Lubricating, Oiling and Greasing Locomotives

As well as 3D printing model trains and building model railroads, I do a lot of repairs to locomotives for fellow modelers. These range from simple wire repairs up to total motor and chassis rebuilds or replacements.  One of the issues I come across is over lubricated locomotives, so in this post I will tell you a bit about why this is a problem, and how it should be done.

Some people have said that liberally lubricating moving parts will help preserve them if they are going to be stored for a long time and I can assure you this is not the case.

Over lubricating a locomotive can have the following progressively worsening effects:

It can cause the locomotive to lay a film of lubricant on the rails making the locomotive and others loose traction.

It can make it slippery to handle and possible damage the paint work.

It can make it easy for the mechanism to retain dirt and fluff, which will start to cause binding and over strain the motor.

Oil inside the motor, or on the commutator, can disrupted the flow of electricity to the motor making it run slow or roughly. (What is a commutator? see the image below).

Oil inside the motor on the armature can connect parts of the motor to the power or chassis causing arcing and bad running though intermittent shorting. (What is the armature? see the image below).

And the biggest problem, oil coating the commutator and brushes which will cause a dead short.  This will in turn cause the motor to overheat and burn out; this is when the small gaps between the commutator plates blend into one, so the electricity just passes straight through.

I often get locomotives to repair where there has been smoke coming from the motor or a glow and buzz, rather than turning.  This is normally a sign that the motor has become jammed or the commutator is shorting.  The glow is lubricant and carbon, from the brushes, stuck between the commutator plates acting like a bar fire element.  The smoke is usually the excess oil burning off from the heat being produced. If the commutator or brushes are heavily lubricated electricity simply doesn’t go where its supposed to.  Sometimes if a motor gets to this stage it can get deformed from the heat and will never run as well as is should again.

One other issue I sometimes see is if the wrong type of lubricant has been used.  Some are not plastic friendly and can cause gears and parts to break down.

So what should you do?  The simple answer is ‘just a few drops will do, don’t over lube’ and this is the phrase on the package of the main lubricant I use from LaBelle.

Being an N Scaler I tend to use lubricants from LaBelle as they have a set designed specifically for N scale which are plastic friendly and very fine, but the principles are the same for all scales.

The three products in the kit are oil, gear lubricant and grease.

LaBelle 108 is a very fine oil with a high viscosity.  It is used, sparingly, for moving metal components like valve gear and side rods on steam engines.  It can also be very sparingly used on motor bearings and brush slides etc. but try not to get any on the actual brushes or commutator. (LaBelle 107 is designed more of larger scales such as HO and O).

LaBelle 102 is heavier than the oil but not as thick as grease and is designed for exposed gear boxes.  It contains PTFE (Polytetrafluoroethylene) which has been called “the slickest substance known to man” and is the parent chemical of “Teflon” which is a registered trademark of Dupont Chemicals.  It’s great for metal gears and axles.

LaBelle 106 is a grease, which also contains PTFE.  Their slogan is ‘just a dab’, and they are right.  It’s designed for plastic gear boxes and worm gears.  A dab on one of the gears will work its way through the box and onto any worm gear.  Again, a dab is all you need, over lubricating with grease could start to bind the gear box.

There are lots of companies making similar products, and any good model shop should be able to guide you to the right one for your model.

But which ever you decide to use, remember just a drop is enough.

Fitting DCC to Wrenn OO Locomotives – Vertical Motors

Last week’s post was all about converting Wrenn OO locomotives with horizontal motors to DCC; you can find the post here.  This week I’m going to share with you how to convert the vertical motors.

The vertical motors were used in the City & Duchess 4-6-2s, A4 4-6-2s, 0-6-2 tank engines, Royal Scott 4-6-0s and Bullied Pacific 4-6-2s.  The two engines I’m converting are the ‘City of Birmingham’ and ‘Sir Nigel Gresley’.

To remove the all-metal shell simply remove the screw located at the front and it will come away from the chassis.

As with the horizontal motored locomotives the wiring is very simple.  The black wire goes to the right side pickups and connects to the isolated motor brush at the front of the motor.  The brown disc is the capacitor which acts as a suppressor to prevent interference with televisions etc.  The other wire from the capacitor connects to the chassis and the left side pickup.

All the wires are removed except the black feed from the right side pickup.  The brush at the rear of the motor is not isolated from the chassis and, as with the horizontal motor, it’s this one which gives us a problem.

The steel cap covering the brush simply pulls out to reveal a spring and a brush as below.

The cap fits into a brass sleeve which guides the brush and spring to the armature.  In order to isolate the brush from the chassis this sleeve will have to be removed and replaced.

It’s very unlikely the sleeve will push out; you may be lucky but chances are it will need to be drilled.  Before you do this the armature will need to be removed to prevent damage and metal filings getting where you don’t want them.  In the picture above you can see I’ve removed the magnet and side plates: this is done by removing the main bolt through the motor.  The front brush should also be removed by pulling the end cap out.  Then the top nut above the armature can be loosened and unscrewed.  Note there is a small ball bearing in the cap. The grease should hold it there but be prepared for it to fall out. Then the armature can be removed, normally from the right hand side.  There’s also a small ball bearing in the fitting at the bottom of the armature. Again, it should stay in place but be ready just in case.  The chassis should then look like this.

Using a 5mm drill the old sleeve can be drilled out and the hole made ready for the new 3D printed sleeve; you can see the new sleeve in the bottom right of the image above.  Once the hole has been drilled, clean and remove any burrs from the hole and remove any metal fillings from the chassis.  Before you fit the new sleeve make sure the brush fits through without any resistance.  It should be able to fall through if tipped up.  If it sticks there may be some 3D printing residue inside which can be removed with a drill bit or round file.  The new sleeve can now be fitted and, if necessary, held in place with a little glue.

Then simply reassemble the motor.  Before you put the armature back in check to make sure the ball bearing is still there.  The top nut should be screwed down so the armature spins freely but has no vertical movement; only then should the nut be tightened.  With the brushes refitted, a continuity test should be done with a volt meter to double-check that both brushes are isolated from the chassis.  Then the wires can be added for your DCC decoder.  The red goes to the black wire, the black goes to the chassis, the orange goes to the front motor brush and the gray goes to the rear as below.

Once a DCC test has been performed the shell can be refitted and the loco is good to go.

So where can you get these 3D printed isolating brush holders? They’re available here:

Two Wrenn horizontal motor isolating sleeves.

Four Wrenn horizontal motor isolating sleeves.

Two Wrenn Vertical motor isolating sleeves.

Four Wrenn Vertical motor isolating sleeves.

Two Wrenn Vertical & two horizontal motor isolating sleeves.

I will also keep a few in stock so please drop me an email or message me through the contact page.  If you have a different locomotive which needs a special part to isolate the motor for a DCC conversion I’d be happy to look into it for you.

Fitting DCC to Wrenn OO Locomotives – Horizontal Motors

This week I’m going to share with you a simple way to add DCC (Digital Command Control) to older Wrenn OO locomotives.

Wrenn locomotives date back to the 1960s but don’t be fooled by their age.  They’re very good models and are still widely collected and run.  If you find one in its original box it may even be worth a lot of money, depending on the model inside.

One of their main advantages is they’re all metal, making them very heavy.  This gives them a lot of tractive effort compared to models produced in later years.  The mechanisms are simple but well-built which means most of them are probably still running well.  However these were all designed well before the concept of DCC came along so the motor wasn’t isolated from the chassis.  In fact one of the motor brushes is connected directly to the chassis which makes converting these to DCC a problem.

But to overcome that problem I’ve come up with a simple way to easily make the conversion.  The Wrenn locomotives I’ve come across have one of two types of motor; horizontal and vertical.  This week I’ll cover the horizontal motor which is in the 8F 2-8-0 as pictured bellow, the Castle 4-6-0 and the Rebuilt West Country 4-6-2 which is the locomotive I shall be working on today.

The Rebuilt West Country has the motor and all the wires located under the shell.

With the shell removed you can see a single black wire, which runs from the right hand wheels, connecting into the green wire and going to the right motor terminal.

The left terminal is connected to the chassis by a metal bolt.  Both terminals are linked by a capacitor which acts as a suppressor to prevent interference with televisions etc.  Each terminal also has a spring which keeps pressure on the motor brushes inside the brush holders.

The brush holder on the right is isolated from the chassis and is only connected to the green wire.  The brush holder on the left is the one which gives us the problem.  In the image below I’ve released the spring and the brush has fallen out.  Be carefull not to drop the brush as they are made from carbon, just like a pencil lead, and can easily crack.

The brush holder is made from brass and is fixed directly into the chassis, making a perfect electrical connection.  The brush holder should pull out with a pair of pliers as I have done below.  If not, it will need to be drilled out; if you have to do this dismantle the whole motor first, because you don’t want to damage the inside or get metal filings in the armature.

With the brush holder removed it’s a simple matter of replacing it with something which works as an insulator.  And the answer is a 3D printed brush holder.

These have been designed to be a direct replacement.  They are 3D printed in Shapeways’ Frosted Ultra Detail material and should fit into the hole with a push.  It’s important to check first that the brush slides freely inside the holder.  Any print residue inside may cause the brush to stick and this will prevent the locomotive from running.  Any residue can be removed with a drill, the same size as the brush, or a round file.  If the brush holder is a loose fit in the hole simply fix it in place with some superglue.  (Superglue is made from acrylic and so is the Shapeways FUD)

The black wire from the right hand side wheels has been cut and will be joined to the DCC decoder.  The capacitor has also been removed.  Under the left motor terminal is a bolt which also connects this side back to the chassis; this needs to be removed and left out.

At this stage a continuity test using a volt meter is a good idea to ensure the two terminals really are isolated from the chassis and both left and right wheels.  If they are, then the brush can be re-fitted and the spring clipped on to hold it in place.  The wires from the DCC decoder can now be soldered to the motor terminals.

The power feeds can now be connected; one goes to the black wire and the other to the chassis.  I connected the chassis wire to the screw holding on the weight at the front of the loco.

And that’s it, the loco is chipped and ready for testing.

Next week I’ll share with you how to isolate a vertical Wrenn motor and where to get the 3D printed brush mounts from.

Changing Sounds on Digitrax Sound Decoder – Part 2

In last week’s post I shared with you a simple method of changing generic sounds on a Digitrax sound decoder and how to adjust effects like volumes.  You can find the post here.  This week I’m going to show you step by step how to completely change the sounds so you can make them match the locomotive you’ve installed your chip into.

To do this you will need an extra bit of DCC equipment supplied by Digitax; their PR3 or PR3EXTRA as pictured below.

This device is designed to connect your computer to your layout to allow computer control or to simply allow you to communicate with your other Digitrax DCC products via their LocoNet system.  It can also be used, along with your computer, as a stand alone programmer and that’s what we’re going to do.

Depending on what computer you have and what operating system you’re using, your PR3 may need to have a driver installed, which can be downloaded from the Digitrax site here.  Once installed the PR3 is connected to the computer with a USB lead and requires its own power supply, which comes with the PR3.  There’s a small twin screw terminal block on the front of the PR3 which is where you connect wires for your programming track.  As I’m often doing this at shows I simply have a strip of track with two wires soldered to the end.

The next step is to download and install the software to your computer.  Again this is supplied by Digitrax and is called Soundloader and can be downloaded here.

The current version, at time of writing, is v2.2.  When you first open the software you get a window that looks like this.


At the bottom of the screen it says ‘Could Not Open COM Port’.  This is because it doesn’t know how your PR3 is connected. At the top of the screen on the drop down menu is ‘COM Port’.  Select this and it will open a window with a drop down menu.  Providing your PR3 in installed and plugged in it will list the com port which you can select.  Then the screen should look like this.


The software is now ready to use.  When you place a locomotive on the programming track the software will automatically pick up the DCC decoder and interrogate it, as you can see below.  The software is finding out what sort of decoder it is; this is important as different decoders are capable of different things.


Once complete the software will display the information in the bottom left of the screen.  This decoder is a 16bit Series 6.  It also tells me the size of the flash. This is the amount of flash memory, just like a flash drive or SD card you use to store photos in a camera.


The next step is to get your sounds or sound project for your locomotive.  There are a few places where you can get them from but the main place is Digitrax’s website here.  Sound Projects or SPJ files are not official files, that is to say they are not produced by Digitrax, rather they are created by the Digitrax user community and shared though the site.  Another place to get sound files and support is the Digitraxsound Yahoo Group.  This is a great site to ask advice and help solve any issues.

Once you have downloaded the file you want you can load it into the software by selecting file and open.  The screen will then look similar to this.


The big green button tells us that it’s ready to download the Sound Project to the decoder.  If this button is not green then there’s an issue. This could be because the SPJ file is for a different decoder or there’s not enough room on the decoder for your file.  For this example you can see the ‘Flash Download size’ is 341248 Bytes and the ‘Decoder Free Flash’ size is 1769472 Bytes, so we have plenty of room. By pushing the green button three things will happen.  First, the software will erase the current flash on the decoder; normally the speaker makes a squealing sound when this happens, so don’t panic.  Second, the software will download the SDF files; these are the command files which tell the decoder what the sounds are.  And third, it will download the Wav files; these are the actual sound bytes and this process takes the longest.  Below you can see a screen shot of this happening.


Once complete, that’s it.  If you put the loco on the tracks it should play the new sounds.  However there are a few traps which you can fall into which may prevent it from working, so I like to use the Sound Test tool first.  This can found on the drop down menu and when opened looks like this.


In the image above the Sound Test tool is still reading the decoder.  Once complete you should be able to push the relevant buttons and the sound decoder will respond.  Another nice feature is you can engage the forward and backward motion to hear the steam chuffs or engine sounds, but the loco won’t actually move.  In the screen shot below you can see I’m testing the forward motion with F4 & F7 switched on.


If however you find you get to this stage and you still don’t getting any sounds there are a few things to check. In last week’s post we discussed CV60 which changes between the different sound sets.  If, for example, you had previously set the decoder to set 3 and then flashed in a new SPJ file, set 3 will be empty as the new SPJ will load into set 0.

If this still doesn’t work it may be a problem with the SPJ file.  I had a similar problem to this recently and was able to get the help from the Yahoo Group.  If an SPJ line within the file is not assigned it can cause issues.

Looking again at the screen shot below you can see one of the sounds, 006 DEISEL_RUN_HI, is not assigned.  By right clicking on this you can select ‘Restore Association’.  If it had previously been assigned it will correct itself.  However, if nothing changes right-click again and select ‘Assign Silence’.  This will make it associate with a Mute file.


Once the SPJ file has been updated it can be re-flashed onto the decoder and this time all the sounds should play.

As I mentioned before the PR3 can be used to communicate with other devices via the LocoNet system and this is something I will share with you in a later post.

Changing Sounds on Digitrax Sound Decoder – Part 1

In October last year I showed you how I fitted a Digitrax DCC sound decoder and speaker into the tender of an N scale steam locomotive, you can read the post here.  At the end of the post I mentioned that when the locomotive was put on the track and powered up, diesel sounds played instead of steam.  In this post I’ll show you how this can be changed.

As standard, Digitrax sound decoders come with pre-installed sounds, normally for generic diesel and steam locomotives.  These are also for US outline locomotives so they may not be ideal if you model trains from other countries, but as a generic they’re not too bad.

There’s a simple way to change the generic sounds and adjust the volumes. And there is a slightly more complex method which allows you to totally change the sounds, which then enables you to use them for other countries too.

The first and simplest method is to switch between the diesel and steam sounds and, for many, this is sufficient.  This is done by altering the value of a certain Configuration Variable or CV.  CVs are the electronic switches within the DCC decoder which control all the options such as the locomotive’s address, light functions, maximum speed and sounds.  The majority of DCC controllers or command stations have the ability to read and changes these CVs.

I won’t be able to give you instructions on how to change the CVs on your particular DCC controller as there are so many different makes and models, and they’re all a bit different. However you should be able to find out how to do it from your operator’s manual; it’s normally under the decoder programming section.  The good thing is the principle is basically the same for all.

Normally this involves placing your locomotive onto a programming track.  This is a section of track which is totally isolated from the rest of the layout and only connected to the programming track output on your DCC controller or command station.  Why do this?  Well, if you programmed through the main track feed it will talk to all of your trains at the same time. Also the programming track has a much lower power output, so if something is wrong it shouldn’t damage the decoder.  There are ways to program specific locomotives on the layout by ‘programing on the main’ but I’ll discuss that at a later date.

With your locomotive on your programing track, ask your DCC controller to read CV60.  This is the switch which tells the sound processor which sound set to use. If CV60 = 0 then it will use the steam set, if CV60 = 1 then it will use the diesel set.

So if you’ve installed the sound decoder in a steam locomotive and CV60 = 1, follow the instructions for you DCC controller to write or change CV60 to 0.  Then, when you put the locomotive on to the main track, it will play the steam sound set.

Using this basic method of altering CVs you can also alter other sound related functions. CV58, for example, is the master volume.  As standard it’s set to 9 but can be increased to 15 if required.

Below is an extract from a Digitrax Sound Decoder manual showing some of the CVs which can be adjusted.  I would recommend being methodical when doing this as changing the wrong CV can cause the decoder to behave in a strange way. In the event that it all goes wrong and you don’t know what you did, don’t panic!  There is a simple way to reset the decoder back to factory settings.  This is done by setting CV8 to 8.  Please note that not only will this reset volumes and sounds to the diesel set but it will also reset your locomotive number to 03.  This is is definitely something only for the programming track.


I like to increase the master volume as well as the whistle and prime mover/steam chuff sounds but leave the bell turned down.  I find the bell a bit annoying!

One thing to consider, if you set the volumes so they’re just right for you at home, where it’s probably fairly quiet, you may find if you take your trains to exhibitions or club nights the sounds may get drowned out by the background noise.

But what if you don’t want your locomotive to sound like a generic US steam engine; what if it’s a British LNER A4 or German Ice HST?  Well, that can be changed too using the slightly more complex method I spoke about earlier and in next week’s post I will show how to do it, step by step.

A Way to Paint FUD & FXD 3D Printed Parts

I regularly get asked how to paint the Shapeways 3D printed Frosted Ultra Detail and Frosted Extreme Detail materials.  There are several methods that work but I thought in this post I’d share with you the method used by one of my fellow modellers, Chris Broughton.

Chris produces fantastic models, such as his Baldwin RT-624 as shown below.

RT-624 Button

This model has been made from one of my kits 3D printed at Shapeways in FXD. The kit arrives as shown below, except for the handrails which are fixed inside the shell for protection.

Baldwin RT-624 Kit

Chris also used my etched brass Addition to complete the model.

Baldwin RT-624 Additions Render

From here I will let Chris explain his method for painting his models;

“First, I soak the parts in Bestine to removed the waxy coating from the parts. I’ll leave them in for 2-3 days, since the Bestine doesn’t harm the parts. When the parts come out of the soak, I’ll rinse them in water and lightly brush them with a toothbrush.

PPR RT-624 (Chris Broughton) 1

Once they’re dry, I’ll lightly sand any areas that have a coarse texture from printing. In areas where there’s detail, I’ll using small sanding sticks and try to work around the details.

PPR RT-624 (Chris Broughton) 2

I use Tamiya Fine Surface Primer to prime the parts. If more sanding is necessary, I’ll sand and recoat with the primer.

PPR RT-624 (Chris Broughton) 3

As for paint, I’ve been using TruColor paint more recently. I’m used to using Floquil, so I’ve had to adapt since they’re no longer around.

PPR RT-624 (Chris Broughton) 4

I’ve been pretty happy with TruColor, but I get the best results over a primed surface, and it has to be thinned quite a bit for airbrushing (to the consistency of water). I just use 100% acetone fingernail polish remover for thinning and cleaning. The paint goes on glossy, which is great for applying decals, then spray with Testors Dullcote from a spray can to seal the decals and weathering, and give it a matte finish.”

PPR RT-624 (Chris Broughton) 5

Chris’ finished locomotive looks fantastic which just goes to show how well his method works.

PRR RT-624 8355(Chris Broughton) 3PRR RT-624 8355(Chris Broughton) 2

Many thanks to Chris for sharing his painting method and for the excellent photos.

Last week I had promised to share some new products with you and I will be shortly, I’m just making a few last minute adjustments.  As for this coming weekend I’m going to the NMRA (BR) Benson Winter Meet and hopefully I’ll have some photos and videos to share with you from the show.