Atlantic's works: Portable layout - Scenic details next

[S.A.C. Martin]

She's alive!

Graeme, stunning conversion. It goes round second radius curves eh? That puts a damper on the "won't go round trainset curves" argument against the A2/3s.

[Atlantic 3279]

Hopefully Bachmann will bring one out next year

Hopefully not! I must get you a larger stirring implement Mick.

Lots still to adjust and tidy up Simon, but glad you both like it so far. Perhaps a proper trial running period with tender and train will feature shortly. It looks like my packet from Comet may already be here in this morning's post too. 24 hours dead after ordering - now that's not bad service .

[mick b]

Hopefully Bachmann will bring one out next year

Hopefully not! I must get you a larger stirring implement Mick.






Whats the problem with a Bachmann version Surely you not making that many conversions

[Atlantic 3279]

Good question. Probably not, but the chance to produce a few on commission first might be nice.

[Atlantic 3279]

Running trial results favourable. Ten coaches (5 Lima Mk1 and 5 Phoenix/BSL aluminium Gresleys) hauled without any suggestion of wheelslip. Lengthened chassis behaved itself on my 3 foor radius curves at any rate, save for leading bogie wheels frequently binding in the frame cut-outs as the loco straightens out of a curve. I think the leading cut-outs may need a touch more depth, but it is quite evident at the moment that I firstly need to address the problem that my frame cut-outs are centred further forward than the bogie wheels. I believe the cut-outs are as nearly right as possible, and depending on which point I choose as datum, both the bogie and the cylinders may deserve moving forward by 1 to 1.5mm, which would centre the wheels nicely in the cut-outs. The reason for conflict between measurements taken from different datum points is not in this instance MY inaccurate modelling - it stems from the stretched 27mm + 27mm wheelbase of the Bachmann loco (which should be 26+26) and its perhaps slightly undersize cylinders.

Looking at the amount of bogie side swing on my curves, I'm even more certain now that the fitting of front steps will not be a practical proposition for service on tighter curves - I may only just get away with them on my 3 foot radii.

[davidwest]

Astonishing!!!!

[S.A.C. Martin]

Looking terrific Graeme, as is the PM you sent me previously. I am looking forward to slapping some British Railways Dark Green on her...

[mick b]

BR Green APPALING waste of a beautiful Loco

[S.A.C. Martin]

BR Green APPALING waste of a beautiful Loco

You mean BR Green AND conversion to a Thompson, surely

I personally love that combination. Can't wait - never owned a (working) Thompson pacific before, it'll fit right in alongside the A1s and A4s

[mick b]

No just the colour


nowt wrong with a nice A2 or any Thompson Loco either

[Atlantic 3279]

Adapted Comet V2 motion bracket now fitted and shortened Comet V2 con-rod one side too. If the rest of life's problems can stay out of my face today (fat chance going by yesterday's pattern.....) I might have a full set of valve gear on both sides later....

[S.A.C. Martin]

looking forward to it. It's quite a transformation to watch, I suppose technically a "backdating" but all the same, very impressive and I am sure it looks easier than it actually is to do.

[Atlantic 3279]

Victory! Two sets of working "Bachmann-Comet Cross" valve gear, albeit mainly employing the most "simplified" version of the Comet layout - but what a struggle to sort it out first time around, not helped by the total lack of common ground between Bachmann valve gear technology and after-market standards
I'm too exhausted to sort out a picture tonight. Maybe tomorrow?

[52D]

Looking forward to seeing the results.

[Atlantic 3279]

As seen in these images, the cylinders are not yet consistently sitting at the correct 1 in 30 inclination, because although the stretcher is the right shape it is not at present screwed down and the fit of the front end of the body requires refinement - it is currently pressing down on the leading edge of the stretcher and tending to undo the inclination of the cylinders.....
But anyway, here's the valve gear. I still need to put a spacer behind the expansion link to finally remove any risk of the eccentric rod wafting inwards and coming into conflict with the con-rod. I also need to put a new thin back layer on the slidebars to keep the crosshead firmly in its slot. However, it does all work.
I've had to split the motion bracket stretcher into right and left halves and insulated it from chassis and running plate, as Bachmann's wheels and valvegear are live, only the axles being neutral. Much time was spent fathomimg out which rods I could use, big holes being needed for Bachmann's crankpins (mercifully Comet's big ends had enough meat in them to take the holes, as Bachmann's con-rods are cast and cannot readily be shortened) and the integrally cast pins on the back of Bachmann's crossheads (which I was keen to save) being next to impossible to preserve undamaged for re-use. But I managed to "fiddle it". Please note also that after some ultra-careful sawing of new notches in the end of the cast-in crankpin, my left side return crank now leans the right way, unlike the ex-factory offering.