Building and completing my 4mm 3D Printed GNR Coaches

[MikeTrice]

Non step end drilled for handrails:

 

Likewise the sides. For these I used a scriber tip to press into the resin to mark where the holes should be drilled:

 

 

Shortly after doing the step end rails my supply of 0.4mm N/S arrived from Eileen's Emporium with their usual speedy service. Handrails formed with the help of a Bill Bedford Handrail Bending Jig and superglued in place (from behind where possible):

 

 

Really not happy with these, they are all over the place. Descriptions such as "dog's dinner" "pig's ear" and worse spring to mind, so having slept on it decided to take remedial action which will be covered in the next post.

Edited March 23, 2018 by MikeTrice

[FPH 603]

Just stumbled across this thread and these coaches you're building look great. I follow with interest!

[Atso]

Despite your concerns about the handrails, I think that the coach is looking great! Have you thoughts about putting the holes for the handrails into the CAD model?

Edited March 23, 2018 by Atso

[MikeTrice]

There are "dimples" for the handles and grab rails. I thought I had included some for the Full Brake but I think they were too small to come out. I must admit I will probably revise the model once I have gone through everything to include pre-drilled holes.

 

It is only the Full Brake has these issues as for the other coaches all the dimples are present.

[MikeTrice]

Wonkey handrails removed, holes enlarged and new handrails fixed in place. In some cases I used the non-engineering principal of using a drill bit to saw/file the openings down/up:

 

For the special handrail by the guard's door I origianlly used two separate handrails but they did not look very good so I resorted to soldering the horizontal to the grab handle. I seem to have got away with it:

 

I now have lots of little holes where the handrails enter the body. To attempt to fill them and disguise my mistakes I used Deluxe Materials Perfect PLastic Putty. The holes were filled with a toothpick and then a wet brush used to tidy up. Also shown in this photograph is the additional guard's handle that opens the right hand door. These were produced using 0.7mm N/S bent to an "L" shape then the outer face filed flat:

 

The finished side:

 

The end handrails have also been fitted:

 

And after a light spray of primer:

 

The handrails fitted so far are all to be painted black, hence why they have been  fitted now (good job given what happened). The door handles are brass so will be fitted after painting and graining.

 

OK, not exactly a silk purse but I think I have managed to bodge my way out of trouble. Just the other side to do now for which I have a cunning plan (hopefully) which will result in greater accuracy. Watch this space (but don't hold your breath).

Edited March 23, 2018 by MikeTrice

[gr.king]

In some cases I used the non-engineering principal of using a drill bit to saw/file the openings down/up:

 

OK, not exactly a silk purse but I think I have managed to bodge my way out of trouble.

I'm thoroughly familiar with such uses of a drill bit!

 

Does the end result have to be a silk purse? I know it's nice to get things looking perfect, but how many of the real coaches were kept in perfect order in service conditions?

[micklner]

So do you just solder the handrail to the tip of the wire?

 

Yes araldite the plate to the coaches inside, more than strong enough and will resist the heat whilst the handrail is attached unlike superglue.

[Compound2632]

Mike, did you do that soldering on or off the model? What heat will the material stand?

[MikeTrice]

The soldering was on the model for the special handrail. It was a tiny amount of solder that was applied quickly to a fluxed joint. I would not like to hold it there for long.

 

P.S. I did put a couple of slivers of paper under the joint to protect the side and hopefully keep the two handrails level with each other..

Edited March 23, 2018 by MikeTrice

[MikeTrice]

Just like Baldrick's my cunning plan did not work. Basically I attempted to use a pair of dividers to space the mounting holes from one edge but there was still too much variation. Back to the drawing board.

[MikeTrice]

Well cunning plan number 2 did work and should have been what I did straight away. I used a x3.5 headband magnifier and a desk lamp to actually see what I was doing!

[MikeTrice]

I have mentioned that I use a Bill Bedford Handrail jig to bend the handrails so a slight diversion in how I use it.

 

Following a series of trial and error handrail bending I have finally hit upon the following method which has proved far more reliable. First off measure with a pair of dividers the distance between the inner edges of the holes, e.g the inner length of the handrail:

 

To find which set of holes in the jig to use measure the equivalent distance from the dividers:

 

I have used 0.4mm N/S for the handrails so start by bending one end through 90 degrees:

 

Insert the bent tail into the inner hole of the jig. Notice that the wire is thinner than the hole in the jig so it is important to pull the wire against the inner edge:

 

Holding the wire against the jig just check where the tail exits at the back. IT will probably be at an angle so swivel it round until it is square:

 

Again holding the main wire firmly into the slot in the jig bend the other end:

 

There is a fair chance that the resulting "staple" still does not have parallel legs. If not grip the short leg in a pair of pliers and twist until they line up:

 

Trim to suit.

 

Using this technique I have managed to bend all the handrails and grab handles for the second side without a single mistake.

 

 

 

[MikeTrice]

I made a very slight change to my approach for fitting the handrails on the second side in that before bending the 0.4mm N/S wire I rubbed it with wet-and-dry paper to take off the shine in an attempt to improve paint adhesion.

 

The grab handles are bent up in the BB jig:

 

The main part is then gripped in a pair of pliers:

 

The tails are then bent to an angle (not really so obvious in this picture):

 

The finished grab handle:

 

The handrails are fitted to the side and spaced using pieces of 10thou styrene:

 

Likewise the grab handles:

 

In most cases the tails of the handles poke out on the inside of the coach so they have a small drop of superglue brushed on to fix:

 

For the handrails at each end of the sides where the tail cannot pass through the side one tail is trimmed back:

 

I was asked earlier how I did the soldered joint for the special handrail. First off the grab handle was fitted in place:

 

The horizontal piece was bent, trimmed and the right hand end superglued in place with a suitable spacer:

 

My soldering equipment. An Antex iron, Templer's paste and fine resin solder (in this instance from FastTracks in Canada):

 

A tiny piece of solder is cut from the reel with a blade:

 

A card spacer (in this case the header from Eileen's N/S wire) is placed under the joint, then paste flux applied and the tiny piece of solder placed on top:

 

Holding the horizontal handrail in place a very quick touch of the iron is enough to allow the solder to flash over:

 

The joint can now be cleaned up:

 

Here is the second side with all handrails in place and more importantly square. A great improvement over my first attempt. Just the Guard's handles to add:

 

For the guard's handles small "L" shape 0.7mm wire is bent up:

 

The wire is held in a drill chuck and the visible face filed flat:

 

Finally the hendle is trimmed to length and the end shaped:

 

A 0.7mm hole in the side allows them to be fitted.

 

 

 

 

[Compound2632]

I'm curious: why add the handrails etc. at this stage and in nickel silver, rather than after final painting (but before the last coat of varnish) and in brass? I confess ignorance on the details of GNR livery but I assume that the real things were polished rather than painted brass? 

[MikeTrice]

In this instance the prototype are painted black so wanted to prime them. The door handles which were brass will be added after painting.

[MikeTrice]

Difficult to work out what to cover next. I have started the underframe but am having to wait for delivery of further supplies, so instead I will cover more on the body.

 

For the full third I thought I would try an alterative method of doing the curved handrail. I started off drilling the holes and bending a "staple" that was inserted from the rear:

 

The curved handrail is bent using the jig and superglued at the lower mounting points:

 

The rail was aligned spacing it from the end and soldered in place:

 

After clean up it was pushed back into the body and the handrail superglued from behind:

 

In spite of my reservations it actually worked very well.

 

The handrails on the other end were also added:

 

The bodies were then sprayed in Filler Primer to prime the handrails.

 

For the roofs I fancied reproducing a livery that seems to be rarely modelled, i.e. when the first 20" of the roof above the cornice was hand painted "teak".

 

So first of all I applied some 6mm tape along the roof above the cornice:

 

A second strip was then applied adjacent to the first:

 

With the second in place the first strip can be removed:

 

The side masking tape is trimmed back and small strips applied carefully across the ends:

 

The brake roof was slightly harder as the strengthening ribs stop the tape laying flat. The tape either side of the ribs was slit with a scalpel and any gaps filled with Humbrol Maskol:

 

I could now start applying the base colours for the teak finish. In this instance as I wanted a slightly darker finish I used a mix of Vallejo Bright Orange (70.851) and Orange Brown (70981).  Flat Brown (70.984) was dry brushed over the panels to give some variation to the panels:

 

 

 

 

With the roofs masked I did something that might seem counter intuitive: I sprayed them white! The theory is that and bleeding under the masking will occur with the white paint which as it matches the underlying colour should not be visible. Once dry they were sprayed with Filler Primer then given a Bright Orange/Orange Brown base coat. Being hand painted I did not add the darker dry brushing:

Edited April 1, 2018 by MikeTrice

[MikeTrice]

The teak base coat has now been given a coat of Klear and the parts will now be put to one side to cure.

[MikeTrice]

With the base coats dry time to get out my "teaking" kit; Liquin Original, Vandyke Brown oil paint and a flat brush. I normally use Burnt Umber oil paint but wanted something slightly darker:

 

After mixing the Liquin and oil paint on an old tile it was applied roughly all over the coach body:

 

Next the vertical panels were grained by running the brush up them trying to avoid getting a build up of paint at the panel edges:

 

Finally the horizontal panels were treated as were the roof edges resulting in:

 

and

 

 

Unfortunately the lighting does not do it justice but I am happy with that. Now put to one side for at least 24hrs.

 

[MikeTrice]

I am convinced there is a black hole in our house. You would not believe the number of times I have bought something, and then it has disappeared into the black hole and I cannot find it again. There are at least two items required for this project that I know I have had but are no longer to be found.

[teaky]

I find that if you buy the items again the lost ones turn up straightaway.

[gr.king]

I am convinced there is a black hole in our house. You would not believe the number of times I have bought something, and then it has disappeared into the black hole and I cannot find it again. There are at least two items required for this project that I know I have had but are no longer to be found.

Ah, but you can try out some satisfying Old English words and phrases while looking for them.....

[FPH 603]

With the base coats dry time to get out my "teaking" kit; Liquin Original, Vandyke Brown oil paint and a flat brush. I normally use Burnt Umber oil paint but wanted something slightly darker:

IMG_4100.JPG

 

After mixing the Liquin and oil paint on an old tile it was applied roughly all over the coach body:

IMG_4101.JPG

 

Next the vertical panels were grained by running the brush up them trying to avoid getting a build up of paint at the panel edges:

IMG_4103.JPG

 

Finally the horizontal panels were treated as were the roof edges resulting in:

IMG_4107.JPG

 

and

 

IMG_4110.JPG

 

Unfortunately the lighting does not do it justice but I am happy with that. Now put to one side for at least 24hrs.

Well looking at the photos it looks great. I bet they look much better in person!

[gobbler]

I am convinced there is a black hole in our house. You would not believe the number of times I have bought something, and then it has disappeared into the black hole and I cannot find it again. There are at least two items required for this project that I know I have had but are no longer to be found.

I have one of those.......

 

Annoying aren't they???

 

Grrrrr!

[timbowilts]

I have one of those.......

Annoying aren't they???

Grrrrr!

 

A “black hole” is an essential component of every modeller’s tool kit :^)

 

Tim T

[MikeTrice]

Graining coat dry followed by another coat of Klear then masking removed. Slight bleeding at ends however these photos in a rare patch of sunlight show the colour much better.