4mm Dave's SR Loco Workbench - Adams A12 Jubilee

[dltaylor]

Chassis has now been chemically blackened and sprayed matt black.
Two strips of copperclad fibreglass sleeper strip have been Araldited to the frames, and "backscratcher" pickups fitted made from phos-bronze strip. The trick with phosphor-bronze is to not put sharp bends in it, it breaks very easily. So the strip was curved around a 1.6mm rod before soldering in place. It will accept quite a bit of tweaking to get the bend right though. Also the business end had a double curve put in it so that the face of the strip rubs the wheel and not the cut end.
The Gibson wheels are blackened and ready for fitting.





Thats all for now,
Dave.

 

[AJC]

Nice job Dave and the approach to the pick-ups is interesting. I've done much the same thing before but with Phosphor Bronze wire rather than strip; the prototype would have been one with rather smaller wheels so there wasn't the space. I have a bitsa Standard 4 to finish at some point (Mainline body, early Comet chassis, shelf queen status down to the Hornby and Bachmann versions appearing) and this will be an ideal opportunity to revisit this approach.

I look forward to seeing the body go on.

Adam

 

[dltaylor]

Well, it works!

My trusty GW Models wheelpress got everything assembled, and after a bit of tweaking of the pickups and some lubrication, it ran very satisfactorily.
Alan Gibson had run out of 8-foot coupling rods, so these were assembled from his universal coupling rod kit. Drilling them out to 1.6mm to take the bushes, the drill snatched and broke the end off one rod at a weak joint. Fortunately there was enough left on the kit etch to repair it, and I drilled the rest by hand.





Thats all for now,
Dave.

 

[dltaylor]

I've filled in the bottom of the boiler where its visible between the splashers. It was done with a bit of curved brass and some trial-and-error bending. Once it was about the right shape and would stay put, I soldered it in.
To keep the driving wheels firmly in contact I filled the front half of the boiler with a lump of lead.



Again, with a view to keeping the drivers on the rails, I've added a touch of springing to the carrying wheels. By slotting the axle holes they can move up and down a touch, and springy wire acting on the treads keeps the wheels in contact AND provides pickup.
How well this will work in practice I know not, time will tell. As I'm planning pickups on the tender, pickup on these wheels may not be necessary, so I can simplify the arrangement.



Putting it all together







I'm now thinking that the cast boiler bands look a bit hefty, I might file them off and replace them with lining transfers.

Cheers, Dave

 

[dltaylor]

Time for another of my occasional updates on this loco, I've been working on the tender at last.
Body all soldered together very nicely, nothing to comment on there. Whitemetal coal-rails often take a bit of a bashing, and this is no different. I will leave these till last to sort out though, might even replace them with brass.

Inner chassis is a bit different though. As per normal the axles run in whitemetal slots with retainers. I wanted tender pickups, so this time a large pickup plate was fixed atop the chassis. Pickup wires (15thou NS) bear on the tops of the treads, giving a touch of downward force to the wheels to keep them on the rail and picking up. The bits of brass sheet are raising the tender body to its correct height relative to the loco.

To keep the wheels removeable I've fitted longitudinal retaining wires, screwed in place, instead of gluing on the whitemetal retaining plates. The 10ba securing nuts are a bit prominent, so I might change them.


Tender drawbar is my usual piece of copperclad fibreglass pcb, gapped for current conduction. Need to install a plug & socket connection and some wiring, then see how it works.


Thats it for now,
Cheers, Dave.

 

[dltaylor]

After a VERY long layoff, I've managed to get back to the Jubilee and make some progress. Body detailing such as handrails, boiler fittings, reversing rod, sandbox rods etc are appearing.
I filed the rather massive boiler bands away and used some pressfix lining to represent them, covering them with a coat of primer.
So at least its starting to look like a loco now.





Tender toolboxes were missing from the kit when I acquired it, and I drew a blank trying to find some cast replacements. (Adams tenders were quite different from the later Drummond versions), so I ended up making my own. They were filed to shape from 1/4inch square brass rod, with lids & hinges soldered in place. They won't be dimensionally accurate, but at least they look the part.


That should get things moving again.
Cheers, Dave.

 

[Adrian B.Swain]

Hi All Nice to see a Jubilee under construction. Many moons ago I cast these for Bill Stott and in fact largely rebuilt and upgraded the original patterns. I still have the No 1 set of castings made up in black with Bullied lettering and to EM standards. The model was basically accurate but lacked many of todays refinements especially the chassis and cab interior but was quite good for it's time. I still produce the tender as a kit for a water supply tank and other redundant tenders were used in one of the weedkilling trains, I see the water filler is missing and I have a few left. A few stamps will secure one and other tender bits which may be missing. Don't forget to remove the small air bleeds between the coal rails just before you paint the loco. It is also a good idea to pile up coal against them to stop them being distorted as they are pretty fragile.
They should really have been etched but the rods had already been produced so a new sheet was not financially viable.
I have predated my SR interest so the loco really needs a visit to the paintshop for Maunsell livery and a general clean up. I had a Kernow O2 on order but having seen how innaccurate the mainland version seems to be in the 2nd EP pictures I guess its back to the etched kit again. At least I should be able to get the back end nearly correct using the kit, I don't fancy a major rebuild and a repaint having spent that much already. Perhaps the Radial from Oxfordrail will prove better if they do it in Maunsell green.
Best wishes for the project Adrian

 

[Adrian B.Swain]

Hi All I like Dave's copper clad tender coupling but I wonder if he could have dispensed with the plug-in flying leads by making a "2 pole Commutator" out of the peg and soldering thin N/S springy wire to the copper clad to connect both sides of the commutator thereby eliminating the leads altogether. It is then possible to disconnect the tender without any fiddling about. I have used concentric metal pins insulated from each other by sleeving as well but have never been able to find a small enough commercial 2 way jack plug that lends itself to this purpose. Tender pickup is a great advantage but I just hate the plugs and sockets, so often the wires break because they need to be fairly thin and flexible. Any other suggestions?? Adrian