Alco C-855 R-T-R Build – Part 2 – Grab Irons

This week I’ll be continuing my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post will be about the first details to be applied to the shells; the grab irons.  You can find part one of the build here.

The grab irons or hand rails are small parts but form an important detail.  For these models I’ve made them from etched brass rather than a part of the 3D printed shell.  I could make them a part of the shell but they would be extremely fragile and probably couldn’t withstand being handled without breaking.  The other option’s to make them a solid piece of the shell but I find that makes them look too bulky.

The grab irons are located in the etched brass frets as shown below.  There are two sets for the A units and one for the B unit.

Each 3D printed shell already has the holes to locate all of the grab irons, and other parts.  Below you can see the cab of the A unit with the various holes.

And the rear also has holes for the four grab irons which create the ladder to the top of the locomotive.  Both ends of the B unit are the same as the rear of the A.

There are two types of grab iron.  Straight and folded down and in the A unit fret there are eight of each, although you only need 7 of the straight ones.

The straight ones have half etched sections where they are connected to the main fret to allow them to be easily cut out with a sharp knife.

One thing I strongly recommend is to test fit each grab iron.  If the hole is clogged or the grab iron is slightly bent the wrong way and you attempt to glue it right in, one leg will stick and the other will bend and you’ll be left with a wonky grab iron.  Each grab iron fits into a pair of holes which are either all the way through the shell or just the right length. So if you’ve cut them out too close to the fret and they are too long they may stick out too far.  This is another good reason to do a test fit.

The folded down version also has half etched sections on the rear just after the corner.   This allows the grab iron to easily be folded down in the right place.

I find by using a pair of wide tweezers I can hold both the legs and simply bend the fold down section into place with my finger.  When I tried it the other way round it was hard to get both legs in the right place.

I tend to get all the grab irons ready together, but I keep the two types separated.

To secure them in place I use superglue.  This is a great choice, not only because it sets very quickly but it is a type of acrylic and so are the 3D printed shells so there’s no danger of a chemical reaction damaging the shell.  I wouldn’t recommend trying to apply superglue directly to the shell; that normally ends in a sticky mess.  The best way is to pour some onto an old box lid or something similar, then gently dip the tips of the grab iron into the superglue just before you place it into the holes.  After you have test fitted it of course.

The straight grab irons fit in the A unit cab in six locations; I know there are only five shown below, I forgot one but it will appear shortly.  There are two in the roof above the number boards, two in the face of the cab above the outer windows, one in the side of the nose, above the step area, and finally, although not shown yet, one on the top of the nose.

The seventh fits in the top of the shell at the rear. The last one is simply a spare.

Three of the drop down grab irons fit into the side of the nose under the straight one.  These are the only three which don’t fit into two holes; the rear leg of each grab iron does but the front simply glues onto the front of the nose.  There is small sections of the 3D printed shell which stick out to locate the grab irons which sit on top of them. There is a fourth fold down grab iron under one of the windows.

When complete the fronts look like this. The B unit front is the same as the rear.

And the rears look like this.

The B unit fret has eight fold down grab irons and two straight ones.

So why have I only fixed the grab irons and not the rest of the etched brass parts?  Well these are the most delicate to do and also these need to blend in when the locomotives are painted. All the rest will be fixed after painting as they either fixed to several different parts or will make painting the shell harder to do if fitted first.

These shells will now go in for painting and while that’s happening I’ll turn my attention to the chassis which I’ll share with you next week.

Alco C-855 R-T-R Build – Part 1 – All the Parts

As promised in an earlier post I’m going to share with you the process of building an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post is the first one covering all the parts.

I released the C-855 kit back in the beginning of 2016 and have made a few since then but as a fellow modeller has asked me to make a complete set for him, two A units and a B, I decided to document the whole thing to help others, as this build is a bit more tricky than normal.

So where to start?

I guess the best place is to show you all the parts you will need.  This will include 3D printed parts, donor parts, new parts and etched parts.

The 3D printed parts, as shown below, are all supplied by Shapeways in their Fine Detail Plastic material; originally called Frosted Detail Plastic.  This material is available in two quality levels; smooth and smoothest. The difference is the layer thickness, Smooth being 29 microns and Smoothest being 16 microns.  The Smoothest option takes longer to print and is therefore more expensive.  Since releasing these models Shapeways have also introduced their option to set the orientation of prints so the best detail can be achieved in the areas where you want it.  However, this also comes at a higher cost and as these engines are so big it did make a considerable difference to the price.  So I offer them in orientated and unorientated versions.  To find out more please see the C-855 page here and the C-855B page here.

The parts 3D printed in Fine Detail Plastic, starting from the top, are:

  • C-855 Locomotive Shell
  • C-855B Locomotive Shell
  • C-855 Locomotive Shell
  • 3 Fuel Tanks & 6 Drive Shaft Extenders
  • 18 Sand Boxes
  • 4 Special Sand Boxes, 4 Crew, 3 Sets Of Horns, 4 More Sand Boxes & 3 Fuel Tank Mounts

Since arriving from Shapeways all the parts above have simply been rinsed under warm water, soaked for twenty-four hours in Goo Gone, rinsed again in warm water, left to dry for forty-eight hours and finally run over lightly with a brush in a Dremel style tool as shown below.

I use this tool as any residue left over from the print process turns to powder after contact with the Goo Gone; once dry the brush simply knocks it off.

The next set of parts is the chassis.  For these locomotives, if you want them to be powered, you will need to get a donor chassis from a Con Cor U50 or turbine.  This is the only thing currently available which is even close to the C-855 chassis.  However it is too short and needs to be lengthened.  I will cover that later.

The parts for the chassis, starting from the top, are:

  • 3 Con Cor U50/Turbine Donor Chassis
  • 3 Sets of 3D Printed Stainless Steel Chassis Extenders
  • 3 New Kato Motors

The chassis extenders are also 3D printed by Shapeways and can also be found on the C-855 page here and the C-855B page here.

The new motors are not necessary for the build but the old Con Cor motor, although reliable and strong, is rather noisy by modern standards and this particular Kato motor works well as a replacement.  You can read a post about swapping them here with and an update here.

The last set of parts, well almost, is the etched brass parts as shown below. These are etched in 12 thou brass to give strength to the long parts.

Each etched set of C-855 Additions, as shown below contains:

  • 7 Handrails
  • 16 Grab Irons
  • 4 Ladders
  • 3 Walkway Platforms
  • 2 Sun Visors
  • 4 Windscreen Wipers
  • 4 MU (Multiple Unit) Hoses
  • 2 Miscellaneous Pipe Sections

The etched set of C-855B Additions, as shown below contains:

  • 8 Handrails
  • 10 Grab Irons
  • 4 Ladders
  • 3 Walkway Platforms
  • 4 MU (Multiple Unit) Hoses
  • 2 Miscellaneous pipe sections

The only other thing I’ll need for this build is three DCC decoders, LEDs for headlights and relevant wire but I’ll come to that in a later post.  I’ll also start working on the preparation of the parts leading up to the assembling of the locomotives.

This week I’ll finish off by saying I, along with my club members and club layout ‘Solent Summit’, will be at the Great Central Railways model railway exhibition from the 15th to the 17th June 2018.  You can find our more here.  And if you time it right you’ll see an A-B-A set of C-855s running on the layout.

A Different Way to Resurrect A Shelf Queen

As promised in last week’s post this week I’ll show you a way to give some new life to old steam engines, or any locomotive which has became a ‘Shelf Queen’.

The phrase ‘Shelf Queen’ is normally used in model railroading to describe a locomotive which looks great but just doesn’t run well and spends all its time on the shelf.  This could be because it has a broken part, it doesn’t pull well or simply runs so roughly or erratically it’s frustrating.

I have several of these which I kept telling myself I would get around to fixing, but time marches on and I now find myself with newer locomotives which outstrip my ‘Shelf Queen’ to the point that if they where good as new they would still disappoint.

So what to do with them?  The answer is make them into a scrap train.  Now I know I said “give some new life to old steam engines” and sending them for scrap is sort of the opposite!  But it’s a model, so they will forever be on their final trip to the scrap yards, and will be running on the layout once more.

I have several engines to do this with but the first three, as pictured below, are a pair of original Bachmann 4-8-4 steamers with long haul tenders and a Con-Cor 4-6-4 streamlined Hudson. (The Hudson in the image is not the actual locomotive, this one is good runner.)

The first thing to do is to remove any motors, drive shafts, wires, connectors and pickups.  Both of these locomotives have gears between the drive axles which I’ve left in to ensure equal turning of all the wheels.

Once this has been done and the locomotive has been reassembled it’s very important to ensure it’s free running.  That is to say when pulled, or pushed by another locomotive all the wheels freely rotate and any side rods and valve gear don’t stick.

Often when steam locomotives are transported like this the connecting rod, which links the piston to one of the driving wheels, and the eccentric rod, which drives the valve gear, is disconnected or removed.  This prevents damage occurring to the cylinder as it is normally lubricated by oil in the steam.  However these are going for scrap and Bachmann only linked the rear three driving wheels together with a side rod; this is the horizontal rod linking all the driving wheels, probably to save material as it can’t be seen behind the connecting rod.  But with the connecting rod removed it just looks wrong so I left them on.

It’s also a good idea to sort out any couplings at this stage so the effect of ageing the locomotive is all over.  New shiny couplings stand out.

To transform these locomotives into rolling wrecks on their last journey I handed them to my friends at Model Railway Solutions who went to town with a mixture of weathering powders, paints and a few secret ingredients.

And now they look like this.

Once these have been weathered to this severity all moving parts will need to be re-checked to ensure they still run free.  Areas like the valve gear are particularly susceptible but simply running the locomotive vigorously up and down your hand will free most of it up.  The biggest issue is paint and material on the running face of the wheel.  This will cause the loco to bump down the track; in real life they would be smooth as they weigh hundreds of tonnes.

However once it’s all ready the effect is fantastic, here are three powerful modern locomotives taking two giants on their last trip.

The Hudson still had some crud on the wheels so even these three diesels struggled to pull all the steamers, however in the last frame of the video it’s on the back of the train.

I intend to extend the train with some of my other ‘Shelf Queens’.  Some of these will have the connecting rods removed, maybe a tarpaulin over the cabs, rusted holes in he tender and maybe the word ‘scrap’ painted on the side.  Something else to consider: a lot of steam engines come with coal molded into the tender; of course this would not be here and the coal bunker would be empty.  Also the side rods and parts would still go to scrap so these could be on a flat car trailing behind.  Of course the scrap yard may not be the destination, they could be heading for preservation.

Next week, once I’ve recovered from this weekend’s exhibition in Bristol, I’ll share some of the show with you.

Specialist Brick Feature for an S&D Signal Box – Part 2

In December last year I shared with you my designs for some special 3D printed brick feature details for a OO Somerset & Dorset Railway Signal Box at Bournemouth West Station; you can find the post here. In this post I’ll share with you how they came out.

This brick features, which I mislabeled as a ‘brick castellated feature’ last time, is called ‘dentil’ brickwork from the Latin ‘dens’ meaning ‘tooth’.  It’s a simple form of corbelling.  I printed the parts in strips on a sprue in Shapeway’s White Strong & Flexible material, as you can see below.


The actual construction of the signal box hasn’t started yet but the modeller, Steve Knight, has made a mock-up to see if the parts will work.


The wall has been made from layered card with the brick finish plastic card on top.  The top dentil and bottom sloping brick sections are simply glued in place.

sd-dentil-brick-work-3 sd-dentil-brick-work-4

The whole section is then painted brick red.

sd-dentil-brick-work-5 sd-dentil-brick-work-6 sd-dentil-brick-work-7

The brick details really stand out and, once weathered, will look wonderful.  As I said at the start this is only a mock-up for the signal box, but the image below gives the idea of how it’ll look on the layout.  All the track work and details, like point rodding, have already been finished.


Once Steve has completed the box I’ll share the result with you.

This weekend is the Bournemouth N-Trak Convention which I’ll be attending, hopefully on both days.  You can see videos and photos from a previous visit in 2014 here. I intend to take lots of photos and video this time as well so I can give you a nice full post next week for those who can’t make it.

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.

Replacing the Motor in A Con-Cor Turbine/U50/C-855 Chassis – Additional

Following on from last week’s post about replacing the motor in a Con-Cor Turbine/U50/C-855 Chassis, which you can find here, I have a few updates to share with you.

This chassis has been around since 1973 and has undergone very little change.  However there have been a few, and the more I work with them the more I find.  One of my fellow modelers, Mr Mike Musick, who wrote the guest article about changing the wheels in these chassis, has discovered that the most recent version released under the Rail Baron label has a different motor cradle and the new Kato/Atlas motor will not fit.  You can find Mike’s guest post about the wheel sets here.

The problem with the cradle is solvable by removing the part which clashes with the motor.  Mike says ‘This plastic is hard and not trivial to work with, a Dremel with a small burr bit is about the only way to remove enough material.’  Below is Mike’s photo of a modified cradle.


Mike also goes on to say ‘When removing the old motor, be sure to note the location of the “white stripe” on one side of one magnet. This indicates motor polarity, and the new motor should be oriented with the white stripe in the same relative position. This is especially important if it is not going to be modified for DCC;as with DCC if you get it backwards you simply swap the orange and gray wires.

The original motor in mine came with a 0.010″ shim in the motor cradle. So I swapped it out for an 0.020″ shim, which turned out to not be enough, it should be a total of 0.030″.’

The shim raises the motor as discussed in last week’s post, however too much will cause the gears to bind.

With the C-855 extended chassis Mike has also experimented with not gluing the cup gear extenders, shown below, into the cup gears.  This ‘in Mike’s words’ ‘lets the adapter cup gears “float”, which turns them into sort of a constant-velocity joint and may also influence the noise by reducing gear pressure’.

C-855 Chassis Extenders 11

These small changes can greatly affect the running of the locomotive  by improving noise reduction and smoothness of the motor.

Bob’s three C-855s, from last week’s post, have now all had their motors swapped out for Kato Atlas Motors and I was able to catch them this weekend running through Solent Summit station.  I haven’t added any sound to the video so you can hear, or rather not hear, the motors.

Next week’s post will be on Boxing Day here in the UK so it will be nice and short but for now I would like to wish everybody a Merry Christmas.