Wright writes.....

[Daniel W]

Purely as a matter of interest, the attached diagram shows how I am currently re-chassising three old Airfix ex-LMS 4Fs,

 

CHASSIS DESIGN - MASHIMA + HIGH LEVEL.JPG

 

and I have used exactly the same mechanism to re-chassis three ex-LMS 3Fs from various sources.

 

 

Regards,

John Isherwood.

 

Very interesting to see the High Level gearboxes arrayed over some different diagrams. Out of curiousity,John, which gearbox are you using for the 4Fs and 3Fs? is it the Loadhauler+?

 

Dan

[Worsdell forever]

DJH gearboxes are good but the downside, as Micklner said above, only really good for big locos (I have one in an unfinished DJH Cl 4 tank), they're no good for the stuff I'm building, it would probably tower above the cab roof of my 1001! This is where the High Level ones come into their own, also the service from Chris, I've recently started  taking my part built 'oddball' locos to him and asking him to choose what he thinks will fit, the 1001 and current BTP have been done like this, I think he likes the challenge! The gearbox does show on the 1001 but it was the best we could do for the shape, I do like to hide them if possible, whatever standard the model is built to if the gearbox can be hidden I think it should. Arthur Kimber's kits are, I believe, designed around High Level geaerboxes so this makes life a lot easier. 

 

I think in 4mm we're blessed with a good selection of gearxoxes/mounts in all sizes and ratios at reasonable prices, from the little bit I've done in 7mm the gears are either single stage 30/1 (although I did find a 40/1 once) or a silly expensive motor/gearbox combination.

[Tony Wright]

Tony,

 

Regarding leaving off bits of kits which are either unseen or "get in the way", I have just started (another) DJH A1, kindly donated by my mate Dave, and I refreshed my memory a bit by re-watching your DVD on loco building. The A1 comes with etches for the spring detail behind the drivers but I noticed on the video that you omitted these from the A2 you built. I must confess that missing these off would certainly make the fixing of pickups etc much easier, so was this a deliberate omission?

 

Chas

It was, Chas,

 

I never fit the springs to DJH LNER Pacific chassis (or any other chassis). They get in the way of the pick-ups.

 

From the majority of viewing angles, especially on a layout, they're impossible to see.

 

 

 

 

 

Perhaps, from side-on, with light behind, their omission is noticeable.

 

 

But, as I say, on a layout?

 

Another example of a layout loco as opposed to a glass case one? 

[Chamby]

I’m sure all this stuff about proving weaponry will come in very useful when Tony acquires his Gladiator ‘Bosch buster’ railguns for LB, when Oxford Rail release them later this year. They will, of course, be modified as ‘layout guns’ and appropriately weathered...

 

Better stop now before this gets really silly!

 

Phil.

[Bucoops]

I'd chip in but don't want to be fired.

[Headstock]

Not being a RTR slave, I'm sure that Tony will be making his own 'Bosch buster'. It is to be hoped that the barrel dosn't get in the way of the pick ups.

[John Isherwood]

Very interesting to see the High Level gearboxes arrayed over some different diagrams. Out of curiousity,John, which gearbox are you using for the 4Fs and 3Fs? is it the Loadhauler+?

 

Dan

 

It is indeed - I have assembled and run-in two this afternoon; simplicity itself.

 

Regards,

John Isherwood.

[micklner]

The term 'layout loco' was not 'invented' by me - I think it was first used by Iain Rice. I'm quite happy to plagiarise many of Iain's phrases and labels (though I follow nothing of his practice in the making of chassis).

 

Whether you hate it or not, Mick, I think it has validity. I think it's axiomatic that any modeller should try to aim for the best model they can make, but a loco designed primarily for layout operation must (surely?) have more compromises than one designed for static display in a glass case. 

 

Other differences between the two types (even if both are built to the same standard) would include, at least to me, more sideways movement for the axles in the chassis (though nowhere near the inherent slop in today's RTR locos), the omission of springs (usually invisible, anyway) below the frames where they interfere with pick-ups and the substitution (if necessary) of slightly smaller bogie/pony wheels to give a bit more clearance on curves. 

 

What would one sooner have? A 'layout loco', which, because of the compromises mentioned, runs sweetly, without shorting, interference or derailments, or a 'dead-scale' model (built to the highest standard a modeller might achieve) which runs equally perfectly - but only over a yard of dead straight track? 

 

Sorry Tony, that is not what I was saying, to me and perhaps others what the throwaway/generalisation term "Layout Loco" actually means or implies to a observer maybe taken as below. It is not a valid term when it can be used by people as below.

 

 "Layout Loco" may  mean to the builder , ok that will do , why bother adding the little bits of extra detail such as smokebox handles, a hidden gearbox, a decent paint finish, lettering that is straight and inline and the multitude of other small things that make a good looking/accurate model, or I can't be bothered to do anything else to the Loco or whatever it maybe being made or don't know how too and/or learn how to improve their builds in the future.

 

If then criticised they can simply say its a Layout Loco so what.  Or it can also be used as a way of providing a smokescreen/ a way of ducking out of correct criticism, for a load of old tat that the builder thinks is wonderful, until actually  challenged and again the reply its a Layout Loco . It doesn't do general modelling overall ,any favours. A newcomer reading the expression will think ok , that will do and never try to improve each build they make in the future.

 

 

 

This nothing to do with your builds, which are far better than many others seen elsewhere. I didn't think for a moment that you had invented the phrase.

 

Mick

[Lecorbusier]

Another example of a layout loco as opposed to a glass case one? 

 

When not in use playing trains .... I'd happily put this in a glass case .... but I think I would want a little scenic modelling as a background.

[Chuffer Davies]

Sorry Tony, that is not what I was saying, to me and perhaps others what the throwaway/generalisation term "Layout Loco" actually means or implies to a observer maybe taken as below. It is not a valid term when it can be used by people as below.

 

 "Layout Loco" may  mean to the builder , ok that will do , why bother adding the little bits of extra detail such as smokebox handles, a hidden gearbox, a decent paint finish, lettering that is straight and inline and the multitude of other small things that make a good looking/accurate model, or I can't be bothered to do anything else to the Loco or whatever it maybe being made or don't know how too and/or learn how to improve their builds in the future.

 

If then criticised they can simply say its a Layout Loco so what.  Or it can also be used as a way of providing a smokescreen/ a way of ducking out of correct criticism, for a load of old tat that the builder thinks is wonderful, until actually  challenged and again the reply its a Layout Loco . It doesn't do general modelling overall ,any favours. A newcomer reading the expression will think ok , that will do and never try to improve each build they make in the future.

 

 

 

This nothing to do with your builds, which are far better than many others seen elsewhere. I didn't think for a moment that you had invented the phrase.

 

Mick

 

Hi Mick, 

I agree with your sentiments and those recently expressed by Mr Isherwood.  It all depends on how far you personally want to take a model. 

 

All of my models are by definition 'layout locos' because they are all built to run on exhibition layouts.   I always strive to achieve the same reliability in running that Tony insists on with LB because that is what the viewing public deserve.   I personally enjoy adding the detail that it has been suggested may not be required of a layout loco, and with care the detail does not compromise the running characteristics of the model.  My loco's always include the springs behind the wheels, the sand pipes (including on the tender), and with one very early exception made when I was starting out, motors and gears are completely hidden.  I don't care if the detail wont be seen by the viewing public, I know its there and that's all that matters.  For most 6 coupled loco's this means driving on the rear axle and like John Isherwood I have never thought twice about doing this.  I tend to make the sand pipes from Phosphor Bronze wire because it is significantly more springy than brass or n/silver and as a result if the pipes get caught when cleaning the wheels they spring back to their original shape rather than getting bent out of shape.

 

In my case rather than use High Level gear boxes I have a preference for Portescap units.  These are still available through eBay.  I rarely use the original frames on the gearbox but instead design replacement frames to fit the specific model.  It takes me an evening to fabricate the new sides and to rebuild the drives but I enjoy the challenge and for me the end result is well worth the challenge.

 

There has been some mention in recent threads regarding side play.  Whilst side play is important there are two rules that I follow when building the frames for a model:

1) The front and rear axles (on a 6 coupled loco) should have negligible side play.  The key reason for this is that I use 3 link and Alex Jackson couplings which means that the loco's use their buffers.  Any side play in these axles increases the risk of buffer locking on curves.  

2) I only build about 0.2mm side play each way on the centre axle.  This is still more than is actually needed for 3ft radius curves (do the maths if you don't believe me).  It may seem counter intuitive but even less side play is actually required on an eight coupled loco. 

 

Regards,

 

Frank

[Tony Wright]

No doubt - but I've never understood why.

 

I can demonstrate that driving the rear axle works fine and is, I would contend, more logical as the centre axle of a 'layout loco' requires a fair degree of sideplay.

 

Regards,

John Isherwood. 

I still think it's better to drive off the centre axle of any six-coupled loco, John,

 

My experience has led me to adopt this view because the drive is naturally 'balanced'. Having no need of compensation/spring, I make all my rods rigid. That being the case, where I have driven off the rear axle of a six-coupled or eight-coupled (on the odd occasion), I've always had to open the holes out a bit more in the coupling rods, the further I go away from the drive, especially on the eight-wheelers. This is highly-unscientific I know, and anyone with engineering knowledge will probably say it's nonsense, but it's my anecdotal evidence. 

 

Even with sideplay needed, I've found modern gearboxes allow for this because the 'box or the drive can move from side to side with ease. Unlike on older-style drives, where the motor was bolted to the frames and the drive was a single-stage worm/gear. 

 

The following are a few examples of how I've arranged drives in recent years.

 

 

This is the replacement Comet mechanism I put into an old Airfix/Palitoy 2P, chucking away the ghastly tender drive. 

 

 

With the lid on, the drive is completely hidden.

 

 

Unlike on Hornby's more recent 2P (and 4F), where the drive is visible underneath the boiler. At least it's a proper loco-drive.

 

 

I put SE Finecast chassis underneath two ex-Airfix 4Fs for Richard Wilson, arranging the drives differently.

 

 

From this side, the reversing lever hides the DJH 'box a little on this one.

 

 

On this one, the under-slung drive is completely hidden. Richard weathered both of these. 

 

 

On occasions, 'boxes I've made run quieter one way than the other (it appears to be arbitrary). No matter, I just turn them round, as in the case with both these B1 chassis. They were needed to replace the horrid split-chassis originals. 

 

 

Whichever way round a 'box might be, it's completely invisible beneath a B1 body.

 

 

More tender drive nonsense to be replaced, in a Dean Goods, with a replacement Comet chassis and single stage 'box. 

 

 

Under-slung, the drive is completely invisible. I gave this to Simon Kohler of Hornby as a suggestion for improving the firm's dear old GWR 0-6-0. Then, along came Oxford Rail.

 

 

Even in a relatively small tank, there is no problem in hiding a modern drive. Just look at the appalling thing the Comet chassis I made replaced, underneath an Airfix N2.

 

 

Of course, where a big prototype is concerned, with a barn of space inside the body (as in this Comet V2 chassis for a Graeme King body), hiding any drive is not a problem. As always, I fit the biggest motor I can comfortably fit inside.  

Edited September 6, 2018 by Tony Wright

[John Isherwood]

... to me and perhaps others what the throwaway/generalisation term "Layout Loco" actually means or implies to a observer maybe taken as below. It is not a valid term when it can be used by people as below.

 

Mick,

 

Words are words - they mean different things to different people; that is not a valid reason to label a particular phrase invalid.

 

In this instance, Tony has - on many an occasion - explained in detail his concept of a 'layout locomotive', and the vast majority of those who read his posts understand the context.

 

OK - some lazy modellers will use the term 'layout locomotive' in another context to excuse sloppy modelling - so what?

 

The English language has been used and abused from time immemorial - your dismissal of the term 'layout locomotive' as invalid will have no effect whatsoever in its usage here and elsewhere.

 

Regards,

John Isherwood.

Edited September 5, 2018 by cctransuk

[Headstock]

Hi Mick, 

I agree with your sentiments and those recently expressed by Mr Isherwood.  It all depends on how far you personally want to take a model. 

 

All of my models are by definition 'layout locos' because they are all built to run on exhibition layouts.   I always strive to achieve the same reliability in running that Tony insists on with LB because that is what the viewing public deserve.   I personally enjoy adding the detail that it has been suggested may not be required of a layout loco, and with care the detail does not compromise the running characteristics of the model.  My loco's always include the springs behind the wheels, the sand pipes (including on the tender), and with one very early exception made when I was starting out, motors and gears are completely hidden.  I don't care if the detail wont be seen by the viewing public, I know its there and that's all that matters.  For most 6 coupled loco's this means driving on the rear axle and like John Isherwood I have never thought twice about doing this.  I tend to make the sand pipes from Phosphor Bronze wire because it is significantly more springy than brass or n/silver and as a result if the pipes get caught when cleaning the wheels they spring back to their original shape rather than getting bent out of shape.

 

In my case rather than use High Level gear boxes I have a preference for Portescap units.  These are still available through eBay.  I rarely use the original frames on the gearbox but instead design replacement frames to fit the specific model.  It takes me an evening to fabricate the new sides and to rebuild the drives but I enjoy the challenge and for me the end result is well worth the challenge.

 

There has been some mention in recent threads regarding side play.  Whilst side play is important there are two rules that I follow when building the frames for a model:

1) The front and rear axles (on a 6 coupled loco) should have negligible side play.  The key reason for this is that I use 3 link and Alex Jackson couplings which means that the loco's use their buffers.  Any side play in these axles increases the risk of buffer locking on curves.  

2) I only build about 0.2mm side play each way on the centre axle.  This is still more than is actually needed for 3ft radius curves (do the maths if you don't believe me).  It may seem counter intuitive but even less side play is actually required on an eight coupled loco. 

 

Regards,

 

Frank

 

Evening Frank,

 

with the exception of the Portescap, you could be describing my recent B16/1. Funny how similar conclusions can be reached independently but for slightly different reasons. With regard to sideplay, the locomotive is set up to an identical specification to that mentioned but in my case to allow the side control on the bogie to guide the leading driving wheels into a curve, thus allowing the centre set to move out to accommodate. The gear box is on the rear axle, hiding it from view and the coupling rods are jointed at the middle axle. The B16 bogie is notoriously close to the cylinders but the set up is working well on a three foot radius curve with plenty of clearance without recourse to cutting lumps out of the cylinders or leaving off the drain pipes. The chassis is electrically dead, my preferred method, so it doesn't matter what gubbins I choose to put on it as regards sand pipes etc. The chassis as provided did not come with any spring detail, I made my own. I've never seen springs as a problem with regard to fitting pick ups.

Edited September 5, 2018 by Headstock

[Chuffer Davies]

Evening Frank,

 

with the exception of the Portescap, you could be describing my recent B16/1. Funny how similar conclusions can be reached independently but for slightly different reasons. With regard to sideplay, the locomotive is set up to an identical specification to that mentioned but in my case to allow the side control on the bogie to guide the leading driving wheels into a curve, thus allowing the centre set to move out to accommodate. The gear box is on the rear axle, hiding it from view and the coupling rods are jointed at the middle axle. The B16 bogie is notoriously close to the cylinders but the set up is working well on a three foot radius curve with plenty of clearance without recourse to cutting lumps out of the cylinders or leaving off the drain pipes. The chassis is electrically dead, my preferred method, so it doesn't matter what gubbins I choose to put on it as regards sand pipes etc. The chassis as provided did not come with any spring detail, I made my own. I've never seen springs as a problem with regard to fitting pick ups.

 

Hi Andrew,

I think the key difference for you and I is that you are working in OO and I in EM.  Being a traditional GW modeller the vast majority of loco's with front bogies or pony trucks also have outside cylinders and as a result this means that there is precious little room between the front crank pin and the slide bars.  In many cases the front crank pin co-locates with the back of the crosshead leaving still less wiggle room.  This means that there is no option but to limit the side play in the leading axle.  Despite this, and like you, I still build side control into the leading bogie or pony truck to reduce the tendency of any wheels touching the back of the cylinders.  This will also, as with your models, result in the bogie guiding the front of the loco into the curves because there is still 'slop' between the wheel flanges and the inside of the rail.  Whilst in EM by my calculation this slop is around 0.5mm less than in OO fine scale there is still a measurable amount.

 

My introduction to modelling GN atlantics has led to me developing a new approach (for me at least) into the design of the frames for such locomotives.  My first experience of LNER modelling was to cure a white metal C13 (I think that was the class) locomotive which suffered from the bogie wheels repeatedly shorting out on the underside of the footplate on irregular track.  Rather than hack out the white metal from the underside of the footplate (which had already been attempted unsuccessfully by the loco's owner) I rebuilt the frames such that the front of the locomotive sat on the bogie's pivot preventing the tendency for the locomotive to nose dive.  The driving wheels were then compensated using twin beams with the axle bushes soldered to the beams.  The frames just had slots to clear the axle bushes.  Job Done so to speak.

 

When I built my C12 (a picture of which has previously appeared on this blog) I repeated the approach but wanted/needed to improve the control of the side play at the front buffers.  To achieve this I moved the bogie's pivot to directly above the rear bogie axle.  The bogie has no side play at the pivot and so this axle performs the same role as the leading axle on a 6 coupled locomotive.  I therefore built a small amount of side play into the leading driven axle.  The leading bogie wheels still steer into the curves and a sprung rubbing plate close to the bogie's front axle provides down force on the front wheels to ensure they stay firmly planted on the track.  

 

Cosmetically the look of the locomotive is improved because this approach removes the need to file a clearance in the frames to allow the rear bogie wheels to pass underneath on curves. 

 

I am now building the same solution into a new set of etches for replacement frames for a Bachmann C1.

 

Regards,

 

Frank           

[Tony Wright]

Some of the solutions for getting various types of chassis to work properly are quite sophisticated and require a high degree of modelling skill. My thanks for explaining how they're done. Though I think I have a modicum of 'skill', nothing I'm involved with could ever be called sophisticated. 

 

I suppose I adopt a simpler approach to making my own chassis, in both OO and EM. They might be listed thus..............

 

Everything rigid, including the 'rods. 

 

The centre axle of a six-coupled loco being set a 'fag-paper' thickness higher than the outer ones, to obviate the dreaded see-saw effect on less-than-perfect track.

 

Though front bogies might be sprung, either by a small coil spring on the pivot or a 'bend' in the pivoting strip attaching the bogie to the frames, the bogie takes no part in guiding the loco into curves. In fact, they work just as well without them.

 

Driven off the centre axle, or the third axle of an eight-coupled. The exception to this 'centre-axle drive is a 9F, where I drive off the fourth axle, using a sort of 'U'-shaped drive on its side. 

 

Because my locos have live chassis, some have a thin smear of Araldite applied to the front frames or the inside of cylinders to prevent shorting on curves. 

 

Romford/Markits drivers all round.

 

For EM, especially on the likes of a Thompson Pacific (which has less clearance than any GWR loco between the little end and the front crosshead), I plug the cylinders with solder and drill out new holes for the piston rods/slidebar ends 1 mm further out. This subterfuge is completely invisible once the motion is fully-erected, and the necessary clearance is achieved. 

 

Fitting the biggest motor I can get inside. Now, I usually use at least a two-stage gearbox as well.

 

For 4-4-0s and some 4-6-0s, I let the front tender axle float by elongating its bearings 'northwards'. The front of the tender then rests on the drawbar of the loco, aiding adhesion. I then fill the front of the coal space with lead - hidden with coal when the loco is painted.

 

This list is descriptive, rather than prescriptive. The methods suit me, and with loco-build number 500 approaching in 45 years of my making these things, I've either reached a 'practical' solution for erecting sweet-running mechs down the decades, or there is a mountain of duds out there! 

Edited September 6, 2018 by Tony Wright

[jwealleans]

Frank,

 

Can we see one of the bogie arrangements you're talking about? I like the idea, I have an A8 to try to adapt for a friend to get around just this issue but a couple of questions spring to mind. One is, how do you attach the bogie in an accessible manner if it's directly above the axle and the second is where do you find soft springs to fit above the bogie.

[46256]

A big thank you to all the  contributors to the motor gearbox, side play, chassis work in general discussion, this is why I keep returning to this thread in between working on my own creations

 

Best wishes Brian

[richard i]

The chassis debate to me is like people discussing which traction should be used on the railway, steam/ diesel/ electric. It can get heated at times and yet; All have their pros and cons, some are more complicated than others......but as long as they work then great. As long as no one raises that I forgot to put horse into the mix. That is the equivalent of the clockwork?

Richard

[Worsdell forever]

The chassis debate to me is like people discussing which traction should be used on the railway, steam/ diesel/ electric. It can get heated at times and yet; All have their pros and cons, some are more complicated than others......but as long as they work then great. As long as no one raises that I forgot to put horse into the mix. That is the equivalent of the clockwork?

Richard

 

The horse walking on the treadmill on the locomotive was disqualified wasn't it?

[Barry Ten]

Frank,

 

Can we see one of the bogie arrangements you're talking about? I like the idea, I have an A8 to try to adapt for a friend to get around just this issue but a couple of questions spring to mind. One is, how do you attach the bogie in an accessible manner if it's directly above the axle and the second is where do you find soft springs to fit above the bogie.

 

I'd like to know about soft springs as well. I've tried using the ones from biros, stretched out and cut to length but they're very variable from pen to pen. I'm not sure if they can be soldered.

 

Al

[jwealleans]

Our man at Little Bytham has submitted another film.... while observing the apparently failed Claud on the M & GN overbridge, he caught a most unusual machine working what looks like an excursion from the GC Area towards London.

 

 

YouTube has done something unspeakable to the quality of this one, on the original you can see just how unusual this locomotive is.

Edited September 6, 2018 by jwealleans

[Clive Mortimore]

Our man at Little Bytham has submitted another film.... while observing the apparently failed Claud on the M & GN overbridge, he caught a most unusual machine working what looks like an excursion from the GC Area towards London.

 

 

YouTube has done something unspeakable to the quality of this one, on the original you can see just how unusual this locomotive is.

Jonathan

 

I am no steam expert but isn't the Claud just resting not failed?

 

As for Mr Bullyboyed's processed meat tin, is that the secret one he had built  before he left Doncaster which Tomo rebuilt to the first B1?

[Headstock]

Hi Andrew,

I think the key difference for you and I is that you are working in OO and I in EM.  Being a traditional GW modeller the vast majority of loco's with front bogies or pony trucks also have outside cylinders and as a result this means that there is precious little room between the front crank pin and the slide bars.  In many cases the front crank pin co-locates with the back of the crosshead leaving still less wiggle room.  This means that there is no option but to limit the side play in the leading axle.  Despite this, and like you, I still build side control into the leading bogie or pony truck to reduce the tendency of any wheels touching the back of the cylinders.  This will also, as with your models, result in the bogie guiding the front of the loco into the curves because there is still 'slop' between the wheel flanges and the inside of the rail.  Whilst in EM by my calculation this slop is around 0.5mm less than in OO fine scale there is still a measurable amount.

 

My introduction to modelling GN atlantics has led to me developing a new approach (for me at least) into the design of the frames for such locomotives.  My first experience of LNER modelling was to cure a white metal C13 (I think that was the class) locomotive which suffered from the bogie wheels repeatedly shorting out on the underside of the footplate on irregular track.  Rather than hack out the white metal from the underside of the footplate (which had already been attempted unsuccessfully by the loco's owner) I rebuilt the frames such that the front of the locomotive sat on the bogie's pivot preventing the tendency for the locomotive to nose dive.  The driving wheels were then compensated using twin beams with the axle bushes soldered to the beams.  The frames just had slots to clear the axle bushes.  Job Done so to speak.

 

When I built my C12 (a picture of which has previously appeared on this blog) I repeated the approach but wanted/needed to improve the control of the side play at the front buffers.  To achieve this I moved the bogie's pivot to directly above the rear bogie axle.  The bogie has no side play at the pivot and so this axle performs the same role as the leading axle on a 6 coupled locomotive.  I therefore built a small amount of side play into the leading driven axle.  The leading bogie wheels still steer into the curves and a sprung rubbing plate close to the bogie's front axle provides down force on the front wheels to ensure they stay firmly planted on the track.  

 

Cosmetically the look of the locomotive is improved because this approach removes the need to file a clearance in the frames to allow the rear bogie wheels to pass underneath on curves. 

 

I am now building the same solution into a new set of etches for replacement frames for a Bachmann C1.

 

Regards,

 

Frank           

 

Afternoon Frank,

 

apologies for the late reply, life, work and wheel cleaning. The leading crank pin isn't an issue on the B16, as all three cylinders on the prototype are driven off the leading axle. What is an issue is that it is a rather long nosed beast, with the rear bogie wheel centre located 7' 8'' forwards of the leading driving wheel centre. The total wheelbase of the locomotive is greater than a Castle and the overthrow of the front end is somewhat more exaggerated than on a Hall but with a similar arrangement to the outside cylinders. NER locomotives were the complete opposite of GN locomotives, having long wheelbases rather than cramped up ones as in your Atlantic.

 

I suspect that the wheelbase may be a little two long for a fixed pivot at the rear of the bogie, instead I made it float in a slot via a center pivot. I don't much like bogie centre pivot springing, it seems to do little but concentrate force in a small area were you don't want it and has no true side control. If it works, it is usually down to pure brute force. Like your GN locomotives, my bogie control mechanism spreads its downward force over the front axle, this is achieved via a left and right arms that act as shock absorbers. Most importantly they can act independently of one another and they are designed to bare on the bogie side frames and act as a self centering mechanism. With this in mind, it would seem pointless having excessive play in the leading driving wheels, that would only courage it to go wandering off in the opposite direction from the bogie, something that I have no wish to encourage.

[Tony Wright]

Our man at Little Bytham has submitted another film.... while observing the apparently failed Claud on the M & GN overbridge, he caught a most unusual machine working what looks like an excursion from the GC Area towards London.

 

 

YouTube has done something unspeakable to the quality of this one, on the original you can see just how unusual this locomotive is.

Thanks Jonathan,

 

What a pity.

 

Isn't the Bulleid 2-8-2 pulling the rake containing the Barnums and the Tourist Buffet Car? What gorgeous vehicles, which, thankfully show up all right in the DVD we shot for release in the November issue of BRM. It was signed-off today, and I hope folk like it. 

[rowanj]

 

I suspect that the wheelbase may be a little two long for a fixed pivot at the rear of the bogie, instead I made it float in a slot via a center pivot. I don't much like bogie centre pivot springing, it seems to do little but concentrate force in a small area were you don't want it and has no true side control. If it works, it is usually down to pure brute force. Like your GN locomotives, my bogie control mechanism spreads its downward force over the front axle, this is achieved via a left and right arms that act as shock absorbers. Most importantly they can act independently of one another and they are designed to bare on the bogie side frames and act as a self centering mechanism. With this in mind, it would seem pointless having excessive play in the leading driving wheels, that would only courage it to go wandering off in the opposite direction from the bogie, something that I have no wish to encourage.

 

Andrew

 

I found getting the leading bogie of both my PDK B16's to work was problematic, and suspect it was more by luck that judgement that I got them to (usually) work. So if you could post a photo of your solution, that would be excellent. I'm not quite following the description of the "shock absorbers".

 

Catching up on this thread, I noted the discussion on "layout locos". a term I use for my own efforts. While I agree that it should not be used as an excuse for accepting a lesser quality than one is capable of at ones' skill level, as long as one is doing ones' best to produce a working model and it then runs successfully on a layout, what else would you call it? As for posting photos of less than pristine build, I am foolish enough to do so from time to time, How else is one to encourage folks to take the plunge without feeling inferior to the best work of folk who are essentially of the standard of professional modellers? 

 

John