Atlantic's works: Portable layout update

[Danby Wiske]

Just make sure your timetable has the same number of Up and Down trains...

[Atlantic 3279]

Or only watch equal numbers of ups and downs?

[Chas Levin]

Sounds like one of those warnings in speeded up speech at the end of financial services adverts: "Please be aware that the direction of your trains can go Up as well as Down"

[Danby Wiske]

Or only watch equal numbers of ups and downs?

Yes, that's what I had in mind.

Sounds like one of those warnings in speeded up speech at the end of financial services adverts: "Please be aware that the direction of your trains can go Up as well as Down"

And in both contexts, if too many go down, you're screwed...

[Atlantic 3279]

A brief reversion to the matter of rolling stock:

Almost four years ago I showed the completion of some Bill Bedford Mousa Models 3D printed kits for GNR six wheeled carriages. At that time, I felt that the outer corners of the lower stepboards would be vulnerable to knocks, so I bolstered the outermost printed hangers using some pieces of 0.9 mm stiff brass wire, bent to L shapes, inserted into holes in the floor, and firmly superglued to the floor, the printed hangers and to the undersides of the stepboards. Those have been fine, but I've had trouble in the middle of the underframe of one vehicle where I thought all would be well...

The middle wheelset of my dia 245 full-third developed a recurrent habit of falling out, along (later) with the sprung carriers for the bearings. Having simply put it back in and given the W-irons a gentle remedial squeeze on a couple of occasions, the next time it happened there was a nasty cracking sound as I squeezed the W-irons, after which the W-iron on one side went rather limp! Examination showed that all of the uprights of the W-iron, and some of the adjoining hangers for the lower stepboard, all part of the same structure, had broken away from the solebar. I put it quietly aside while dealing with layout construction and considering the best way to repair the carriage...

I thought about just bolstering the accessible J-hangers with some more 0.9mm brass wire stuck to the inner faces, but wondered how effective and lasting that "repair" might be. I eventually decided that I would try a complete alternative to Bill's centre suspension, in the form of a brass tube around the axle, the tube soldered to some springy wires suspended from the floor towards one end of the vehicle. Having checked, and found that my brass tube could be no more than 11mm long without the risk of restricting the sideplay on that axle, I realised that the springy wires would have to stay within that width in the area between the wheel-backs too. I was concerned to ensure that I ended up with the downforce from the springs spread well over the full width of the wheelset, as I didn't want the wheelset to tilt when traversing a curve, and I wondered if the maximum of 11 mm would be enough spread of that downforce. I never did find out, as when I started trying to accommodate the springy wires, as discreetly as possible, I ran out of patience and confidence in the probable result, on account of having gas tanks in the way to one side of the axle, and vac cylinder plus brake hangers in the way at the other side! You can see in one image below the holes I had initially drilled in the floor left of the gas tanks, ready to insert the ends of my springy wires, but I would have had to form the wires so as to pass around the outside edges of those tanks and then immediately "double-bend" inwards to pass between the wheel backs even when the wheels were fully off-set to one side.

I then decided that it would be better to try to make Bill's suspension arrangement work again, keeping the weight on the ends of the axle. I have bolstered the J-hangers with stubs of brass wire, as I originally considered, super-gluing the stubs in place as well as gluing all of the fractures in the W-iron. In addition, to resist future splaying of the W-irons, I've drilled into the nearby parts of the lower stepboards and hooked in the upturned ends of some 0.45mm brass wire tie-rods, also glued so that they don't fall out. For further prevention of the possible total loss of the wheelset and bearing carriers, I've added some wire safety loops, glued into holes in the floor.

What will now defeat my scheme? 3D prints not ideal for delicate underframes???

[Chas Levin]

What will now defeat my scheme? 3D prints not ideal for delicate underframes???

I would have to agree with that. Careful handling is all very well, but even the most vigilant operator will occasionally fumble with something and grip a delicate part a little too strongly.
Great material for larger, heavier structures of course, so mixed media kits seem to be the best compromise, IMHO.

[jwealleans]

I've used a couple of Bill's 3D printed 6 wheelers on Grantham over several shows with (thus far) no disasters.

I also use a couple of his 3D printed bogie Howldens, but in those cases I replaced the bogies with brass ones so I could solder in Kadee coupling holders.

I have had a complete catastrophe with one I don't take out to shows, which was dropped and on which the underframe has shattered along one side. Once Bill is able to he has said he'll supply a replacement as otherwise it will need to be completely rebuilt.

I also use Bill's recommended method for fitting the centre axle on these, but on most other 6 wheelers I've ever built I simply put a piece of tube on the end of some wire to hold the axle and allow it to dangle. All the carriages in the 1938 train on Grantham are done like that and they don't give any problems with derailing or riding up. 0.45 wire is floppy enough to go where it's pushed, but springy enough to exert enough downforce to keep wheelsets where they ought to be.

[Atlantic 3279]

In light of that information, if I do have further trouble with the repaired centre suspension, I’ll consider reversion to the 11mm brass tube idea with only a single, central, springy wire, as it now occurs to me that I could easily make and add some guides to limit the upward and downward movement of each end of the axle, ensuring that it cannot tilt excessively on curve. Maybe I should worry less about the details, even if past experiences of axles on spring wires haven’t always been trouble-free. There’s probably not enough room under the floor for the flanged wheelset to tilt a great deal anyway...

[Mercator II]

Today I had the privilege of visiting Grimsby (not what you hear very often!!) on an invite to see the progress of Graeme's portable layout

I have to say that the layout is far better in the flesh so to speak, than on a screen, and with no trains yet running, will only increase at Mr K continues

I was also invited to play on his permanent layout ans see where the portable fits in on that

We got to run a few of his excellent creations around before other commitments pulled me away

Thank you Graeme for the invite and brew, and I look forward to seeing the progress in readiness for the show next year

[Atlantic 3279]

Thanks for the glowing review Brian!

[Atlantic 3279]

Just a quick reminder:

Visitors expected from as far afield as South Australia...