Atlantic's works: Portable layout - Scenic details next

[manna]

G'Day Gents

Lovely work, I do like a a 'cute' 4-4-0.

manna

[Woodcock29]

Hi Graeme
The D7 is certainly coming along very well now.
Should you wish to fit sprung buffers - the best GC versions I've found are the Kean Maygib 14" GCR buffers available from Branchlines, but I guess you probably won't. It looks like they had backing plates on the D7s as well.

Andrew

[Atlantic 3279]

Thanks to both of you.

I've thought the D7 looked "cute", ever since I first saw a photograph of one in 1920s LNER green livery standing behind the sea-front shops and cafes at Cleethorpes.

I hadn't begun to think about buffers, but now they've been mentioned it occurs to me that my "bits boxes" contain a selection of packets of buffers, picked up on attractive terms from A. N. Other's unwanted pile, and there are a few Kean Maygib items in there, possible even GC type.

[Atlantic 3279]

Prior to making the cab roof and upper front, I'd already had suspicions, when looking at the model from the side with accepted "horizontal" lines for comparison, that the boiler might be sitting a touch lower at the firebox end than it was at the smokebox end. My slight dissatisfaction with the relationship of the cab spectacles to the firebox shoulders made me look yet again, and check some measurements very carefully. Convinced by that process that the firebox top was too low, I've added some material to its lower edges, giving no more that 0.5mm increase in height, but I feel that I can now accept that the boiler top is level when the loco is on the track, and that the relationships around the cab spectacles are much more acceptable. The strips representing the beading around the cab-side cut-outs are now in place too, ready for later dressing / trimming. The ends may need careful drilling to take the extended vertical handrails that also support the rear edge of the roof.

[S.A.C. Martin]

Really is a beautiful looking model Graeme. Excellent work.

[Chas Levin]

Another appreciative reader here: beautiful model!

[Atlantic 3279]

Thanks again.

Not before time, a few more of the details of the D7 are now receiving attention. I had resisted the addition of any permanent features below the level of the running plate angle irons at an earlier stage as I wanted to be able to place the whole body on a flat surface from time to time as an aid to getting everything straight and square. Now however, I've added the front buffer beam from a couple of layers of plasticard, along with the pieces that help to brace it - the shaped parts of the valances immediately behind its edges and the forward-most parts of the main frames more centrally. I've also added the valve chest front cover in front of the base of the smokebox, from three layers of plasticard filed up to shape.

At the other end I've drilled the necessary holes and inserted the vertical cab handrails, from straight steel piano wire, at least as a temporary measure. These have helped me to check both by sight and by measurement that the rear extremities of the cab all align, also revealing initially that I had managed to get the rear edges of both cab side sheets leaning slightly to the right, resulting in immediate correction! General strength and squareness of the rear end has now been further bolstered by the fitting of the drag beam and a basic representation of the cab floor. Boxes over the rear wheels will further brace things in due course. Such drawings as I can consult tell an incomplete story but I get the impression that one box at least, on the drivers side, may have had a lower part of its top towards the rear, providing a place to sit immediately behind the screw reverser. If anybody knows more about this I'm keen to hear...
I've also managed to create a resin representation of the upper part of the backhead, after several attempts to get a clean, complete, undistorted plasticine impression of a backhead in another completed loco model. Frustrating as it was when I was trying to get the not-new plasticine to bind together properly rather than crack and crumble, then to mould properly around the backhead features, and finally to peel away without stretching too much or tearing, I suspect it was still less trouble than trying to use mould-making silicone rubber. Preventing that from leaking into other parts of the model would not have been easy, nor would rectification of some of the possible consequences of any leaks.
I'll make up the lower part of the backhead to fit between the wheel boxes, keeping it detachable, then make a new rubber mould for the complete backhead in a suitable moulding box.

[Atlantic 3279]

I now have my doubts about the possible lower area for the driver to sit on one of those boxes over the rear wheels. It looks to me as if the driver would then be sitting just 15 inches above the cab floorboards, not ridiculously "squat" perhaps and well shielded by the cab side, but not great for manipulation of the reverser or for seeing the road ahead through the cab spectacle. On the other hand.... at full flat-top height the box top is about 30 inches above the floor boards, so probably not too high for the driver to comfortably perch and better for the view ahead, but sitting side-saddle there he would have cab side behind him to only 7 or 8 inches above seat level, i.e. most of his back unsupported and open to the elements.
As this is "only a model" I think I'll go for flat-topped boxes for simplicity, given that it is impossible to make the central cab space wide enough in a OO gauge model anyway, so no matter what I do it won't be completely correct!

[Atlantic 3279]

A little more D7 progress has been made. Having decided to ignore the evidence in the drawing of a possible recess in the top of the box over the rear wheels (which may perhaps have been covered by a lid anyway) I made up the basic box structures and then realised that because of the way the design of the model has evolved, I could actually fit a solid lower portion to the largely missing cab front too. I had originally kept that area clear, partly in case there were problems getting the motor in and out of the body, but also because I had considered the possibility that resin duplication might require the cabsides and splashers to be produced in separate moulds rather than integrally with the running plate. I do not now think that will be necessary.

What I clearly still have to do is to complete and fit the backhead, as well as making up a representation of the prominent screw reverser. I put the basic upper backhead to one side while I dealt with other things, as I was waiting for delivery of some necessary materials.

I had no brake gear of a kind that looked at all like the right sort for a D7, so I made up some brake arms and blocks from plasticard. Compass cutters were useful for cutting inner curves on the arms, from 40 thou' material. I found it easier to file the outer curves to shape than to try to cut them precisely. A disc of 10 thou' (cut with the sharpened end of a piece of slim brass tube) was added to the arm, and another piece of 40 thou' to represent the block. I'll add a stub of 0.7mm wire to the central hole in each arm in due course.

Those rings of plastic were originally going to form parts of separate crankpin splashers, and they were made by wrapping thin, narrow layers of plastic around a piece of 5/8" brass tube, bonding the layers with solvent. I was trying to get the outer layers to represent beading, so the inner layers had to form a neat, shallow, uniform rebate. I found it a long fiddly job to make them up and I wasn't satisfied with the result, so I devised a different approach. That was to build the crankpin splashers in situ, using pre-curved strip where appropriate, painstakingly trimmed to exact length to fit the apertures in the main splashers. The saving grace for this method was the fact that the curved tops of the splasher apertures helped to keep the curved pieces in place both when trimming requirements were being estimated, and when tiny drops of solvent were being applied. I was glad when the job was completed though, as it involved five separate pieces for each crankpin splasher, each one needing time to stick firmly before more could be added. Naturally, I interlaced the work with other jobs, otherwise the time used up would have been even more excessive.

Although none of it is glued in place yet, for obvious reasons, so it is just the brass wire pushed into holes in the chassis that is holding it all in place, here's a quick look at the rudimentary representation of the brake pulls, with all of four basic soldered joints. The one little complication arose when I assembled the parts dry and realised that the rear yoke might well touch the current pick ups, so I took that out again and put two slight joggles into it, to lower most of the yoke leaving just its ends high enough to fit in the holes in the brake arms.

At least the two sand-filler caps were easy enough to add to the running plate, simply two slices of 2mm plastic rod stuck in place in front of the leading splashers. The two washout plugs on each side of the Belpaire firebox were easy too, needing nothing more than stubs of 0.7mm wire pushed into holes.

Some steps and couple of sandboxes will be needed too before I can declare the plastic-work complete. Guard irons will be from sheet metal.

[Atlantic 3279]

Augmented backhead pattern, in situ.

[Atlantic 3279]

A couple of hours, on and off, this afternoon using a nice large, clear, colour shaded, scaled print of a drawing off the web, two photographs, four pieces of plasticard, four pieces of wire and a surprising number of tools, produced a representation of the screw reverser that was sufficiently "proper" to satisfy me:

[nzpaul]

Yes, I can see a couple of hours disappearing into a piece like that. Must complement you on a lovely set of Ramsbottom's as well.
The plastic brakes are of particular interest, wouldn't it be great if someone manufactured such things. I'd feel much more comfortable fitting plastic bits where close tolerances and potential short circuits exist.

Paul

[Atlantic 3279]

Ta Paul. Do you need some plastic or resin brakes of that particular type?

[nzpaul]

Sorry Graeme, I wasn't meaning to point the finger at you and suggest you should manufacture them. It turns out that Slater's do some LMS brakes in plastic that could possibly be modified to suit purpose.
If one was to consider creating a new product, perhaps something a little more ( dare I say it) generic would be useful. A hanger based on A3s or B1s maybe, the modeller can always make up a shoe to fit their specific application from plasticard, even guys that build weird stuff like NBR locos with their hefty brake shoes.
If you ever do come up with something I'll probably want some, but no pressure.

Paul

[Atlantic 3279]

Had I done the right things, this information would have appeared late yesterday afternoon, but I evidently composed it and then sent it to oblivion...

Of possible interest, there is already one option for resin loco brakes, J6 style:

Returning to the D7, I have now at last managed to complete the last of the plastic cutting and sticking, hence the loco now has its steps and sandboxes. For strength, I originally tried a thick backplate for the steps with tapered inboard edges, but I couldn't get enough taper on the rear edges to get a nice appearance from most angles, without removing so much material that strength would have been lost. Hence I've experimentally taken advantage of the thick running plate structure just within the angle irons, drilling this to take some stiff 0.7mm wire reinforcements onto which thin backplates for the steps can be glued.
Although I've put a set of sand pipes into the temporarily attached sandboxes simply to test the fit and appearance, if I do cast duplicate parts in resin I'll only do the 'boxes. The pipes would be much too thin for resin, obviously, and will need to be added separately from wire to each final model.
The guard irons, bent and filed up from nickel silver strip are not the correct final version, but do serve to demonstrate that fitting is possible, even with the large flanges of the currently incorrect bogie wheels taking up vital space.

The next challenge is to sort out all of the filling and smoothing of minor defects and then add as many rivets as I can manage...