Atlantic's works: Portable layout - Scenic details next

[Atlantic 3279]

Thanks Simon. Do you still want some resin parts by the way?

I met with Morgan at the weekend and after some scrutiny of the built up test etches we have agreed on a number of improvements to further samples. These changes will probably include:
1. Radius rod slightly shortened on A2 gear
2. Integral valve rod extension pieces on all radius rods - use if it makes your chosen fitting method easier, cut off if not wanted
2. Bigger big end hole sizes on A2 con-rods. CORRECTION, I MEAN A1/1. Thanks Morgan....
3. Motion bracket height (or depth below running plate) increased on A1/1 to ensure a closer fit to the slidebars
4. Correct clearance for leading coupled wheel flanges and correct location of the brake arms/shoes themselves on new A1/1 front brake unit
5. Minor tweaks to handrail holes on A2/1 and A2/3 smoke deflectors
6. Optional parts for multi-layer expansion links and forked rear ends of radius rod (huge cheer now expected from P4-o-philes and other afficionados of ultra-detail). Fit them all in if you can - enjoy slimmimg the layers down for clearance if necessary!

Following those discussions, I've also made a better job of fitting the trial brake unit to Great Northern (pictures and notes later) and I hope this evening to tackle the completion of fitting of the new trial set of valve gear to Steady Aim.

[Horsetan]

Thanks Simon. Do you still want some resin parts by the way?

.....6. Optional parts for multi-layer expansion links and forked rear ends of radius rod (huge cheer now expected from P4-o-philes and other afficionados of ultra-detail). Fit them all in if you can - enjoy slimmimg the layers down for clearance if necessary!.

*loud cheer*

And the links, being an ostensibly standard part, should be useful for other LNER Pacifics, etc.

[45609]

.....Bigger big end hole sizes on A2 con-rods....

Wasn't it the A1/1 con rod big ends?

[Atlantic 3279]

I'm glad you're payiing attention, as I obviously wasn't. Yes, A1/1 con rod holes. Correction duly added to preceding post......

SINCE THESE NOTES WERE ORIGINALLY PRODUCED, A SEPARATE AND FULLY COMPREHENSIVE SET OF ILLUSTRATED INSTRUCTIONS HAS BEEN PREPARED AND IS AVAILABLE FROM ME BY E-MAIL. IN ORDER TO USE SPACE TO BEST EFFECT THE IMAGES ORIGINALLY DISPLAYED HERE (AND LATER LOST DUE TO DISCONTINUATION OF REMOTE-HOSTING SERVICES) HAVE NOT BEEN REINSTATED.

Okay, pictures of the A2/3 custom valve gear fitted up to the loco, to prove that it does all fit and work. I started by revising my initial arrangement of the radius rods relative to the pivot pins in the motion bracket, looping the slot in the rear end of the radius rod over the central pivot pin for the expansion link as well as the pin in the nose of the lifting lever. This moved the rod aft a little to give the correct position for the joint to the combinationlever at the front of the radius rod. The loss of vertical freedom of position for that joint has not been a problem at all, everything lines up satisfactorily. In one of these images the motion bracket stretcher isn't quite tight up against the base of the running plate, as it should be. I have since re-packed it so that it fits snug.



There's a slight quirk when it comes to connecting the new eccentric rod to original Bachmann return crank, which (latter) part will not solder. Fortunately, it is a thick crank and the hole in it is a smaller diameter at the outer face than it is at the inner face. The brass pivot pin can thus go in, from the outside face as normal, then a plug of solder can be deposited on that pin, filling the slightly over-size hole in the crank, locking the pin in place. The inner face can then be trimmed smooth so that nothing catches on the con-rod during rotation. It now looks as if TWO only of the spacing-out washers for the big-end are actually needed each side. I also established, by unsuccessful trial, that you CANNOT dodge the problem of how to solder the return crank joint joint by putting the pin through from the inside face and soldering it to the eccentric rod on the outside face instead. Sooner or late, that head on the inside WILL jam up against the edge of the con-rod. You have been warned....

For this motion bracket stretcher, I have employed the stronger and frankly better method, preferred by Tim Easter and Tom Foster, for producing the necessary insulated mounting - although it calls for a little more effort than my other method of just gluing the stretcher onto plastic and then gapping it. I've soldered two strips of PCB sleeper to the underside, bevelling their edges so that the copper doesn't touch the chassis block at its edges. I've then double-gapped the stretcher itself and the copper layer at the etched dotted lines. I avoided the option of the single central gap, as the screw hole weakens that area anyway. An additional sub-layer of approx 30 thou plastic brings the stretcher up to the correct height on the chassis.

[mick b]

Very nice looks much easier then modifying the Bachmann / Comet gear .

[Atlantic 3279]

And here's a "proper" way (followed by a simpler one that's almost as good) to deal with the mounting of the new front brake unit for the A1/1, which caused me some difficulty at the first attempt last week.
If the inner, or top, or "true" keeper plate on your A3/A4 chassis won't descend fully because the wire that goes up to the motor won't pull down through the hole, then short of cutting the wire and then re-joining it afterwards, your only option is to release the motor to un-trap the wire. To do this, you have to undo the screw in the top of the gear cover in front of the motor (it has a wiring tag attached to it) to release the gear cover which also holds down the front of the motor. You may also have to unscrew the tall wedge-shaped bracket at the rear of the motor, the screw-head for which is under the chassis. The motor can then be pulled free of its blob of black goo that also holds it to the chassis. THEN you can free off the wire that goes through the hole in the chassis under the motor. Why do they make it so difficult? Once the gear cover is off, all the gears fall out when you turn the chassis over, if you don''t watch out. At least they are easy to put back in!
Now the keeper plate will come well away from the chassis and you can get a proper look at its top side. Notice how all the wheelsets then want to fall out too, and the bearings shuffle along the axles making it awkward to jiggle them back into the chassis properly? Fun isn't it? NOT!

Anyway, once you are able to see the top front of the keeper plate you can pop the new brake unit onto it and it looks something like this:

It is clearly designed to fit but thefront of it will not sit in place properly because there's a raised lip all round the well in the front of the plate. That lip needs to be carved off across the front of the plate, including the corners, with care, to produce this:


You can then insulate the top of the brake plate with tape or a layer of plastic to keep the brakes electrically separate from the chassis, and glue or screw the brake unit to the plastic keeper plate. You can even split it down the middle to make double-sure electrically.
Here's one I've modified, anticipating the changes that Morgan is including on thje etches, so as to ensure front flange clearrnces and proper positions for the brake shoes (with rigging easy to re-fit without strain)

The leading edge of the mounting plate, with its crescent cut-out, JUST shows over the matching front edge of the keeper plate:

The flanges have clearance:

And the rigging fits with no forced bending of the yokes as previously.


SINCE THESE NOTES WERE ORIGINALLY PRODUCED, A SEPARATE AND FULLY COMPREHENSIVE SET OF ILLUSTRATED INSTRUCTIONS HAS BEEN PREPARED AND IS AVAILABLE FROM ME BY E-MAIL. IN ORDER TO USE SPACE TO BEST EFFECT THE IMAGES ORIGINALLY DISPLAYED HERE (AND LATER LOST DUE TO DISCONTINUATION OF REMOTE-HOSTING SERVICES) HAVE NOT BEEN REINSTATED.

[Atlantic 3279]

SINCE THESE NOTES WERE ORIGINALLY PRODUCED, A SEPARATE AND FULLY COMPREHENSIVE SET OF ILLUSTRATED INSTRUCTIONS HAS BEEN PREPARED AND IS AVAILABLE FROM ME BY E-MAIL. IN ORDER TO USE SPACE TO BEST EFFECT THE IMAGES ORIGINALLY DISPLAYED HERE (AND LATER LOST DUE TO DISCONTINUATION OF REMOTE-HOSTING SERVICES) HAVE NOT BEEN REINSTATED.

Of course, in order to save releasing the motor and then having a struggle with loose gears and wheelsets, it occurred to me that if you don't mind a height error of 1mm or less in the position of the front brake shoes, it would be a lot easier to procced as follows:

1. Stick a layer of thin tape to the top face of the brake mounting plate for electrical insulation.
2. Firmly glue a rectangle of 30 or 40 thou plastic to its lower face too, arranging it to be the full width of the plate. The rear edge of the plastic should align with the apex of the crescent in the rear of the metal plate, but the front edge of the plastic should be say 1mm behind the apex of the crescent at the front edge.

You can still split the plate down the middle as part of this process if you wish.
3. Now just release the front of the keeper plate sufficiently to slide in the brake mounting plate above the keeper. The shallow plastic block on its lower face will key the brake unit into position in the well at the front of the keeper plate when the keeper plate is screwed back firmly in place.

Very nice looks much easier then modifying the Bachmann / Comet gear .

Hi Mick - yes, simplicity is certainly the goal.

[45609]

To complement Graeme's photo essay on how to fit the front brake hangers here is an exploded 3-D diagram of the revised design. The length of the plate has been increased by 0.5mm to eliminate the need to slip in the pieces of plasticard. The diagram also shows that it was a design intent for the builder to put a length of wire through the top pivot hole. The ideal size wire is 0.6mm but this will need a flat filing on the underside to slide in through the pivot hole horizontally. This not only will strengthen the assembly but will also give a bit of necessary detail to replicate the hanger pivot pin. The other thing to note about the front brake hanger is that if you wish to split the hanger, either for insulation or widening for application in EM or P4 , the square array of four holes can be used to drill into the plastic keeper plate and fit locating pins.

[Atlantic 3279]

With the test builds of the pacific valve gear etches largely sorted out now (although I still have lots of construction guidance notes to write or re-write, as simply as I can, and organise into proper sequences) I turned back to the tedium of adding riveted strips to the GC 40 ton bogie coal wagon last night. Quite a lot of it was done by the time I could face no more a little after 10pm! There are now certain irregularities in the masses of hand embossed rivet lines, as the production of the strips is time consuming and I couldn't face discarding all but the very best ones. I suspect the finish on the wagon will probably therefore be more of a "looks good on a layout" standard than a "fit for display case and magnifying glass" one. Time will tell.

[S.A.C. Martin]

Thanks Simon. Do you still want some resin parts by the way?

Yes definitely - see emails!

Just looking over the photographs - exquisite work, well done Morgan and Graeme.

[Coronach]

I don't know what we'd do without your Talents Graeme. I'll definitely be having these etches for my own A2/3 conversion. In fact I'll do a second one as well now!

Dave.

[Atlantic 3279]

Thanks Gents - all comments most welcome and duly noted. I may be quiet for a few days now. Don't worry, I'm neither sulking nor ill, but we're about to try to have a "long family weekend" here - hence the inevitable atrocious weather. I should be back to my usual antics by the middle of next week.

[Dave]

Enjoy your break, come back refreshed and be ready to do some more amazing stuff.

[Blink Bonny]

Ay up!

Watch out for brick walls, Graeme and I hope you have a good time.

[Horsetan]

.....we're about to try to have a "long family weekend" here .....

If it involves other relatives, it can feel very long indeed