Preferred height for Kadee couplers on UK 4mm scale models

[Pacific231G]

How about because no one makes a 4mm / 00 (call it what you will) version of the Kadee coupler?  Kadee make them for HO (and a number of other American scales) and I am sure they spent a small development fortune making sure they worked for that scale. To ensure they worked and that installations were repeatable and easy to do they produce a range of supporting tools such as a coupler height gauges, un-couplers and adjusting tools all set to work with the declared HO standard. It must work because there is a long list of copies by other manufacturers but the reason they work is that they are all done to the same standard.

 

So far it seems for 4mm an organisation has declared a height to use for 4mm but no one has produced a coupler to match yet.

 

 

I agree with you that there's no point in establishing a different coupler box height standard for 4mm but that's not what has happened. So far as I know the only 4mm scale organisation that has set a standard for coupler boxes is the Double O Gauge Association and what they've done is to simply and sensibly adopt the same dimensions as NEM362 for H0 and S scale. This sets the height of the upper inside face of the box at 8.5mm (+ or - 0.2mm) from rail top and all the other dimensions are the same. The couplers that Kadeee make for use in standard NEM boxes are designed to put the the coupler head at  the same height (9.93mm to the centre of the knuckle) as all their other H0 couplers based on N. American prototype standards. This also gives the appropriate clearance for the trip pins and enables users of their couplers (like me) to use the standard Kadee height setting gauge. 

 

Since most of the couplers that use these boxes are non-prototypical and set below the buffer beam there's no correct scale height for them to be at so no need for a different standard for 00.

Some people do use Kadee couplers to represent  the "buckeye" couplers used on British (but not European) passenger and some freight stock but they are set higher than  in N. America (39 inches compared with the American 33 inches) based on the height of the traditional British buffer beam. The increased height may make it difficult to use the Kadee trip pins but I think most people who use them do so within rakes rather than at the ends where screw couplings are still used.  

 

FYI  http://www.rgsonline.co.uk/Railway_Group.../GMGN2690%20Iss%201.pdf‎ gives full details including dimensioned drawings for almost all the SG couplers used on Britain's railways 

 

By the way H0 is not an American scale. It was developed in Britain before the war- basing a scale on mm/ft is a dead giveaway of its British origin- and then adopted by almost everyone except the British. 

Edited June 3, 2013 by Pacific231G

[Ravenser]

I was merely offering an alternative solution based on past experience of myself and others, and must claim that I have no knowledge of the adopted heights that other modellers generally use. Once again it seems that the 4mm scale world has been railroaded into somebody else's standard when the "starting with a clean sheet of paper" wouldn't have ended up with the result that seems to be most acceptable to some. The only reason for accepting the HO standard would be for coupling compatability between the two scales, which really isn't a necessity.

 

Considering the advances made in other world markets, I think the only solution would be for a proper UK spec buckeye coupling, instead of the wrongly-handed US overscale knuckle mounted in a HO European coupling mechanism. Anyone who thinks one isn't necessary is ignoring all nationalisation coaches, modern freight vehicles, Gresley coaches, EMU's, etc....

 

As an active member of DOGA I remember the debate on MREMag and elsewhere that led to the standard being issued. It was very obvious from the contributions that the vast majority of those using Kadees on 4mm British outline models were mounting them at the height recommended by Kadee for their HO coupler range . Most of the models sporting NEM pockets had them at the height laid down in NEM 362 - but some didn't , particularly from Bachmann , and this was causing some frustration

 

In other words there was a pretty clear consensus amongst users, and most of the RTR models involved were in line. However, some folk in that debate were attempting to throw dust in everyone's eyes and deflect the complaints about deviant NEM pocket heights with the old cry "you can't say that's the wrong height,  because there's no standard for OO..." Why they wanted to divert the debate into the sand trap I don't know, but it did seem that a few people didn't want to see a clear and consistant agreed position for 4mm RTR emerging (They were'nt arging for a different height , just saying that nobody was allowed to say any particular height was right or wrong - not a constructive approach)

 

Very soon afterwards there was a standard for OO, reflecting the clear consensus of users  expressed in the debate, and as far as I'm aware all subsequently introduced  RTR featuring NEM pockets has had them at the standard height

 

There are really 2 issues here - what height should NEM pockets be on 4mm RTR , and what height should Kadees be mounted at on 4mm stock . In the case of NEM pockets , there are other types of coupling potentially involved - eg some may wish to use Roco close-couplers between coaches , or standardise on a specific type of tension lock.

 

The height of tension locks is a standard that long predates NEM pockets on British models, and  the fact that Bachmann had to produce a second, cranked version of their NEM tension lock for their Mk1s because the NEM pocket is too high speaks volumes..

 

I can't see any real scope for a deadscale UK knuckle coupler when there is an existing very reliable and effective commercial product already available at a modest price . While Kadees may not be a totally accurate model of the real thing, they look very like the buckeye and BSI Tightlock couplings on real coaches and MUs  - and no other type of coupler available looks even remotely like the real thing 

[Dunsignalling]

Yep, early Bachmann wagons with pockets had the height wrong.  Recent releases are correct.  It's still worth checking - the Mk1 coach pockets are not right.  The Kadee height gauge is indispensable.  It's not a big deal to retrofit wagons with incorrect height pockets with No 5 couplings.  I would second the recommendation to stick to the Kadee height standard, especially if you want to play with others.  I don't use the magnetic uncoupling method (prefering to use a pointed stick) but that's a personal choice.  It does let me snip off the trip pins - eliminating the impression that unfitted wagons have automatic brakes. 

 

John

The #5 Kadee is primarily designed to work on US stock where the buffing forces are transmitted through the coupler. It is too short to align the knuckle correctly in relation to the side buffers fitted to (most) UK stock without part of the draft box protruding beyond the buffer beam.

 

This looks fairly unsightly IMHO and a much neater installation is possible using the longer #146 coupler. With this, the whole of the draft box can be set underneath the wagon - all you see is the shaft and knuckle. It also provides the option to use the smaller #252 draft box where mounting space is particularly restricted.    

 

The long Kadee described as "underset" (#141) is the better choice for some tenders on which the area available for mounting is lower than is the case with wagons.

  

John

[Dunsignalling]

The reason many of us adopted Kadees for OO use in the first place was purely operational - they work and, more to the point, they keep on working with very little maintenance. They are also small and neat and hang down in the middle of the vehicle as do most prototype couplers.

 

My own decision to adopt them narrowly preceded getting involved with the Taunton MRG the better part of 20 years ago. They have used Kadees since about 1967 when the choice of types was very small.

 

The wide variety now available makes a tidy job possible on almost any model but that's not to say that I never modify one to suit a particular job; I just know my way around the range and very rarely need to.

 

Sticking with the HO alignment simply ensures they work the way they are supposed to. The same goes for NEM pockets - the standard was created to allow interchangeability of couplers from different manfacturers. Kadee, Roco, Fleischmann et al make their couplers to suit so that (for instance) a Roco coach with Fleischmann couplers will match a Fleischmann coach. It should also make a Bachmann coach with Kadee couplers line up with a Hornby coach with Kadee couplers but sadly, it doesn't. The irony of it all is that Bachmann actually produce their own NEM knuckle coupler heads that DO conform!  

 

As with any engineering "standard", conformity makes stuff work the way it is supposed to with the minimum of effort. Unfortunately, there will always be some modellers who insist on doing things the hard way just for the sake of it! 

 

John     

[Pacific231G]

The only reason for accepting the HO standard would be for coupling compatability between the two scales, which really isn't a necessity.

 

Considering the advances made in other world markets, I think the only solution would be for a proper UK spec buckeye coupling, instead of the wrongly-handed US overscale knuckle mounted in a HO European coupling mechanism. Anyone who thinks one isn't necessary is ignoring all nationalisation coaches, modern freight vehicles, Gresley coaches, EMU's, etc....

I'm not sure what you mean by wrongly handed US overscale. The "Buckeye" coupler long used on much British passenger and some freight stock has the same AAR 10A head as the common "E" type coupler that's been used for years on N. American Railroads. On both sides of the Atlantic the knuckle is right handed (in other words if you look down on the vehicle it's this way round ?)  The standard Kadee head IS somewhat overscale for H0- slightly less so for 00- but the company do also make a scale head coupler. I believe that is still a tad overscale in H0 so may well be spot on for 00.

 

Apart from the drop heads used on older British coaches to allow screw couplings to also be used and the swing heads now used on many freight locos for the same reason,  the biggest difference between Britain and N. America is that the coupler is mounted rather higher in Britain. If I've got my sums right it;s a difference of about 3mm in height between an American H0 coupler and a British coupler in 4mm scale. That doesn't require a different UK spec coupler but does affects how you mount it if you really want to set it exactly at British scale height. If you do that you'd have to adjust or dispense with the Kadee coupler pins and probably make your own height gauge.    

Edited June 4, 2013 by Pacific231G

[Dunsignalling]

I'm not sure what you mean by wrongly handed US overscale. The "Buckeye" coupler long used on much British passenger and some freight stock has the same AAR 10A head as the common "E" type coupler that's been used for years on N. American Railroads. On both sides of the Atlantic the knuckle is right handed (in other words if you look down on the vehicle it's this way round ?) The standard Kadee head IS somewhat overscale for H0- slightly less so for 00- but the company do also make a scale head coupler. I believe that is still a tad overscale in H0 so may well be spot on for 00.

 

Apart from the drop heads used on older British coaches to allow screw couplings to also be used and the swing heads now used on many freight locos for the same reason, the biggest difference between Britain and N. America is that the coupler is mounted rather higher in Britain. If I've got my sums right it;s a difference of about 3mm in height between an American H0 coupler and a British coupler in 4mm scale. That doesn't require a different UK spec coupler but does affects how you mount it if you really want to set it exactly at British scale height. If you do that you'd have to adjust or dispense with the Kadee coupler pins and probably make your own height gauge.

I know of several people who have used Kadees as a functional buckeye coupler mounted through gaps cut in the buffer beams of r-t-r coaches. The extra height makes the uncoupling 'tail' too short to function so may as well be cut off.

 

It is also necessary to modify or replace the moulded corridors to allow them to be compressed or pushed back into the bodyshell.

 

The practice is usually confined to coupling coach-to-coach where the coupler is hidden by the corridors and "shuntability" is not required. This use of Kadee couplers as a resource for semi-scale coupling of coaches is perfectly reasonable but it bears no resemblance to using them as general couplers. To treat locos or wagons the same way would ruin their appearance.

 

A "normal" (#5 or #146) Kadee, mounted directly under an OO r-t-r wagon chassis or loco buffer beam, gives a knuckle height at or very close to the HO standard alignment and ensures they perform fully as intended.

 

John

Edited June 4, 2013 by Dunsignalling

[Pacific231G]

I know of several people who have used Kadees as a functional buckeye coupler mounted through gaps cut in the buffer beams of r-t-r coaches. The extra height makes the uncoupling 'tail' too short to function so may as well be cut off.

 

It is also necessary to modify or replace the moulded corridors to allow them to be compressed or pushed back into the bodyshell.

 

The practice is usually confined to coupling coach-to-coach where the coupler is hidden by the corridors and "shuntability" is not required. This use of Kadee couplers as a resource for semi-scale coupling of coaches is perfectly reasonable but it bears no resemblance to using them as general couplers. To treat locos or wagons the same way would ruin their appearance.

 

A "normal" (#5 or #146) Kadee, mounted directly under an OO r-t-r wagon chassis or loco buffer beam, gives a knuckle height at or very close to the HO standard alignment and ensures they perform fully as intended.

 

John

. I've got a fair number of H0 wagons and locos adapted this way from before when it was usual to fit NEM interchageable boxes. You do have to be careful with the height as Kadees are fairly height sensitive - A Kadee height gauge is a pretty essential tool. One thing I do find is that some close coupling units tend to let the NEM box droop and that's fatal. 

I've always used Kadees since doing some American modelling in the 1970s as though they're not perfect have yet to find anything that works as well. It's just unfortunate that the UIC never succeeded in agreeing on a buckeye based automatic coupler so that European railways are even more stuck with screw couplings than ours. 

[34theletterbetweenB&D]

I know of several people who have used Kadees as a functional buckeye coupler mounted through gaps cut in the buffer beams of r-t-r coaches. The extra height makes the uncoupling 'tail' too short to function so may as well be cut off...

 

 In my experience of using Kadee through coach bufferbeams (and the Bachmann EZ-mate clone as fitted through the bufferbeam on some of their modern wagons such as the HTA) the field from Kadee uncouplers will still usually operate the trip pins and thus the uncoupling function. If it doesn't quite, then straightening the trip pin sufficiently to bring the bottom end closer to Kadee gauge height is all that is required.

 

Echoing earlier posts, where the knuckle coupler is used on the prototype, then a reliable RTR autocoupler that actually looks similar is a complete win; and it looks yet better in 4mm when mounted where it should be rather than dangling below in an HO defined position.

[Dunsignalling]

In my experience of using Kadee through coach bufferbeams (and the Bachmann EZ-mate clone as fitted through the bufferbeam on some of their modern wagons such as the HTA) the field from Kadee uncouplers will still usually operate the trip pins and thus the uncoupling function. If it doesn't quite, then straightening the trip pin sufficiently to bring the bottom end closer to Kadee gauge height is all that is required.

 

Echoing earlier posts, where the knuckle coupler is used on the prototype, then a reliable RTR autocoupler that actually looks similar is a complete win; and it looks yet better in 4mm when mounted where it should be rather than dangling below in an HO defined position.

So you presumably use something else at the ends that will be coupled to the loco when prototype buckeyes would be dropped? Unless it's an A3 or A4 with a corridor tender, of course. Edited June 4, 2013 by Dunsignalling

[298]

Pacific231G, on 03 Jun 2013 - 19:55, said:

 

I agree with you that there's no point in establishing a different coupler box height standard for 4mm but that's not what has happened. So far as I know the only 4mm scale organisation that has set a standard for coupler boxes is the Double O Gauge Association and what they've done is to simply and sensibly adopt the same dimensions as NEM362 for H0 and S scale. This sets the height of the upper inside face of the box at 8.5mm (+ or - 0.2mm) from rail top and all the other dimensions are the same. The couplers that Kadeee make for use in standard NEM boxes are designed to put the the coupler head at the same height (9.93mm to the centre of the knuckle) as all their other H0 couplers based on N. American prototype standards. This also gives the appropriate clearance for the trip pins and enables users of their couplers (like me) to use the standard Kadee height setting gauge.

Exactly why or how did UK manufacturers decide to fit NEM boxes to RTR stock anyway...? There is an obvious case on the continent where there are a number of types available, but over here it's just the tension lock. There aren't even packs of larger couplings to retro-fit into the pockets of newer releases in order to retain compatability with existing vehicles, just the smaller type. I dare say part of it is the result of clever marketing, where you can be persuaded to pay for something you don't really need.

 

If we're looking at prototypical accuracy, the NEM pocket does allow owners of the 5-plank wagon in the first photo to quickly remove the coupling and fit 3-links, but you're still left with more work to remove the box when screwing the coupling to the underside (as Mainline used to do) is alot less obtrusive, and less work...!

[47137]

Exactly why or how did UK manufacturers decide to fit NEM boxes to RTR stock anyway...?

 

I will hazard a guess (always a bit reckless in these forums!) that the RTR manufacturers wanted to give purchasers of locomotives the opportunity to fit scale couplings (usually screw couplings) and brake pipes/hoses instead of tension locks, for example on the 'front' of a loco or on both ends of a model in a display case. The pocket lets people install a standardised working coupling (though not remove it) without the use of tool.

[298]

 In my experience of using Kadee through coach bufferbeams (and the Bachmann EZ-mate clone as fitted through the bufferbeam on some of their modern wagons such as the HTA) the field from Kadee uncouplers will still usually operate the trip pins and thus the uncoupling function. If it doesn't quite, then straightening the trip pin sufficiently to bring the bottom end closer to Kadee gauge height is all that is required.

 

Echoing earlier posts, where the knuckle coupler is used on the prototype, then a reliable RTR autocoupler that actually looks similar is a complete win; and it looks yet better in 4mm when mounted where it should be rather than dangling below in an HO defined position.

 

 

So you presumably use something else at the ends that will be coupled to the loco when prototype buckeyes would be dropped? Unless it's an A3 or A4 with a corridor tender, of course.

 

Some 08's, EWS 66* or 67, 33/1, 73, 89, 90/0, or 91...? All would use their buckeye couplings to couple to stock. Just to prove the real railway has the same issue, there have been instances where modern wagons have been designated non-revenue and run as coupling conversion vehicles where the loco and stock were incompatable. There was even an instance where a pair of 73's were dragged up to Scotland to be used as converters....!! 

 

Getting back to a modelling point of view, how can you couple to something like the Bachmann EWS HTA hopper when there are no outer vehicles available, and the scale height coupling on the wagon is higher than the Kadee in the loco's NEM pocket...?

 

(* except 66001 and 66002)

[Ravenser]

Exactly why or how did UK manufacturers decide to fit NEM boxes to RTR stock anyway...? There is an obvious case on the continent where there are a number of types available, but over here it's just the tension lock. There aren't even packs of larger couplings to retro-fit into the pockets of newer releases in order to retain compatability with existing vehicles, just the smaller type. I dare say part of it is the result of clever marketing, where you can be persuaded to pay for something you don't really need.

 

If we're looking at prototypical accuracy, the NEM pocket does allow owners of the 5-plank wagon in the first photo to quickly remove the coupling and fit 3-links, but you're still left with more work to remove the box when screwing the coupling to the underside (as Mainline used to do) is alot less obtrusive, and less work...!

 

 

I remember that when DOGA started in the mid 90s , it did call for improved specification OO models and NEM pockets were one of the items mentioned. However I don't remember any real emphasis being placed on that particular item on the shopping list - most  of the effort went into pushing for better wheels than the then current Hornby and Lima efforts - and I certainly wouldn't claim "it was DOGA what done it".

 

I don't think the idea originated with them - it was one of those things which was cited in the 90s when comparisons were being drawn between the specification of US and Continental HO models and contemporary British outline RTR (along with working lights, all wheel pick up, centre motor drive, plug in sockets for DCC decoders etc...). I think Hornby may have started to offer NEM pockets on new RTR after they bought the wreckage of the Rivarossi Group  and gained a significant presence in the Continental HO market . Certainly it predates their high spec coaches, the first ones of which were the Gresleys (the Mk3s have fixed tension locks). With Bachmann it must have started at least as early as the first of the current Mk1s , and possibly a little ewarlier - say a little after 2000 . Just about the first British outline model to have NEM pockets was Lima's 156, but Lima chose to mount them just above rail level , and to supply the model with Roco close couplers fitted as external couplings , which provoked quite a lot of modern image modellers to ask "so what's the point of that??" 

 

I think the  driving force behind it was the long standing discontent with the tension-lock , especially in its old Volvo Bumper form , which is what you got from Hornby and Lima in the 90s. An NEM socket allows you to get the tension lock off easily . I became involved with a club layout group around 2001, and there was a very strong groundswell of opinion from other members in the group that Kadees should be the standard coupling on the new layout - as far as I recall it was taken as read that they should be mounted at the HO height. This may have been influenced by the fact a number of the group had recently been involved with a US HO layout, which used Kadees. I have a feeling quite a lot of those using Kadees at the time may have been modern image modellers, probably for similar reasons

 

298

Getting back to a modelling point of view, how can you couple to something like the Bachmann EWS HTA hopper when there are no outer vehicles available, and the scale height coupling on the wagon is higher than the Kadee in the loco's NEM pocket...?

 

 

   

I don't recollect a problem. Certainly I saw big Bachmann coal bogie hoppers running several times without any difficulty on that project . I've never owned any of the beasts myself, so I'm a little hazy as to details , but I think the wagons have NEM pockets - you fit the supplied "scale coupler heads" within the rake, and either the supplied tension locks or your own NEM Kadees at the ends .

 

The ability to switch couplers in seconds so that a Kadee fitted vehicle can be retrofitted with a tensionlock if you need compatibility with someone who uses tensionlocks is a significant plus for the pockets

Edited June 4, 2013 by Ravenser

[br-nse-fan]

A much neater installation is possible using the longer #146 coupler. With this, the whole of the draft box can be set underneath the wagon - all you see is the shaft and knuckle. It also provides the option to use the smaller #252 draft box where mounting space is particularly restricted.    

  

John

 

 

John,

 

That is exactly what I did when adding Kadee's to my Lima 6-wheel tankers, as you can see below.  For these, I've simply used the standard box that comes with the coupler. I have used the #252 on other wagons where, as you've said, space is at a premium.

 

Derek

 

 

[Pacific231G]

Exactly why or how did UK manufacturers decide to fit NEM boxes to RTR stock anyway...? There is an obvious case on the continent where there are a number of types available, but over here it's just the tension lock.

 

Well there's never just been the tension lock. The Simplex coupler patented by Sidney Pritchard in 1948 and adopted by both Hornby Dublo and Trix is still being sold by Peco and must by now be well out of patent. AFAIK Tri-ang adopted the tension lock to avoid paying for the rights to use the Simplex and it's probably only their and Hornby's later history that made it so widespread. The NEM standard hinged loop coupler which was actually the coupler used by Maerklin gained a similar dominance in Europe but again was never the only type used. That's partly I suspect because it's such a ghastly coupler to use if you want to do any shunting or have reasonably close coupling. Jouef used to fit a type of tension lock as did Fleischmann.

 

A good number of British modellers have long used other types of commercially available coupler especially the Kadee and the adoption of NEM boxes simply makes that far easier. Though it may seem like heresy it's also worth remembering that a large proportion of buyers simply want to run model trains on fairly simple layouts and may be quite happy to run British and European outline models alongside one another despite the difference in scale. I suspect this is a far larger part of the market for RTR models than many of us realise so for the manufacturers it makes sense to make all their models that use 16.5 gauge track compatible.   

Edited June 7, 2013 by Pacific231G

[47137]

John,

 

That is exactly what I did when adding Kadee's to my Lima 6-wheel tankers, as you can see below.  For these, I've simply used the standard box that comes with the coupler. I have used the #252 on other wagons where, as you've said, space is at a premium.

 

You can also trim down the #242 box which comes with the #146 and similar 'Whisker' couplers. I assembled the coupler and glued up the box, and the next evening cut about 1.5 mm off the back edge of it. This let me line up the inner face of the coupler knuckle with the front of the buffers, and the coupler box is nicely recessed behind the buffer beam. This is another Bachmann wagon, I used a cut-off disc in a mini drill to remove the mount for the NEM362 socket but keep the body retaining screw. This installation puts the coupler shank pivot in about the same location as the flexible mounting of the original socket. (Ignore the use of an overset #149 coupler, this is just a personal experiment).

[Dunsignalling]

298, on 04 Jun 2013 - 20:10, said:

 

Some 08's, EWS 66* or 67, 33/1, 73, 89, 90/0, or 91...? All would use their buckeye couplings to couple to stock. Just to prove the real railway has the same issue, there have been instances where modern wagons have been designated non-revenue and run as coupling conversion vehicles where the loco and stock were incompatable. There was even an instance where a pair of 73's were dragged up to Scotland to be used as converters....!!

 

Getting back to a modelling point of view, how can you couple to something like the Bachmann EWS HTA hopper when there are no outer vehicles available, and the scale height coupling on the wagon is higher than the Kadee in the loco's NEM pocket...?

 

(* except 66001 and 66002)

You can't. That's the problem that inevitably arises with mounting couplers at different heights. They have to be treated as two different couplings; 'outer' vehicles are, as on the prototype, convertor wagons that have to be used to overcome the mis-match.

 

It should be possible to chassis mount (non-NEM) Kadees on locos to obtain the desired height but it will almost certainly involve cutting into the buffer beam and the result won't be pretty or work well on tight curves. I have a number of diesels (22/33/Hymek/Warship) so fitted but at the standard height (which doesn't involve hacking the loco about *). This is so I can fit a full set of pipes, jumpers and fairings (where applicable). The Warships don't like anything much under 30" radii but the shorter locos are mainly OK down to 24" unless propelling.

 

All the successful examples of 'scale height' mounting in 4mm scale that I have seen were within sets of coaches or wagons - the outer ends were fitted with whatever the user had on his locos (not always Kadees). It only works sensibly if you run fixed rakes; re-marshalling (other than in the fiddle yard) isn't really possible.

 

This is why I referred to using Kadees as a 'resource' as opposed to a standard coupler. I use them as the latter, and that's why I stick to the recommended height.

 

John

 

Edit: * As I stated in an earlier post, I have been at this lark for quite a while and (in the case of the Bachmann Warship) my definition of "not hacking the loco about" may be slightly looser than yours!

Edited June 8, 2013 by Dunsignalling

[47137]

I have now fitted Kadee couplings to 21 vehicles (42 couplings), which probably means I should get out more, but I offer my conclusions so far:

1. The most difficult part of the conversion is wading through the Kadee marketing speak. When you have a whisker coupler you will know it is just like their earlier models but with a built-in hair spring, but it is hard to work this out from the literature .. sometimes it seems to only make sense when you know what it is talking about ...

2. If there is a NEM 362 socket in the right place and the vehicle has buffers then I use a #18. If the socket is too far back, e.g. some locos with fairings, then a #19. (I guess a #17 would suit something like a Freightliner chassis with no buffers).

3. Most NEM socket housings seem to be a bit too tall internally, I put a scrap of 0.015" styrene shaved down to fit below the coupler. This stops it drooping in the socket. I have a Roco HO coach with a built-in phosphor-bronze spring in its sockets, which does this properly, but this coach is a one-off for me.

4. If the NEM socket is at the wrong height then get rid of it and put a #146 or possibly a #149, trim down the gear box to fit. You can bend the metal coupler shanks a bit to trim the height of the knuckle.

5. If a loco has screwed-on tension lock couplers, drill out the shank of a #20 and screw it in the place of the original coupler (same as post no. 8). This installation omits the pivot usually present on the shank or the NEM socket and relies on the pivot behind the coupler head ... this seems ok for a loco, I have doubts whether it is suitable for a two similarly equipped vehicles coupled together (Hornby J94):

 

6. If the model has Hornby-Dublo type couplings screwed onto a bogie chassis from above (e.g. the HD Co-Bo!) then use an M3 nut and bolt with a #5 (or better a slightly longer shank), this will be the right height.

7. It is a lot better to use a height gauge than a chosen 'good wagon'. I could not find a Kadee gauge to buy so I made one from a #5 coupling, an M3 screw and a lock nut:

 

8. If you can slip a 0.030" thick steel rule above the rails below the trip pin, its height is pretty close to 1/32".

Having cleared my back log, I think if I stock up on some #146, #18 and a few #20 this will cover most installations.

[Removed a/c]

Thanks for posting your findings Richard. I too have used 18s, 19s 20s and also 5s. I do need to pick up some 146s as I am going to use these on my Hornby MK2s & MK3s. 

 

It is a lot a faffing about and a shame things are not more standard. It is however rewarding when you get everything at the right height and coupled together. :D 

 

Regards

Scott 

[BR60103]

Kadee came out with that variety of couplings because there was no standard.

Interestingly, when there was the most possibility of variation - pre-1960 - they only had 6 variations -- 4/5, 6, 7, 8 and 10.  4 and 5 were the same couplinh but 5 had a box; it's noe the 4. 10 becake the 5&10 and is now 5.

Either the 7 or the 8 had 2 different heights in the same package. The 4 has an odd springing arrangement that used to be common but has all but disappeared.

 

I wonder what happened to 1, 2,and 3.

[Dunsignalling]

I have now fitted Kadee couplings to 21 vehicles (42 couplings), which probably means I should get out more, but I offer my conclusions so far:

 

1. The most difficult part of the conversion is wading through the Kadee marketing speak. When you have a whisker coupler you will know it is just like their earlier models but with a built-in hair spring, but it is hard to work this out from the literature .. sometimes it seems to only make sense when you know what it is talking about ...

 

2. If there is a NEM 362 socket in the right place and the vehicle has buffers then I use a #18. If the socket is too far back, e.g. some locos with fairings, then a #19. (I guess a #17 would suit something like a Freightliner chassis with no buffers).

 

3. Most NEM socket housings seem to be a bit too tall internally, I put a scrap of 0.015" styrene shaved down to fit below the coupler. This stops it drooping in the socket. I have a Roco HO coach with a built-in phosphor-bronze spring in its sockets, which does this properly, but this coach is a one-off for me.

 

4. If the NEM socket is at the wrong height then get rid of it and put a #146 or possibly a #149, trim down the gear box to fit. You can bend the metal coupler shanks a bit to trim the height of the knuckle.

 

5. If a loco has screwed-on tension lock couplers, drill out the shank of a #20 and screw it in the place of the original coupler (same as post no. 8). This installation omits the pivot usually present on the shank or the NEM socket and relies on the pivot behind the coupler head ... this seems ok for a loco, I have doubts whether it is suitable for a two similarly equipped vehicles coupled together (Hornby J94):

 

DSCF9858.jpg

 

6. If the model has Hornby-Dublo type couplings screwed onto a bogie chassis from above (e.g. the HD Co-Bo!) then use an M3 nut and bolt with a #5 (or better a slightly longer shank), this will be the right height.

 

7. It is a lot better to use a height gauge than a chosen 'good wagon'. I could not find a Kadee gauge to buy so I made one from a #5 coupling, an M3 screw and a lock nut:

 

DSCF9861.jpg

 

8. If you can slip a 0.030" thick steel rule above the rails below the trip pin, its height is pretty close to 1/32".

 

Having cleared my back log, I think if I stock up on some #146, #18 and a few #20 this will cover most installations.

You have covered most of the territory in a short time. Your 21 installations were obviously on a well-chosen variety of vehicles to provide such comprehensive conclusions.

 

It took me a lot longer to get that far when I started but I can probably put a '0' on the end of that figure by now!

 

You may not have encountered this yet but two warnings are in order:

 

1. If you are going to improve a model by fitting better wheels, cast buffers etc., make sure you do it BEFORE fitting the couplers. Generally speaking, scale wheels are slightly smaller and scale buffers a bit longer than r-t-r fittings so both will alter the alignment. 

 

2. I still come across the odd new situation even after all this time and r-t-r models sometimes get altered between batches, so always measure before you cut, even if you think you have done the same job before.

 

John

[47137]

1. If you are going to improve a model by fitting better wheels, cast buffers etc., make sure you do it BEFORE fitting the couplers ...

 

2. I still come across the odd new situation even after all this time and r-t-r models sometimes get altered between batches, so always measure before you cut, even if you think you have done the same job before.

 

Wheel diameters and buffers are important. I didn't mention wheels because I thought it would confuse the issue with facts ... I was lucky in that I had converted a lot of this stock to EM, and then regauged it to 00, and I knew I didn't want to change the wheels again. Sometimes scale wheels are a little larger than the originals, e.g. Limby 121 Bubblecar and this could play havoc if you decide to rewheel and/or reset the bogie mounts. There is an unwritten rule, "don't make too many permanent changes", I am thinking especially of the huge moulded-on Lima couplings, where there may be a temptation to saw the whole thing off when you really want to keep part of it as a mount for the Kadee. I have a Mainline J72 I converted to scale 3-links many years ago and I removed all traces of the original coupler mounts. I am now stuck with the 3-links. It may be prudent to run some vehicles with a "converter wagon" until you know what you want to improve. Do the couplings last.

 

I am not sure where this thread can go now, but perhaps it is worth posting a few of shots of fairly ancient and modern implementations of the real thing, a BR Mk1 (retracting buffers) and a class 170 DMU (no buffers). My feeling is, buffers will always make us compromise; any idea of a commercial 4mm scale coupler is a non-starter; and actually, the Kadee looks quite neat.

 

[BR60103]

Should we mention that Kadee operaation can also be affected by slop caused by undergauge wheels? (That's most of the RTR ones). The couplings may not meet up in the right place if the two vehicles are offset the wrong way.

[brian777999]

This is an interesting discussion. I use three link couplers but I have often thought about using Kadees. Has anybody ever done a survey to find out what percentage of modellors use which couplers ? Are Kadees common when modelling British OO gauge ?

[Dunsignalling]

Should we mention that Kadee operaation can also be affected by slop caused by undergauge wheels? (That's most of the RTR ones). The couplings may not meet up in the right place if the two vehicles are offset the wrong way.

It can and probably does happen but I have never had a malfunction which I could definitely blame on it. The most common cause of non-coupling is trying to do it with one or both vehicles on (too sharp) a curve.

 

I operate on a reasonably large layout with plenty of shunting most weeks and most problems that arise are down to couplers moving (old glue letting go or screws coming loose), seizing up due to contamination with paint or oil, or having two that were installed slightly out of line the first place coming together. 

 

John