here you can see the decoder soldered and in place:

And that's all, enjoy!!

Sunday, September 1, 2019

SVLocoIO firmware for Arduino updated

A new functionality has been released for SVLocoIO firmware. This is the Arduino program we use for all I/O Loconet modules. This means, it is the main Arduino software to manage sensors and outputs (street lights, layout illumination, ...).

It was missing a functionality that other boards do, which is to inform about the state of the inputs (sensors) at power on. When the command station is turned on, or the power on button of your software like Rocrail or iTrain is pressed, the module will send the current state of those ports configured as input.

With a bit more of technical detail, when a OPC_GPON command is sent throuth Loconet, the board responds a OPC_INPUT_REP message for each configured input.

If you want to deactivate this functionality, delete or comment the line in the top of the code:


I also corrected some errors when calculating the input number of a pin. It was affecting to the debug mode making the input numbers to be printed wrong. With this correction the maximum input number has been increased to 2048.

You can download it from:

If you use this firmware with GCA185 Loconet shield board, remember you don't need the pulldown resistors of the board as the program uses the Arduino internal pullup resistors.

Thursday, August 29, 2019

DIY Simple DCC Command Station for less than 20€

In our last exhibition we missed to have an independent command station to read and write CV. Normally we are managing trains in automatic mode, so command station and Rocrail are busy managing trains and we cannot stop if we need to program a new locomotive or read its data if we don't know the locomotive number it has.

So we decided to make a new module with two independent tracks and an independent command station so we can read, program and test locomotives. This module will be in the operator's side, connected to the "T" module that we use to enter or extract compositions to the main tracks.

We took profit of the fantastic DCC++ project, and just changed it to add a display, keypad and slider so we don't need the PC to perform any of the above operations before running a train in the main layout.


Before continue reading, please consider the following typical disclaimer for DIY projects that applies to all this blog:

DIY projects are purely “at your own risk”. As with any DIY project, unfamiliarity with the tools and process can be dangerous. Posts should be construed as theoretical advice only. I’m not a professional, but only a hobbiest passing on ideas and tips to other hobbiests. Information and techniques I show here can change, and there can be mistakes in the information I publish, so I’m not responsible if that happens. Please consider my instructions as a guide only.

Shopping List

Arduino MEGA 2560 R3, 5€

L298 Motor Shield, 5€

4x5 matrix Keypad, 1€

Slide Pot, or linear potentiometer, 1€
We chose a linear potentiometer, but it can be a regular button potentiometer or any other kind.

20x4 LCD display with I2C controller, 6€

A bunch of DUPONT cables for the connections, 1€

Two power sources, one for Arduiono and an independent one for the motor shield. We recomend a 16Vdc 3Amp power source for the motor shild, as we found with less voltage some decoders do not respond to CV commands, or sound decoders do not work properly.


Please check first my previous post about how to mount the original DCC++ command station here ( Motor shield needs some preparation (cutting a pad and making a bridge between pins 2 and 13).

After that you can connect the new elements (keypad, display and slider pot) as shown in the following scheme. Take into account that the keypad of the scheme is not the correct one (we are using the 4x5 keypad, see photo above these lines), but I couldn't find the Fritzing object for the right keypad:

  • Display needs 5V, GND and two wires to SDA and SCL pins of Arduino (pins 20 and 21)
  • Potentiometer needs 5V and GND in the same way, and the signal is connected to A8
  • Keypad is connected using 9 pins (from 22 to 30)
  • You will need one power source for Arduino, and an independent 16Vdc power source for the motor shield


You will find always the latest version of the program to upload to the Arduino in the following link, were you can freely download from ClubNCaldes github repository and upload it to the Arduino Mega board:

How it works

I tried to make it as much intuitive as possible, but this are the main keys:

"*" ON, tracks are feeded with current
"#" OFF, no current to tracks
"F1" RUN MODE, this is the mode to run and test trains
"F2" PROG MODE, this is the mode to read and write CV in the programming track

In RUN MODE the left and right arrow are used to set the direction of travel, while the numbers activate or deactivate the functions. Speed is controlled with the slide pot.

In PROG MODE you can see a little help in the last line of the display which tells you the meaning of each CV entered (just for the standard ones like address number, acceleration, break, config...)

I hope you enjoy this simple but useful DCC command station for you own projects.

Thursday, August 22, 2019

Kato D51 2016-9 DCC with sound

I don't know if Kato planned this model to be easy to convert to DCC, but it seems so. I converted several D51, but this is the easiest one and has a lot of space to add sound also.

The weights in the tender are not occupying all the space and you can add a SD10A decoder and a small speaker from D&H. I purchased them in

If using SD10A decoder, first you need to solder some small cables to the SUSI pads to connect it to the D&H programmer. I couldn't find a specific D51 sound project, but some steam projects have similar sound to the original one as I could check looking for videos in Youtube.

This custom board you see between the decoder and the programmer is just to help with the connection and testing of the sound decoders. I made it to be able to connect the sound decoders with screw terminals, and it has also a speaker. I think the design of the D&H programmer is awful when referring to the connection, programming and testing of sound decoders. It is missing screw terminals and a test speaker. It's not a cheap device and connection of decoders is horrible so better make a small helper board like this one.

Once the sound is programmed, we can come back to the decoder installation. Here you can see were to solder the current wires, red and black ones:

In the following photos you can see how it fits in the tender. Remember to isolate the decoder with Kapton tape and pass motor wires (orange and gray) throw the existing hole like in the photos:

Finally, cut the motor wires (or remove the cooper plates used by the motor to pick up the current) and solder them to the orange and gray cables of the decoder. Ready to test:

I found using this decoder that the locomotive was not running smoothly, it was instead advancing in fits and starts. This was fixed changing CV56 (Motor proportional controller) to value 0. 

This CV has something to do with what Doehler & Haass calls "Super Soft Drive". It seems a kind of motor auto regulation, doing some pauses between current pulses to the motor and measuring it in order to adjust the pulse width (or something like that....). But the fact is that it drove me crazy until I could find a clue about it and deactivate it.

Sunday, June 16, 2019

Kato 3047-3 EF66 First Version

This is a quite fast digitalization if you have experience in Kato electric locomotive models:

My common strategy is no do not flip one of the led lights when they are SMD components. In fact, it is not possible to solder them again if you turn them upside down, as the solder pads are just in one side. So the solution is to modify the board to reroute the current as needed:

First of all detect which is the positive lead of the led, and this must be connected to the current after the resistor. Then you have to isolate the negative lead and this will be connected to the white and yellow wires from the decoder.

One easy way, and with no danger, to detect which is the positive and negative side of the led is using a tester or polimeter in diode or conductivity mode. This is the mode where it beeps when current is passing without resistance. Touching the led with the tester pliers will make it light slightly when in the correct place. This is the red plier in the positive lead, and black plier in the negative one.

Here you have indications showing where I cut the cooper tracks (3 places, in red) and were to make a bridge between tracks (blue):

I used in this case a DH05 decoder form Doehler & Haass, purchased at

And that's all, no need of sanding or making place in the shell as this decoder fits well in the position you see in the photo, and if you reroute wires properly:

Sunday, May 5, 2019

Kato 3045 EH200 DCC Conversion

I've been always scared about "double body" locomotives, but you will see this EH200 model from Kato is pretty easy and straight to convert to DCC:

Light boards have no capacitors, so there is no need to remove any component. The only needed modification is to make sure that the positive lead of both leds is connected to the resistor. One of them has to be turned for that. The negative lead has to be cut and solder here the white and yellow wires from the decoder as seen in the following photos:

First of all, you need to isolate motor plates from the current pick up plates. The easiest way is using Kapton tape:

I'm using a very small decoder, a Doehler Haass PD05A-3. I found the best position is the one shown in the following photo. Even here, a bit of sanding will be necessary:

Better than sanding the lead piece, if you coot the roof it will fit and nothing will be seen with the plastic piece over the top shell:

And that's all, enjoy!