Hornby - New tooling - Large Prairie

[melmerby]

I've had a good look at the pony truck and compared it to the previous model.

On the earlier one an Airfix type pocket is used but it is at the right height & position for a NEM fishtail coupling.

So I used an NEM Kadee with a "hole" drilled in the middle of the fishtail.

The coupling then just plugs in engaging with the pin like the original Airfix derived one, is at the right height and horizontal position.

[gwrrob]

3 minutes ago, melmerby said:

 

So I used an NEM Kadee with a "hole" drilled in the middle of the fishtail.

 

 

What size is the hole please Keith ?

[The Johnster]

When I returned to the hobby after many years I had the task of retrofitting tension lock couplers to my previous 3-link and screw fitted stock which I was now too short-sighted and shakyhanded to use.  I decided to standardise on NEM tension locks, using Bachmanns for all replacement couplings as Bachmann, it became very rapidly apparent, would be the bulk of new purchases, not from any company or brand loyalty but simply because they happened to produce more of the stuff I wanted than anyone else.  And it turned out to be a much more complex task than I first thought it would.  

 

I assumed that NEM couplers were to a fixed standard, and they probably are for H0 but this is moot for 00.  The first mistake I made was to assume incorrectly that the replacement couplings were to be mounted at a standard distance below the bottom of the solebars and a standard distance out from the buffer beam.  Wrong.  They are to be mounted at a standard bar height above the rail head, and the distance from the buffer beam depends on the overall length of the buffers.  I soon discovered that, even on currently produced stock with NEM t/l couplings, the bar height was not standard above the rail head.

 

Then I discovered more anomalies to what I had thought was a standard fitting.  There is variation in the hook profile, the bar profile, and the profile of the dove tail that fits into the mount.  And the mounts weren't available separately except from Parkside, nor were these standard for all Parkside products either.  On top of this is the problem of mounting fixed couplings to long wheelbase 4 or 6 wheel stock; NEMs are I imagine primarily designed for bogie mounting on US stock.  I have a design clever Hornby LNER long CCT which will not run reliably around a no.4 radius setrack curve without the coupling pulling the adjacent vehicle off the road to the side.

 

I have RTR locos with different coupling profiles on each end, and where pony or bogies are involved the mount is integral with the frame.  I have vehicles on which bodgery has to be employed to mount the couplings in the right place, either by making mounts out of Milliput or using Parkside mounts either cut down or packed up to achieve the correct bar heights.  Bachmann couplings themselves come in 4 types, long, short, straight, and cranked, which hardly confirms the concept of a standard fitting.  

 

For kit coaches and replacement bogies I use Stafford Road printed types which have an NEM pocket printed in, at a height which matches some of my other stock well enough, but not perfectly. 

 

My conclusion, FWIW, is that for the purposes of 00 standard RTR stock and kits, there is no standard coupling whatever the manufacturers claim.  They claim that all tension locks are compatible for a start, and they are very clearly not as soon as you start propelling, even before you get to the first curve!  By and large, RTR and kit manufacturers have standardised on tension lock couplings, and most new toolings for the last 20 years have used NEMs, but some kits and some Railroad items use older types of tension locks and compatibility, already questionable within the NEM framework and even within a single company's output, is not a given!

 

It took me about 6 months of trial and error faffing about before I could claim that my couplings were reliable, by which I mean that a train that I had examined and confirmed to be coupled could be relied on to run the 15 feet of my BLT without parting, and that I could propel any stock anywhere with any loco in whatever formation (except the long CCT, still out of use pending a sorting out).  And on top of this any older eBay bargains or other acquisitions have to be brought into line, never mind issues like that claimed for the Prairie's front coupling...

 

My impression (I am not claiming it to be an established fact) is that not sufficient attention is paid to the mounting of the pockets at the design stage; perhaps there is a culture of acceptance that there is an effective standard, which as we have seen there is not.  I find that, with trimmed or packed Parkside mounts and use of the friendly neighbourhood bodgerigar, in conjunction with the different lengths and crankiness of the Baccy couplers, I can usually get the coupling in a position not far off where I want it, but some vehicles need long couplings that keep the buffer heads too far apart.  This is on a layout with a minimum 3rd radius curve on a 4th-3rd radius setrack turnout; layouts with smaller radius curves, especially reverse curves, may find things more difficult.  

 

The manufacturers really should get this right, but this is the real world, and I am happy that I have developed a system that works for me; I have detailed it here in the hope that it might be of help to others.

Edited July 5, 2020 by The Johnster

[melmerby]

1 hour ago, gwrrob said:

 

What size is the hole please Keith ?

Not sure, possibly about 2mm. It just makes a notch so that the fishtail can clip around the central post in the Airfix style mount.

For security I used a little glue to keep it in place, not so much that I can't get it out again.

[TrevorP1]

1 hour ago, The Johnster said:

When I returned to the hobby after many years I had the task of retrofitting tension lock couplers to my previous 3-link and screw fitted stock which I was now too short-sighted and shakyhanded to use.  I decided to standardise on NEM tension locks, using Bachmanns for all replacement couplings as Bachmann, it became very rapidly apparent, would be the bulk of new purchases, not from any company or brand loyalty but simply because they happened to produce more of the stuff I wanted than anyone else.  And it turned out to be a much more complex task than I first thought it would.  

 

I assumed that NEM couplers were to a fixed standard, and they probably are for H0 but this is moot for 00.  The first mistake I made was to assume incorrectly that the replacement couplings were to be mounted at a standard distance below the bottom of the solebars and a standard distance out from the buffer beam.  Wrong.  They are to be mounted at a standard bar height above the rail head, and the distance from the buffer beam depends on the overall length of the buffers.  I soon discovered that, even on currently produced stock with NEM t/l couplings, the bar height was not standard above the rail head.

 

Then I discovered more anomalies to what I had thought was a standard fitting.  There is variation in the hook profile, the bar profile, and the profile of the dove tail that fits into the mount.  And the mounts weren't available separately except from Parkside, nor were these standard for all Parkside products either.  On top of this is the problem of mounting fixed couplings to long wheelbase 4 or 6 wheel stock; NEMs are I imagine primarily designed for bogie mounting on US stock.  I have a design clever Hornby LNER long CCT which will not run reliably around a no.4 radius setrack curve without the coupling pulling the adjacent vehicle off the road to the side.

 

I have RTR locos with different coupling profiles on each end, and where pony or bogies are involved the mount is integral with the frame.  I have vehicles on which bodgery has to be employed to mount the couplings in the right place, either by making mounts out of Milliput or using Parkside mounts either cut down or packed up to achieve the correct bar heights.  Bachmann couplings themselves come in 4 types, long, short, straight, and cranked, which hardly confirms the concept of a standard fitting.  

 

For kit coaches and replacement bogies I use Stafford Road printed types which have an NEM pocket printed in, at a height which matches some of my other stock well enough, but not perfectly. 

 

My conclusion, FWIW, is that for the purposes of 00 standard RTR stock and kits, there is no standard coupling whatever the manufacturers claim.  They claim that all tension locks are compatible for a start, and they are very clearly not as soon as you start propelling, even before you get to the first curve!  By and large, RTR and kit manufacturers have standardised on tension lock couplings, and most new toolings for the last 20 years have used NEMs, but some kits and some Railroad items use older types of tension locks and compatibility, already questionable within the NEM framework and even within a single company's output, is not a given!

 

It took me about 6 months of trial and error faffing about before I could claim that my couplings were reliable, by which I mean that a train that I had examined and confirmed to be coupled could be relied on to run the 15 feet of my BLT without parting, and that I could propel any stock anywhere with any loco in whatever formation (except the long CCT, still out of use pending a sorting out).  

 

My impression (I am not claiming it to be an established fact) is that not sufficient attention is paid to the mounting of the pockets at the design stage; perhaps there is a culture of acceptance that there is an effective standard, which as we have seen there is not.  I find that, with trimmed or packed Parkside mounts and use of the friendly neighbourhood bodgerigar, in conjunction with the different lengths and crankiness of the Baccy couplers, I can usually get the coupling in a position not far off where I want it, but some vehicles need long couplings that keep the buffer heads too far apart.  This is on a layout with a minimum 3rd radius curve on a 4th-3rd radius setrack turnout; layouts with smaller radius curves, especially reverse curves, may find things more difficult.  

 

The manufacturers really should get this right, but this is the real world, and I am happy that I have developed a system that works for me; I have detailed it here in the hope that it might be of help to others.

Absolutely agree. I’ve ranted about this elsewhere already so I won’t clog up this thread by repeating it here. With similarly hard work I’m now in a ‘reliable situation’ but getting there was frustrating in the extreme. 

[Neal Ball]

2 hours ago, The Johnster said:

When I returned to the hobby after many years I had the task of retrofitting tension lock couplers to my previous 3-link and screw fitted stock which I was now too short-sighted and shakyhanded to use.  I decided to standardise on NEM tension locks, using Bachmanns for all replacement couplings as Bachmann, it became very rapidly apparent, would be the bulk of new purchases, not from any company or brand loyalty but simply because they happened to produce more of the stuff I wanted than anyone else.  And it turned out to be a much more complex task than I first thought it would.  

 

I assumed that NEM couplers were to a fixed standard, and they probably are for H0 but this is moot for 00.  The first mistake I made was to assume incorrectly that the replacement couplings were to be mounted at a standard distance below the bottom of the solebars and a standard distance out from the buffer beam.  Wrong.  They are to be mounted at a standard bar height above the rail head, and the distance from the buffer beam depends on the overall length of the buffers.  I soon discovered that, even on currently produced stock with NEM t/l couplings, the bar height was not standard above the rail head.

 

Then I discovered more anomalies to what I had thought was a standard fitting.  There is variation in the hook profile, the bar profile, and the profile of the dove tail that fits into the mount.  And the mounts weren't available separately except from Parkside, nor were these standard for all Parkside products either.  On top of this is the problem of mounting fixed couplings to long wheelbase 4 or 6 wheel stock; NEMs are I imagine primarily designed for bogie mounting on US stock.  I have a design clever Hornby LNER long CCT which will not run reliably around a no.4 radius setrack curve without the coupling pulling the adjacent vehicle off the road to the side.

 

I have RTR locos with different coupling profiles on each end, and where pony or bogies are involved the mount is integral with the frame.  I have vehicles on which bodgery has to be employed to mount the couplings in the right place, either by making mounts out of Milliput or using Parkside mounts either cut down or packed up to achieve the correct bar heights.  Bachmann couplings themselves come in 4 types, long, short, straight, and cranked, which hardly confirms the concept of a standard fitting.  

 

For kit coaches and replacement bogies I use Stafford Road printed types which have an NEM pocket printed in, at a height which matches some of my other stock well enough, but not perfectly. 

 

My conclusion, FWIW, is that for the purposes of 00 standard RTR stock and kits, there is no standard coupling whatever the manufacturers claim.  They claim that all tension locks are compatible for a start, and they are very clearly not as soon as you start propelling, even before you get to the first curve!  By and large, RTR and kit manufacturers have standardised on tension lock couplings, and most new toolings for the last 20 years have used NEMs, but some kits and some Railroad items use older types of tension locks and compatibility, already questionable within the NEM framework and even within a single company's output, is not a given!

 

It took me about 6 months of trial and error faffing about before I could claim that my couplings were reliable, by which I mean that a train that I had examined and confirmed to be coupled could be relied on to run the 15 feet of my BLT without parting, and that I could propel any stock anywhere with any loco in whatever formation (except the long CCT, still out of use pending a sorting out).  And on top of this any older eBay bargains or other acquisitions have to be brought into line, never mind issues like that claimed for the Prairie's front coupling...

 

My impression (I am not claiming it to be an established fact) is that not sufficient attention is paid to the mounting of the pockets at the design stage; perhaps there is a culture of acceptance that there is an effective standard, which as we have seen there is not.  I find that, with trimmed or packed Parkside mounts and use of the friendly neighbourhood bodgerigar, in conjunction with the different lengths and crankiness of the Baccy couplers, I can usually get the coupling in a position not far off where I want it, but some vehicles need long couplings that keep the buffer heads too far apart.  This is on a layout with a minimum 3rd radius curve on a 4th-3rd radius setrack turnout; layouts with smaller radius curves, especially reverse curves, may find things more difficult.  

 

The manufacturers really should get this right, but this is the real world, and I am happy that I have developed a system that works for me; I have detailed it here in the hope that it might be of help to others.

Have you ever thought of brevity? It just goes on and on.

 

Make your point in shorter detail please!

[dibber25]

Surely NEM is a European standard? The coupling pockets used on US stock are nothing like what I would understand as an NEM pocket. US couplers are generally of the 'knuckle' type and move from side to side and they are seldom bogie (truck) mounted, except on the most basic train-set stock. (CJL)

[melmerby]

21 minutes ago, dibber25 said:

Surely NEM is a European standard? The coupling pockets used on US stock are nothing like what I would understand as an NEM pocket. US couplers are generally of the 'knuckle' type and move from side to side and they are seldom bogie (truck) mounted, except on the most basic train-set stock. (CJL)

Doesn't preclude a US manufacturer making couplings to NEM spec.

Most RTR European stock has body mounted couplings that move from side to side (but aren't knuckle couplers).

 

Maybe we should be modelling Indian Railways?

They use side buffers with knuckle couplers.

[PMP]

3 hours ago, The Johnster said:

 

 

My conclusion, FWIW, is that for the purposes of 00 standard RTR stock and kits, there is no standard coupling whatever the manufacturers claim.   

 

  never mind issues like that claimed for the Prairie's front coupling...

.

 

No manufacturers have made such a claim. 

 

There isn’t an issue with the prairie couplings.

 

 

 

Edited July 5, 2020 by PMP

[34theletterbetweenB&D]

1 hour ago, Neal Ball said:

...Make your point in shorter detail please!

Having gone the same road, for operational reliability choose one maker's version of the miniature tension lock, and use this alone; mounting it at what ever standard height and position you have determined best suits your layout. (The catch, any maker can change their design without notice: there is no defined standard for the product. Best to buy a big heap once the decision is made, to cover all your future anticipated needs.)

[The Johnster]

3 hours ago, Neal Ball said:

Have you ever thought of brevity?

No.

[lofty1966]

2 hours ago, The Johnster said:

No.

Understatement

[Butler Henderson]

Maybe someone with a 3D printer should prepare and sell replacement Kadee stepped shanks, leaving the purchaser to fit the spring ( a particular pain I find on the NEM Kadees) and the knuckle coupling off a NEM Kadee. How is deep is the step needed compared to Bachmanns normal step, i.e. ignoring the Std 4 tank.

 

Edited July 6, 2020 by Butler Henderson

[Ruffnut Thorston]

On the Bachmann small Prairie, and other stock I have dealt with, it seems to be pretty constant, around a millimetre, or the thickness of the NEM coupling...

 

Almost right if the bottom of the pocket was the top, if you can see what I mean?

 

Experimental stepped Kadee couplings...

 

 

 

 

Edited July 6, 2020 by Sarahagain
link added...

[dibber25]

12 hours ago, melmerby said:

Doesn't preclude a US manufacturer making couplings to NEM spec.

Most RTR European stock has body mounted couplings that move from side to side (but aren't knuckle couplers).

 

Maybe we should be modelling Indian Railways?

They use side buffers with knuckle couplers.

MY comment about US stock related to this from the Johnster:

"NEMs are I imagine primarily designed for bogie mounting on US stock."

which is simply not correct. To the best of my knowledge no US stock has NEM pockets though I guess some European stock aimed at the US market might have. The reference to couplings that move from side to side, perhaps needed to be more specific. US knuckle couplers move from side to side on a pivot mounted WITHIN the coupler pocket (the pocket is fixed), whereas NEM pockets contain a fixed coupling and - if necessary - the NEM pocket moves from side to side. Brevity is seldom possible when one has to make one's point so specifically in order to avoid contradiction. I can't imagine why a  US manufacturer would want to make couplings to NEM spec when the US has far superior couplers that are more appropriate to its own rolling stock. Manufacturers can seldom afford to build in considerations to suit a tiny minority of potential customers even if they might like to do so. Hence why so few RTR  models are suited to easy conversion to P4. (CJL)

Edited July 6, 2020 by dibber25

[melmerby]

29 minutes ago, dibber25 said:

MY comment about US stock related to this from the Johnster:

"NEMs are I imagine primarily designed for bogie mounting on US stock."

which is simply not correct. To the best of my knowledge no US stock has NEM pockets though I guess some European stock aimed at the US market might have. The reference to couplings that move from side to side, perhaps needed to be more specific. US knuckle couplers move from side to side on a pivot mounted WITHIN the coupler pocket (the pocket is fixed), whereas NEM pockets contain a fixed coupling and - if necessary - the NEM pocket moves from side to side. Brevity is seldom possible when one has to make one's point so specifically in order to avoid contradiction. I can't imagine why a  US manufacturer would want to make couplings to NEM spec when the US has far superior couplers that are more appropriate to its own rolling stock. Manufacturers can seldom afford to build in considerations to suit a tiny minority of potential customers even if they might like to do so. Hence why so few RTR  models are suited to easy conversion to P4. (CJL)

I was originally confused, but understand what you meant now,

[melmerby]

16 hours ago, PMP said:

 

 

There isn’t an issue with the prairie couplings.

 

 

I'll have to agree with you on that:

 

[The Johnster]

4 hours ago, dibber25 said:

MY comment about US stock related to this from the Johnster:

"NEMs are I imagine primarily designed for bogie mounting on US stock."

which is simply not correct

I imagined wrong then; apologies everyone.  But the point about NEMs on the Hornby long CCT stands...

[TrevorP1]

My 51 arrived from Grimey Times today. I have to say I’m thoroughly pleased. Renumbered to 5175 and weathered using a supplied photo at very reasonable cost. A great big thumbs up is due.

 

After 30 minutes or so running in the loco is very smooth and quiet. As far as the coupling issues mentioned, I’m happy that the front socket is tucked well out of the way because it will never be used. My only criticism is the cab doors which seem to be fixed in the half open position which would never be on the real thing. They may be tweakable but I hesitate to prod at the moment!

[Mark Hamlin]

Mine arrived in NZ, looks fantastic and runs superbly. I have however noticed the slide bars have a distinct downward slope. Plan to correct that by trimming a little material off the motion bracket and a little adjustment.

 

Has anybody else done this yet?

 

Its one of those once you notice it, it always catches your eye moments. Easily fixed, I should add

[Coppercap]

51 minutes ago, Mark Hamlin said:

Mine arrived in NZ, looks fantastic and runs superbly. I have however noticed the slide bars have a distinct downward slope. Plan to correct that by trimming a little material off the motion bracket and a little adjustment.

 

Has anybody else done this yet?

 

Its one of those once you notice it, it always catches your eye moments. Easily fixed, I should add

 

I too want to address the same problem, but haven't even ventured as far as removing the body yet. It's got to be done though. 

I'm not convinced about the splayed front footsteps being a good idea though. 

[MikeParkin65]

17 hours ago, Mark Hamlin said:

Mine arrived in NZ, looks fantastic and runs superbly. I have however noticed the slide bars have a distinct downward slope. Plan to correct that by trimming a little material off the motion bracket and a little adjustment.

 

Has anybody else done this yet?

 

Its one of those once you notice it, it always catches your eye moments. Easily fixed, I should add

Slidebars dont look to be slopping in the photo's in this thread - are you sure they are properly located on your model? I haven't got a Prairie (yet!) but on the recent Princess I found the screw securing the cylinders to the chassis hadnt been fully tightened down which was leaving a gap between the cylinder top and the running plate. Tightening the screw solved this. If I were you I'd look for a construction problem like that before I started trimming the motion bracket.

[MikeParkin65]

16 hours ago, Coppercap said:

I'm not convinced about the splayed front footsteps being a good idea though. 

Agree - think I'd prefer the usual steps as part of the accessory bag for the user to fit if curves permit than factory fitted 'on the wonk'

[Markn]

Looks like the GWR liveried 4154 is next up, with some retailers saying within the next 14 days. Half thought it was due later in the year, so pleasantly surprised as this is the one I've been waiting for.

[Ian Hargrave]

14 hours ago, Markn said:

Looks like the GWR liveried 4154 is next up, with some retailers saying within the next 14 days. Half thought it was due later in the year, so pleasantly surprised as this is the one I've been waiting for.

 
Interesting,though caution here.Chris Trerise on Kernow’s Facebook page who is a usually reliable source of information does not give it a mention.Hornby’s own website doesn’t include it ,though that in itself is of no consequence as it’s exactly  the opposite.  Do they ever really know what comes out of a container until it’s opened ?