Faux Concrete, tarmac and cobbles

This was the scenic part of the model we were dreading. How do we go about raising the level of the ground so that it is level with the top of the rails, which looks authentic and is easy to apply. Well as hinted in a few posts a go, we decided to use the method of flooding the raised areas with DAS Modelling clay.

A test piece was done to find out how we can realistically pattern the cobbles in the clay. The end of a Biro with the writing bit removed, is too big to make cobbles in n gauge, but would you believe it that the actual nib of the pen (non writing side), with the plastic ink tube removed, makes the perfect fit (if a little oversized) for n scaled cobbles. Luckily the area for cobbles at Thornycroft is relatively small, so all in all it took about 45mins of "prodding" the clay to lay the cobbles.

The clay was laid in handful chucks squished down onto a watered down PVA adhesive layer, and then levelled using a stainless steel metal ruler, block of smooth wood, and finger squishing. Although we could never get it perfectly flush and flat. Concrete slaps were scribed into the surface, and a sprinkling of fine sand to create the tarmac surfaces.

The clay was then squished down between the track and sleepers, making sure we kept the top of the rail clean, and the sides deep enough for the trains wheels. Although due to shrinkage the sleepers have left an imprint in the clay. Another thin layer should hopefully reduce this affect.

The buildings fit nicely in their holes, although a few required tweaking with a knife, to square of a few side. The cardboard formers with sticky-back-plastic edges worked pretty well.

It took 3 afternoons so far to get to this stage, and 2 Kg's of DAS clay. I think it was worth it, it has certainly brought the model together.

Painting up next, and working out how to apply the clay in the turn outs and still keep them working. Interesting conundrum.

Ed

Behind The Scenes

One of the sidings on our Thornycroft layout goes through a large factory building but most of this building is 'off stage'. A small fiddle yard sticking out behind the back scene is needed to accommodate wagons sent into the factory.

For layout transportation (it is portable) this protrusion needs to be removed. The first idea was to put it on a hinge that folds flat to the baseboard frame. However, in practice the give in the hinge made the assembly too sloppy for accurate track alignment. A more rigid arrangement was needed and the method that worked best was a single stud screwed into the end with a wing nut and washer holding it firmly against the baseboard frame.

Some error of squareness crept in that lead to the assembly taking on a downward slope! This was compensated for by two small wood screws screwed into the end whose heads act as stoppers.

The wiring to the track should be on a plug and socket to facilitate complete removal of the assembly but for expediency it was permanently wired. For transportation the assembly is unscrewed and simply laid on the top of the baseboard in a non scenic area with a strap to hold it down.

David

Track Laying For Thornycroft Sidings

Track laying is complete for the scenic side of the layout. Such a simple statement that hides a more complex exercise than expected.

Track is Peco SL300 (code 80) with insulfrog turnouts. The turnout to the yard is medium radius and those within the yard are small radius setrack. Ordinarily I would use at least medium but small radius is used in the yard to save on space.

Care was needed to ensure the relationship of track to buildings was correct because the track follows the outline of building profiles. A lot of fiddling and adjustment was needed to ensure locomotives traverse the turnouts without derailing, which is a particular problem with small radius turnouts and the Dapol M7 tank loco. (More about this here.) It is a bit of a worry because the track work is to be buried in faux tarmac and concrete, which will not allow us to make track adjustment later.

In the photo the footprint of buildings that are to be set below ground level are marked with temporary raised platforms of 4mm corrugated cardboard. This sets the boundaries for the roadways to be made from DAS modelling clay that will be laid between to a depth of 4mm.When the platforms are removed the buildings should slot into place.

We still need to do more locomotive trials through turnouts and adjust for smooth running before letting Ed loose with his DAS clay over this lot.

There is more track laying to do behind the back scene and loops laid for each end that make the oval circuit.

The next photo shows the business end underneath the baseboard. Five of the six Seep point motors were obtained cheaply second hand - a great deal, until I discovered that the operating pins had been cut for a lower baseboard height than ours! Several pins had to be hammered out and new pins made from straightened paper clips glued in place and cut to our height requirement. I used Seep motors rather than Peco as they are easier to mount on a baseboard.

In order to get the turnouts to switch effectively varying degrees of loose fitting of the motors helped. In other words they work better with a loose fit to the baseboard rather than being firmly screwed down, except for one turnout where I had to weaken the turnout spring. (More about this here.)


David

Thornycroft Dunlop Van

I mentioned earlier that a bodied version of the A1 chassis was on the agenda. I wanted a van that had a colourful livery with simple logos.

The Thornycroft Register has an amazing portfolio of vehicle photos. However, the 1920s/30s photos are all monochrome. Livery colours cannot be determined easily.

The Dunlop van caught my eye due to its simple branding. There is a George V 'by appointment crest' beneath which are the words 'By Appointment', the Dunlop  brand name and the words 'Rubber Company Co. Ltd.'

But what of the livery colours? I came across a photo of a Dinky toy Dunlop van in red, desaturated its colours in a graphic editing Application and compared the result to the Thornycroft Register photo. The grey shading was a perfect match! Further confirmation was needed and  a couple of 1930s Dunlop brochures were found where red featured. We can see from the Thornycroft photo that the roof is a lighter colour. One of the brochures showed the Dunlop name in black with a yellow border.  so, I assume the roof was yellow.

Here is an unkind photo of our N gauge model. Its roughness is far less noticeable when viewed from the normal distance of 2' or more.

Its chassis construction was described in a previous posting. The body is 3D printed in plastic and covered with paper overlays designed in a graphic editing Application. Windscreen glass and steering wheel are included as are headlamps and spare wheel underneath on the other side. The number plates carry the number of the Dunlop van in the Thornycroft Register photo.

Here is a very close up photo of the corporate branding. It occupies an area less than 10mm square.

On the layout I intend to park the van outside the factory in Worting Road with the Thornycroft photographer in attendance, thus capturing a typical scene shown in may of the vehicle photos.

David

Lunch Box Controller 2

Following on from the success of our portable Cliddesden Lunch Box Controller I made another one for Thornycroft Sidings. This time the train controller is a separate unit, which is the black box in the photo of the previous posting below. I kept the train controller separate so that it can power Thornycroft and Cliddesden track if the two layouts are connected together. This lunch box only provides turnout control, except 3 track power feed switches for sidings are included (independent wiring from the turnout control).

The polythene lunch box came from Sainsbury supermarket at £1.50 and takes hole drilling for the switches very well. The finished unit is comfortable to hold and easy to operate.

The electronics inside (capacitive discharge) were lifted from my 00 gauge layout as it was redundant, having opted for manual control when the track was changed from EM to 00 in 2008. The circuit design is shown in the March 1981 edition of Everyday Electronics magazine. Circuit designs can also be found by searching the web.

The cabling is 8 way CAT 5 of which two runs were needed plus a single wire. 25 way D's connect the unit to the layout under the baseboard.

The black wire is the 15 V DC feed for the turnout electronics.

David

Baseboard Bank Holiday update

Reading back over "The Book", we realised that the track running past the site heading towards Basingstoke is a 1 in 82 incline, levelling out in the middle and heading towards Worting Bridge a 1 in 50. This meant that we had to raise the track level, and introduced some ramps on the curves at the ends, as the track had to end level with the back where the siding goes into a building. The track bed was raised using 6mm and 12mm MDF, cut to size, sanded and plained down to produce the ramps and inclines. On the downside to this, the track level is now higher than Ciddesden, which means we'll have to create a new inter-scene-section to join them together (whenever we decide to do that). As with Cliddesden we painted the ends, back and sides jet black as they are not part of the prototype, and it draws the viewers eyes to the main layout.

As you can also see from the above picture we have also began laying the track.
To attach the ends to the main board, we decided to utilise our 3D printer, David drew up a design for a latch using CAD software and set the 3D printer to work making 4 of them. To help with alignment we also added in two dowels in each side. Hopefully this design will make it a lot quicker to set-up and tear down.

Ed

Thornycroft A1 Chassis - 3D print

Whilst waiting for Ed to find time to work on the baseboard (phase2)  I skipped from phase 1 to phase 3 of the project to see how well our 3D printer could make a Thornycroft A1 chassis in N gauge.

A1 Class

Introduced in 1924 the light weight A1 had a load capacity of 1.5 tons. It was sold as a chassis for customers to add their own body work or supplied with bodywork from Thornycroft's range of styles. A war department subsidy of £120 was available to customers who opted for it, which meant in times of need the War Department could requisition the chassis with or without bodywork at a reduced price from owners. The book price of a chassis in 1926 was £460.

The Model

It was very common to see vehicle chassis in the yard at Thornycroft so it is the chassis that I initially wanted to make. A dimensional drawing is available from Hantsweb and the kit of parts I drew up in FreeCad.

The kit comprises:

• Wheels
• Front Axle
• Rear Axle
• Engine compartment
• Chassis with built-in cosmetic leaf springs
• Drive shaft with gear box
• Steering wheel
• Steering column
• Gear lever
• Petrol tank
• Exhaust pipe

Quite detailed for N gauge.

The paint finish of the assembled chassis is a big unknown because only monochrome photographs have been found and most of these suggest a lighter than black colour. I have not found any written records of the stock finish. I assumed they would have been stocked in primer paint to be finished in the customers livery before dispatch. I chose a red oxide colour (Humbrol 100) but grey may have been used in reality.

The chassis will be positioned outside the paint shop on the layout.

All the parts are so small that if they are 3D printed individually the plastic filament does not have enough time to get flowing before the print finishes! So I ended up making a batch of 5 for greater coverage! 

They turned out better than expected and I'm looking forward to making a bodied version and some other vehicle types. I quite fancy one of the six wheeled lorries.

David