Atlantic's works: Portable layout - Scenic details next

[manna]

G'Day Gents

Bl**dy Brilliant.

manna

[nzpaul]

G'Day Gents

Bl**dy Brilliant.

manna

Yes, that pretty much sums it up.

Paul

[Hatfield Shed]

Here's a brief return to the main frames of the four-coupled drive unit I mad last year. Front is on the left in this view. With wheels off this side, the frame profile is visible, which as far as I can tell from the only drawing I've been able to view is correct. Note the rather artistic curvature of the lower edge of the frames between the axles, with (I presume) the flat-bottomed ash pan showing below that curve. Note also that the curved cut-out is not mid-way between the two axles, it is offset towards the front.
STA72115.JPG

Such an interesting detail. Suggests someone in Gorton's design shop thinking well ahead of his time. And thanks for the overall exposition.

[Dave S]

Very nice Graeme, and your moulds always look tidier than mine.

[earlswood nob]

Good day all

Very interesting...........

Excellent detail............

Malcolm

[Atlantic 3279]

The Parker (Kitson?) designed tenders had only open rails at each side of the fireman's work area, unlike the solid extensions to the fronts of the sidesheets on Robinson's versions, so I had been unable to include those in resin casting - far too flimsy for that sort of thing. Last night I considered a practical way to make a reasonably neat, strong set in metal with a secure attachment to the resin. Reliance on glue alone seemed very unwise and even those who preach that "thou shallt solder everything" cannot solder metal to resin. My first move was to use some 0.45mm nickel silver handrail wire to form something that looked like miniaturised paper clips, gone a bit wrong.

In positions carefully marked to match the lower edge of the cab side cut out, the long leg of one of those looped wire whatsits was then inserted into a hole drilled in the front of the tender, inset from the edge. Holes for vertical handrails were also drilled in the front of the soleplate, after using the wire loop as a marking guide.

With a loop fitted to both sides and the verticals inserted it looked like this.

A little solder was then used to fill the void in each wire loop, soldering the tops of verticals in place too, with care taken to keep them looking upright and parallel. The reason for having the short "end" of the wire loop turning back inwards aft of the rear vertical rail should now be evident, as that assisted with keeping that rear rail upright and it meant than minimal heat and solder was necessary to fill up the spaces at the rear of the loop, in close proximity to the resin.
With handrail tops cropped off and the solder filed smooth I was happy enough with the result.

[Woodcock29]

Continuing excellent work Graeme
Andrew

[73082gibbers]

Very impressive Graeme! Looking forward to seeing the finished result!

Nathan...

[James Harrison]

It's looking the part! Did I see a tender cabsheet/ spectacle plate in one of the earlier photographs?

[Atlantic 3279]

You did, but as it is certainly fragile in resin I'm not fitting it until most other jobs are finished. I could have made the tender weatherboard thicker for greater strength, but I didn't want to spoil the appearance, given that even the thin resin version is thicker than true scale. There is of course the option to use two, each with one face rubbed flat and the two stuck together if strength is the overriding requirement.

[Horsetan]

The non-ideal mould for the tender soleplate that I mentioned a little earlier:
STA72109 col adj.jpg

The outer mould for the boiler, which has to split along the bottom centre line of the boiler in order to allow the projecting base of the cast smokebox to be extracted:
STA72110.JPG
Here it is with the (inverted) core piece. That core piece has a "plinth" at the firebox end, which functions in the same way as the plinth I used in the running plate mould, controlling the depth to which the core piece is inserted, and since it is trapezoidal in shape it cannot be put in the wrong way round. The conical tip engages with a conical depression at the smokebox end of the outer mould, ensuring centralization of the core piece and even thickness of the cast boiler walls. That is essential for even, adequate strength and to ensure that the small boiler can sit centrally over a motor of reasonable size.
STA72111.JPG
The interlocking stepped contours of the rubber I created on each side of the split, by careful arrangement of thin shuttering before poring the rubber, plus supporting clips cut from stiff card, keep the split closed when resin and the core piece are introduced into the mould.
STA72112.JPG

It's the boiler moulds I find most fascinating.....

[Atlantic 3279]

The next image may help then...

After passing through the "slow fiddly details" stage, my first D7 from resin castings is considered just about complete, bar paint and final adjustment of weight. Brake shoes, guard irons, lamp irons, additional handrails, smokebox door fittings, buffers, slots for coupling hooks, proper crankpin fixing washers and some further attention to gaps in body joints have enhanced the appearance since last seen on here.
Also in the image, some of the master parts for comparison, including the boiler as prepared for mould making, i.e. with motor cut-out covered by a thin skin, same added to square-off the base of the firebox, also to form a cone just within the front of the smokebox, plus, a length of thin shuttering formed into a zig-zag section and pinned to the full length of base of the boiler. The latter of course was required in order to form a tidy, interlocking split in rubber mould, vital for final release of the boiler castings from a mould also capable of staying the right shape while holding liquid resin.

[Atlantic 3279]

The only evidence I've seen regarding the rear of the 3000 / 3080 gal Parker tender, in a drawing I borrowed, suggested that only a horizontal handrail was fitted, without the two additional vertical ones seen on the larger Robinson tenders, hence that is all that I've fitted to this model. No rear guard irons were apparent in that drawing either. Should anybody know better, please speak now...

[Woodcock29]

Just superb Graeme.
Andrew

[9E]

The only evidence I've seen regarding the rear of the 3000 / 3080 gal Parker tender, in a drawing I borrowed, suggested that only a horizontal handrail was fitted, without the two additional vertical ones seen on the larger Robinson tenders, hence that is all that I've fitted to this model. No rear guard irons were apparent in that drawing either. Should anybody know better, please speak now...
STA72138.JPG
STA72135sm.jpg

Graeme

The two photos of D7 tender rears in the relevant Yeadon show vertical handrails. Both these tenders (those attached to 5684 and 5687) show these handrails and a full set of visible rivets etc and so appear to be Parker tenders.

Regards,
Simon