Atlantic's works: Portable layout - Scenic details next

[Horsetan]

Yep, placcy spokes......

Aha - now how easy would it be to remove the plastic centres? The reason why I ask this is because Hornby do a visually-correct BFB driving wheel on their SR "Q1", which includes the domed appearance. They are the only ones apart from Markits to achieve this, but Markits don't cater for P4.

If it proves possible to remove the centres, then I could re-use them with Gibson P4 profile tyres and axles.....

[Atlantic 3279]

I've not yet found a loose Hornby tyre nor deliberately tried to remove one, but as the wheelsets are available as spares quite inexpensively from EKM you could experiment at low risk. What are the chances however of finding exactly matching inside diameters for the tyres? If the plastic centre is a bit big you could skim some off to get a good fit I suppose, but could you get the centration right by packing if the fit is sloppy......

I don't suppose it would matter if the Hornby wheel centre is meant to suit a wider tyre, I guess you just fit the tyre flush to the outer face and forget what hangs out at the rear.

[Horsetan]

I've not yet found a loose Hornby tyre nor deliberately tried to remove one, but as the wheelsets are available as spares quite inexpensively from EKM you could experiment at low risk. What are the chances however of finding exactly matching inside diameters for the tyres? If the plastic centre is a bit big you could skim some off to get a good fit I suppose, but could you get the centration right by packing if the fit is sloppy......

I have plenty of Loctite 603 in case anything goes tits-up.....

I don't suppose it would matter if the Hornby wheel centre is meant to suit a wider tyre, I guess you just fit the tyre flush to the outer face and forget what hangs out at the rear.

The back of the wheel centre would probably need thinning down anyway, as I would want to use them on an etched chassis built to P4 width...

[2002EarlMarischal]

Warley is bit too far (two and half hours absolute minimum from here), a lot too expensive and a bit too daunting (by virtue of being at the NEC hell-hole). Minimum tenner a day to get in, then another fleecing of at least £8 for parking (unless you park remotely and shuttle by train), then hours of trudging around in "dead" air, on unforgiving concrete floors until your ankles cry out for relief - with nostrils frequently assaulted by the fried onion/cheeseburger merchants and those delightful adherents to our hobby who constantly dodge the soap, never change clothes, and have the dental hygiene of a dead crocodile.......

Glad I'd eaten my lunch before reading your stunningly accurate guide to Warley! Once a year I can suffer most of those things but it's the rip-off car parking that really gets me!

[Horsetan]

...... nostrils frequently assaulted by .... those delightful adherents to our hobby who constantly dodge the soap, never change clothes, and have the dental hygiene of a dead crocodile.......

But you can find them at almost any exhibition.

I went to Warley once in 2001. I got there late because the Virgin Trains service calling at the NEC was delayed. It did cost quite a bit to get in. The sheer number of people attending was unbelievable, though - I shall forever have a memory of the Hornby display trailer which had so many visitors trying to get inside that people were hanging off it in the style of an Asian subcontinental commuter train.

[Daddyman]

You've just talked me out of Warley!
I was just thinking how nice it was to have a GW-free zone after RMWeb, and then you went and wrote that other thing you wrote!

[Atlantic 3279]

I promise faithfully not to mention "that other railway company" again in the near future, and never again unless I give fair warning so that those of a delicate disposition can turn their attention away .

I certainly agree that the walking cess-pits can be found at every exhibition, in fact Spalding can be quite good for over-ripe ones.

A1/1 catch-up follows shortly (quick, turn to another channel.....)

[Atlantic 3279]

I bonded the lower firebox extensions to the correctly positioned running plate extensions. Then followed a certain amount of filing, sanding, repeat filling and so on, plus the addition of a DMR etched oval cover and a strip of plastic to complete the cladding band. I then ran the razor saw down the throat plate, along the line of the inner edge of the running plate, and separated the add-on pieces from the original bodywork, as I had threatened.

Here's how the items looked when separated, so this shows the extent to which the firebox will neeed to be cut back if and when fitting a finished resin part. Note the installed plastic blocks, which allow me to currently temporarily screw, and ultimately glue, the add on pieces firmly in the right place. Here too, as you can also see, I've tidied up the back of the firebox extension piece to get it truly flat, matching the inboard edge of the running plate, and had a short session of rattle-can aerobics.

Fitted back on the loco, in close up:

The latest stand-off side view:

Or in perspective, now with the trimmed and recycled Hornby cylinder steam pipes back in place, at present lacking the sloping section of steam duct to their rear edges:

[S.A.C. Martin]

Just a thought Graeme - the outside steam pipe plus the extension would be better moulded as a separate piece, all in one, no? Other than that the modelling is exceptional and the way you've done the running plate is genius.

I've said this before of your A2/3, but these RTR conversions look a hell of a lot more convincing than most of the kits out there.

[Atlantic 3279]

I think you are right that the steam pipes ought to be separate, at least for mouding purposes as they have a sloping "inboard" face so cannot be moulded with their backs flat, in line with the rest of the inboard edge of the running plate. It might however be possible to include all of the sand-fillers, lubricators and oil boxes (plus the shallow lip) along the inboard edge of the running plate.
Separate steam pipes, added later, would also leave the immediate "theatre of operations" clear for aligning and blending the joint in the running plate, and you'd then still have the chance of hiding any residual error by planting the steam pipe hard against the joint.

[Bill Bedford]

Yep, placcy spokes......

Aha - now how easy would it be to remove the plastic centres? The reason why I ask this is because Hornby do a visually-correct BFB driving wheel on their SR "Q1", which includes the domed appearance. They are the only ones apart from Markits to achieve this, but Markits don't cater for P4.

There will be P4 Q1 wheels available after Christmas. -- watch this space.

[Atlantic 3279]

Turning back for a moment to the as yet still not quite finished Steady Aim, I'm trying out a replacement for the original Bachmann trailing axle springing/tilting/sliding mechanism. The latter does nothing to steer the flanges of the wheels around the curves, and in trial running I've had trouble at times on setting back through pointwork and crossovers with the flanges scraping at the inside edge of the outer rail and (of course) climbing over it at the first excuse or going the wrong way at crossings.
My trial arrangement involves nothing more elaborate than two lengths of spring wire, super-glued into drilled holes in the chassis, bent over rearwards, and soldered to the base of an axle bearing tube, thus:

As the wires are not bent fully to 90 degrees on leaving the holes in the chassis, they exert some downward spring pressure on the rear axle, helping the wheels to track. The wheels now also hang well below the loco when it is lifted, making it easy to get them properly on the track, which I always found difficult with the original arrangement. The "splay" of the wires ensures that the axle doesn't just move sideways on curves, it steers.

Trial running now shows that I can set the loco back through pointwork at ridiculous break-neck speed without derailment or even a twitch. My main reservation now is that the repeated twisting of the wires in the holes drilled in the chassis may eventually break them free of the super-glue that holds them in. More development may be needed.....

If this arrangement, or a development of it, proves durable, then the other advantage of course is that those raised metal lumps that were part of the original rear axle mounting, and which protrude above running plate level into the space under the cab around the base of the backhead will be redundant, can if necessary be sawn off. This makes the fitting of modified cabs and fireboxes a lot easier. It should even be possible to fit a body whose backhead and cab are a foot further forward than those of the A2, A2/2, A2/3 or A1 types. This aids the ideas I've been considering on the awkward A2/1 theme.

[S.A.C. Martin]

Very interesting mod there Graeme. Thinking on how it could be modified, perhaps a simple cap over the top of the wires, incorporating a channel either side to hold them in position, would suffice.

[Atlantic 3279]

Looking at things again this morning, I think it might have been quicker and easier to bond a piece of PCB in place with epoxy between the springs under the rear coupled wheels, and solder the leading end of the "A-frame" of springy wires to that PCB. That would avoid the slow tricky job of drilling those two deep 0.5mm dia. into that cast armour-plate block. The trailing wheel carrier would then be attached to the chasis keeper plate of course, but I don't see why that would be any problem.

[Atlantic 3279]

Going back to something I said a couple of pages ago, i.e.

while I was measuring up I noticed that other dimensions of the valve gear, such as the length of the eccentric rods as per the Isinglass drawing, don't match comet's version of the V2 valve gear that I am hoping to use. The Comet eccentric rods appear to be too short, so rather than "simply" fitting mainly standard Comet V2 valve gear it looks like I'll have to brew up another combination of Comet's parts and longer items (shortened) from the RTR model.

I've done some more measuring tonight, including some dimensions obtained from broadside official photos of actual locos, and if we keep everything in 4mm scale, this is what I reckon about eccentric rod lengths:

Comet "V2" etch = 18+ mm, say 18.2 by my best estimate.

Green Arrow V2, official photo = about 21mm (possibly 20.

Great Northern A1/1, official photo = about 21mm (possibly 21.4)

Great Northern, Isinglass drawing (not the same both sides!) = about 21mm

A2/1 official photo (development of V2 but with definitely shorter, more steeply inclined eccentric rod) = about 18mm (possibly 17..

So if I've done my measuring correctly, this could support the suggestion that Blink Bonny made to the effect thet Great Northern's valve gear used V2 parts, but Comet's interpretation of the V2 valve gear is well off target. I can see that by erring on the short side with the eccentric rod they may have sought to ensure that it would not foul the rear end of the slidebars on its forward stroke, no matter how inaccurately assembled, but it doesn't help those who have built accurately and who wish to see their expansion links oscillating through the correct angles. It won't do on my A1/1 either - 20mm would be acceptable according to my assessment, but not a mere 18mm.
Oddly enough, it looks as if the 18mm length would be near enough the correct scale one for an A2/1, A2/2 or A2/3. I believe that Tim E has managed to use the Comet eccentric rods on an A2/3 conversion that he has assembled, although I couldn't see how I could safely accommodate much more than 16mm on my modified Bachmann chassis. Were my slidebar ends too far to the rear I wonder, or does Bachmann's return crank create too much travel of the rod??


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