West End Workbench

[drmditch]

At the risk of lecturing my betters, and those with much more experience than myself, may I offer the following:

With leading wheels (or bogies) and trailing wheels one has to consider their effect on the horizontal rotation of the entire vehicle; not just in relation to the centre of rotation, but also to the centre of resistance to rotation.

Given the sloppy engineering standards of my models, and the usual admissions about track, track standards, curvature, and transition curvature (or lack of it), the two centres may differ in longitudinal location.

When working on my A8 (currently back in shops after an encounter with debris carelessly left on the line after an engineering possession), having solved the problems with clearances with the cylinders and leading bogie, and got it running nicely as a 4-6-0, the addition of rear carrying wheels, constructed as a pivoted truck had the most alarming effects. Derailments occurred not at the rear, but with the boogie, and even with the leading coupled wheels.

When running in reverse around the same curves the same problem did not occur. (Even with the engine 'the other way round'). Close examination did reveal that the resistance to rotation created by the carrying wheels was considerable and differed forwards and backwards.

Several solutions were attempted and abandoned. Springing the truck did not work for me. The eventual solution comprised of:
Mounting the wheelset in a tubular bearing with ample sideplay.
Moving the bearing position for the truck as far forward as possible
Weighting rather than springing the truck.
(Well, I have admitted my engineering is sloppy!)

My problems were exacerbated by the need for the couplings to be mounted on the bogie and the truck respectively.

I have encountered similar problems with simple 0-6-0s and the effect of the tender drawbar.

The A8, after much empirical problem solving, has settled down to be a useful engine although still a bit track sensitive and thus useful for testing tracklaying. I look forward, when I have grown up (!) to building a NER Atlantic.

Perhaps the rotational problems may be easier to solve with a 2-4-2, but perhaps the shorter coupled wheelbase might make it easier for a flange to climb a rail.

[jwealleans]

Well, that's all been very interesting and thank you. I still haven't ordered the carrying wheels, so we're not at the stage of being able to test anything yet, but at the moment I'm looking most seriously at either remaking the frames with Comet spacers, which are narrower than the Gibson ones so increasing sideplay all round, or (probably and) chopping through the frames behind the cab steps and making the rear wheels into a pony truck.

I may put the motor and gearbox together today so I know what the minimum width between frames can be.

[60526]

Jonathan, very interested in this, I have the same Gibson kit and may have gone down the same route. I started making it in OO but it's back in it's box at the moment to be made in EM. I always prefer the wheels to all be sitting on the track so this is being made as a 2-4-0 with a compensating beam between the front axle and the first driver and a gearbox off the second driver, all would have some side play. For the rear the chassis was cut from behind the second driver horizontal to the back, a rear pony truck was then going to be made, I'd done a dry run with all wheels assembled, the minimum radii I was looking for was 2'-0" but it clearly was not going to work hence the move to a separate pony truck. Ironically in EM I expect the minimum radius to be 3'-0" so perhaps didn't need to cut the chassis anyway, but I still have the etch parts, but this sliding tube idea looks interesting. What I also considered was to make the Gibson chassis as a 2-4-0, yes the spacers are wider but didn't want any problems with mounting any gearbox or motor, the plan was then to cut the chassis vertically after the second driver and to scratch the rearchassis to the same profile as in the kit but to make it longer and solder it onto the inside of the front chassis so the rear wheels would have plenty of side play. I was at the time also playing with a Stephen Poole F4/5 which has a longer wheelbase and I think the idea came more from that model, these are the first 2-4-2's I've ever attempted and bring up a few more questions than normal.

[UpDistant]

OK, I stuck my head above the parapet when I suggested the London Road Models radial axlebox might be a solution to the problem as it is available separately rather than being part of a kit. It can be applied to any build not just LRM kits.

The problem - as designed, what you have with your F6 is a 2-4-2 with a relatively long wheelbase rigid chassis which will not go around any curves - no amount of side play will make the situation any better. The outer axles will always be parallel to the driving axles and, as the curve tightens, the angle of the outer axles moves from being at right angles to the rails when on straight track to a situation where the wheels are scrubbing around the curve.

The solution - introducing some flexibility is essential - JW has already alluded to this when he mentioned picking up his piercing saw. In its simplest form and taking Atlantic's approach, the wheelset is carried in a 2mm i.d. tube. The frames then require a slot cut into the bottom (of the frames), probably about 2-3x the outside diameter of the tube (start at 2x - you can't put the material back) - think of it as a narrower version of the normal hornguide cut-out, although the width of the cut-out might have to increase for sharper curves. A measure of control can be provided by soldering a stiff-ish piece of phosphor bronze wire to the top of the centre of the tube, the other end to the horizontal part of a frame spacer - downward pressure to keep the wheels on the track, centering control and also the ability of the axle to rock.

The radial axlebox approach is similar - it's just the slot has to be wide enough to accommodate the box and for the box to slide sideways in the slot. By using standard 2mm axle bearings there is less friction compared to a tube bearing. The same "control" arrangement can be applied. Whether or not you go down the route of having frame joggles as well is another decision to make - some prototypes have them.

Peter Stanger's (52F Models) C15, C16, N8, N10, and N15 chassis all have radial axle boxes - have a look the photos on his website. The difference is that they are weight bearing as well.

I wish I could draw, it would make it so much easier to explain. I've never been able to draw, and I don't think I ever will!

[mick b]

I did have a secondhand Bachmann LMS 2-4-2 chassis,now sold on as it had the wrong wheelbase for the F8.

All Bachmann have done is a "axle holder" moulding allowing a very small pivot inside the frames ,which has a vertical fixed spring pushing down on the axle at the same time. I never thought to try on the track to see if it actually worked before selling on.

[Chas Levin]

GN Implement wagon, main part of the floor replaced, just the infill parts between the ramps to add. Brake lever cut down from the Wizard Models parts. The single bolster has also had a brake lever added.

Hello Jonathan, apologies for posting out of sequence but looking at the pics you posted a couple of weeks ago, I'm just making one of those D&S Implement wagons myself & a little puzzled as to how the 'infill parts of the floor between the ramps' actually sit (no guidance in instructions and I haven't yet located a photo from above). Do you have any advice please?
Chas

[jwealleans]

Chas, apologies, I read your post and forgot about it. I'll dig the wagon out later.

Spent a large part of today adapting the F6 frames. We had a rethink on the pony and ended up putting it on the front. Two reasons for that - firstly, the front steps are larger and will cover it up more effectively but secondly, when all the wheels were fitted, they didn't all touch the track. I suspect one of the holes must be slightly off (these are rigid frames, which only have holes for bearings, unlike the usual Gibsons which come with hornblock slots already cut out). It was the front axle which was elevated, so it seemed logical to put that into a pony truck to allow vertical as well as lateral movement.









I made the pony truck up with Comet frame spaces as they're narrower than the Gibson ones, so the axles have some sideplay as well as the rotation of the truck to help them round curves. You'll see that I put an elongated spacer on the front of the frames to use the original fixing point (the gearbox prevents anything further back) and took about a mm off the tip of the front frames so they swing underneath it. It goes round my 2' 9" test track quite happily, so I think we may have cracked it. I also made up, fitted and fettled the rods, so it's been a good day.

In between that I finished off or worked on some more wagons, still all for Wickham Market. The last two opens I'd weathered now have crate loads:



There isn't the need for a full train of ferry wagons on this layout, but you have to have one (it's the Law). This is the one.



I can't remember the name of the place the load came from. It was in France and someone on RMWeb put me on to them so I gave them a try. It was bloomin' expensive, but it's very well done and fits the wagon nicely.

I'm going to get some more containers done at some point and this came from the second hand stand at Wakefield last November. It was Bachmann 37-930B, a B type container in a Medfit. I dug it out last week to repaint the container and when I looked at the wagon I found that it was numbered for a batch which were unfitted. It has Morton 4 shoe brakes, so I just pulled the vac cylinder off and repainted it grey. It'll have a lump of foam and a sheet on top when done.

[jwealleans]

Bit of weathering while I felt like it this evening as well. Since Thurston last went out I've built about half a dozen carriages which we can use on Wickham Market and they need weathering to match the rest. These were across the bench in the early part of 2017, I think.



D 244 Lav Compo. These are Bill Bedford sides on MJT everything else.



Comet D 62 Brake Third.

Some NPCCS as well:



ex-NER D 171 Milk van. We have a photo of one of these up the Framlingham Branch, so this will be used on that part of the layout. Hence the S & W couplings.



D & S D 87 Milk Van. Bit of a rescue job this one, hence the less than perfect grilles. I have a D 86 almost ready as well. You really can't run a GE Area layout without at least one of these kicking about.

[Chas Levin]

Chas, apologies, I read your post and forgot about it. I'll dig the wagon out later.

Thanks Jonathan, much appreciated. I had a look in Tatlow's LNER Wagons (single volume version) but the 10T Implement Wagon (Plate 204) is shown at eye level so you can't see the floor ends and the 6 wheel version (Plate 205) isn't much different in viewing angle. I don't quite understand whether the central floor ends go below that circular construction inside the headstocks, or whether the floor splits and goes either side of it? And if underneath, is that done by a slope or stepped? (And while we're on the subject, what is the function of that large circular construction on the inside of the headstocks?)
Very nice little wagon don't you think? Do you plan on adding a load? I'm thinking perhaps a tractor...
Very nice Eastern region carriages - I particularly like the NER D171 Milk Van with the rounded inner panel corners. I've been immersed in GNR for a while so they look very different to me
Chas

[jwealleans]

Chas - I forgot about you completely. I'll go upstairs and dig it out as soon as this is posted.

More wagons rolling off the bench - I've had a rotten cold which I can't shake off and haven't done anywhere near as much as I'd have liked. Still, you do what you can and the rest can wait.



Bachmann 3 planker now weathered and sheeted.



Pair of Oxford POs. Not much done to these, really, just couplings and paint. Loads are in preparation.





Parkside Trestle. Not a wagon I'd have built, but it came to me assembled in a job lot so it's had some detailing and a repaint. It's not turned out too badly. Photographs of the prototype are not easy to come by, unless I just own all the wrong books.



ABS Twin Case. I finished this one in late LNER livery per a photograph in Tatlow 4B. Again, a vehicle I came by already assembled and it's just been refinished and detailed a little.



A couple on the way - Dave of this parish very generously gave me a Hornby brake van when I visited him, so that's been assaulted with the paint brush. It's a nice model, actually. The only real fault was the handrails at this side which had pulled towards the ducket at each end, as if the horizontal one was too short. Easy enough to make a new one. I'll have to acquire a guard for it. The French mineral (1/112?) was also given to me; I built the basic kit as part of my demo at Hartlepool and then detailed it according to a photo in Larkin's Wagons of the Early BR Era, including the horizontal raised metalwork (which I assume indicates a repair), rope eyes and safety chain on the door handle. It will also have screw couplings when complete.



Lastly, from a job lot which came from 53A Models, a Perserverance GC Passenger Brake Van. This had been glued together and started to fall apart, so it had to be remade. It was a shame to lose the ery good paint job, but it had to be done. I reprofiled the ends as recommended by Steve Banks and I've tried to capture the same colour, which I rather like.

[jwealleans]

Right, Chas, I've had a look at my implement wagon and I also have a hole in the floor there. What I was going to do (and may have done, I don't recall) was cut a piece of planking as an interference fit in the hole, sloping up with the ramps either side. I've filed the headstock back at an angle (I have no idea what that round thing is0 and was going to support the plastic from beneath with Evostick and then when solid gently file it flat with the headstock so it becomes one smooth surface at the transition. Does that make sense?

[Woodcock29]

Hi Jonathan

How's the ride height on the GC Full Brake? Did you cut the bogies down as per Steve Banks?

I bought a secondhand full 3rd built pretty well by one of my mates here in Adelaide other than his use of the Perseverance bogies. I had planned ahead in the hope he might sell it one day and had a pair of Dan's etched GC bogies waiting. Other than the fact that the instructions bamboozled me in respect to the centre spring arrangements - I made it my way in the end using his parts its looks really good and rides a the right height.

Andrew

[jwealleans]

Morning Andrew,

The bogies are untouched as yet, they're the only part of it I haven't had apart. Next to a D & S NE clerestory it's about 1mm higher so I may have to investigate that as a next step. I don't have any really good dimensioned drawings, so I'm still stumbling along somewhat in the dark with it.

[jwealleans]

Just to show the F6 isn't being completely neglected, the chassis has been fettled and tested prior to the crankpin washers being soldered into place.

https://www.youtube.com/watch?v=Qk_Gebm ... e=youtu.be

[Chas Levin]

Right, Chas, I've had a look at my implement wagon and I also have a hole in the floor there. What I was going to do (and may have done, I don't recall) was cut a piece of planking as an interference fit in the hole, sloping up with the ramps either side. I've filed the headstock back at an angle (I have no idea what that round thing is0 and was going to support the plastic from beneath with Evostick and then when solid gently file it flat with the headstock so it becomes one smooth surface at the transition. Does that make sense?

Hi Jonathan, yes, that makes sense and thank you for having a look. I thought about doing that (putting the flooring up to the tops of the headstocks) but it seems a pity to hide those circular constructions as they're an unusual feature, so I also thought about sloping the floor downwards at about 45 degrees until it's low enough to continue on the horizontal but under the circular things, then boxing in both sides. I might have another go at locating a more informative picture first though... I can't help thinking those round parts must have had some function...

The GC PBV looks very nice - fully agree about the varnished mahogany colour It makes a nice bit of variety alongside the teak...