Could somebody explain the difference between couplings?

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BobDM
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Could somebody explain the difference between couplings?

Postby BobDM » Thu Jul 18, 2019 7:46 pm

I keep coming across references to different types of couplings like Kadee and NEM. What is the difference and which is best for OO guage?

Any guidance gratefully received!

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Mountain
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Re: Could somebody explain the difference between couplings?

Postby Mountain » Thu Jul 18, 2019 8:22 pm

NEM is a convenient attachment method to slot couplings into. It is a fairly recent development in 00 gauge. The older method was a three point method which has a central screw. This method I found personally to be more reliable except that the NEM method seems to have gained more popularity these days.
The couplings themselves. In 00 gauge, tension lock couplings are by far the most popular. They are generally reliable and come in three sizes, small, medium and large. Generally the largest size enables ones stock to go round the sharpest bends while the narrowest tends to blend in better as lets face it. Rarely do model couplings liik the part unless they are exact copies or built to a similar design. It does help though in reliability to try to use one coupling size, as though large to small etc do couple, if there is going to be any issues, it is almost guaranteed that diffeeent coupling sizes will be the most likely cause.
Now Kadees. They are not cheap, but they are popular with Americal modellers because they look like the American knuckle coupler. While they are said to be fiddly to set up and need to be set up with precision, those who perservere have enjoyed the way they operate, as they are automatic couplings. Tension lock mentioned earlier are semi automatic.
Kadees work well when set up right and many UK modellers have converted to them, but for me, they just don't look right on most UK stock. They do resemble buck eye couplings used on UK coaches, and they do resemble a little modern DMU couplings. However, for most UK stock they don't look right in my oppinion. Having said that, many are happy with them so fair enough!
There are also other choices. The old Sprat &Winkles I have tried and they do work well. I have mine for sale as I am not staying in 00 gauge. They are also automatic couplings.
D&G are also another coupling for 00.

Generally though, one issue is to convert means patience, cost and time. Also if you are wanting to sell your stock in the future then tension lock couplings tend to fetch higher prices.

I also forgot to mention two other choices. Peco used to be pupular in 00 gauge and were used by Hornby Dublo and others at ont time.
Also, for finescale modellers who don't use sharp curves, copying the prototype appeals with screw link or three link couplings just like the real thing. However, there are manual couplings, and can't be used on anywhere near sharp curves due to buffer locking issues. To couple needs to be done via a piece of wire to hook the loop over the hook, which is somewhat testing on ones patience and eyesight! It is not easy in 0 gauge let along 00!

I am in a larger scale... Narrow gauge of 0 gauge, which I make my own couplings which don't cost a lot. Actually pennies! But they are manually operated (Though far, far easier then 00 gauge 3 link or screw link) and they are made from drawing pins acting as the centrally mounted buffers, and have drop loops made from paper clips. Cheap, cheerful and simple. And they look the part.

The photos are from an old book I have published back in 1948... Trying to remember the title. I will ammend this when I remember it. I think it is called "Building 4mm Scale Rolling Stock" by Michael Longridge. I will conform this when I find the book. The pictures of the book are the early forms of what later became tension lock which is popular today.
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heda
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Re: Could somebody explain the difference between couplings?

Postby heda » Fri Jul 19, 2019 10:40 am

I think Mountain covered it pretty well.
I'm fitting Kadee couplings, the main reason being I really don't like the look of the tension lock couplings. The benefit of Kadee is the uncoupling, I'll try to explain the best I can. But have attached a You Tube link that may explain it better.
I've fitted magnets at the entrance to the sidings, when the train is running normaly the tension on the couplings holds them together, if you pause over the magnets they uncouple, pull forward slightly then reverse and push the wagons back and the couplings don't re couple so the wagons can be left, when you back up again they recouple and away you go.
Fitting is pretty staightforward, there's lot's ofinformation online.
Hpoe this helps.
Dave

https://www.youtube.com/watch?v=fWr6WOlnVGk

Bigmet
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Re: Could somebody explain the difference between couplings?

Postby Bigmet » Fri Jul 19, 2019 11:18 am

BobDM wrote:I keep coming across references to different types of couplings like Kadee and NEM. What is the difference and which is best for OO gauge?

First, NEM is nothing to do with couplings specifically, it is a standards setting body in Europe for model railway product.

What this means is that a vehicle with an NEM conforming coupler pocket can accept a selection of RTR coupler designs.

The Kadee design is without doubt the best of the RTR choices for both autocoupler performance and having an appearance that is related to the widely used knuckle coupler.

There are many other choices, some of them 'horses for courses'.

Hornby for example pack a long shank Roco design coupler for use on their coaches with close coupling mechanisms.

Bachmann have taken to using the old style HO 'hook and loop' between cars in DMU sets, and rigid bar links, some with power conduction between EMUs. On some modern goods wagons which are knuckle coupled in reality, they fit their Kadee clone, and as a result these are the most accurate RTR OO wagons you can buy - complete with a coupler that looks like the real equipment...

Personally, I use three RTR couplers:
On steam era wagons, the Bachmann miniature tension lock, (but I mutilate the NEM pocket for closer coupling) as it gives easily the best loose coupled effect. The wagons buffer up when pushed, open out to 2mm between buffer heads when pulled (needs a 24" minimum radius on the layout, not possible with set track, leave the couplers at supplied spacing).

I use the 'Brian Kirby' or 'BK' mod to allow magnetically actuated uncoupling with these. Happily the Kadee magnetic uncouplers also operate BK modded Bachmann MTL's.

Between coaches with close coupling mechanisms a mix of original Roco and Hornby long shank Roco couplers (fully compatible coupler heads) because the rigid linkage these create means that the gangways are in contact on straight or nearly so track for excellent appearance, and the mechanisms then act correctly to space the coaches out to take curves and restore to gangways in contact on returning to straight track.

On the ends of all passenger trains and on locos assigned to hauling them, Kadees for their peerless autocoupling performance and close resemblance to the couplers that all advanced UK coach designs had from the late nineteenth century.

BobDM
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Re: Could somebody explain the difference between couplings?

Postby BobDM » Fri Jul 19, 2019 6:54 pm

Thanks guys for taking the time to explain this so thoroughly. I think I will stick to the couplings that are supplied.

I seem to remember reading someone complaining in one of the magazines about Hornby and Bachmann coupling systems not being as compatible as they should be, so I might try running sets made up from stock made by the same manufacturer.

Mike Parkes
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Re: Could somebody explain the difference between couplings?

Postby Mike Parkes » Fri Jul 19, 2019 9:43 pm

Tension lock styles vary within makes so its best to use stock that stays together regardless of its origins. Generally different styles of TL couplings will work together and if you have problems consider, if they are fitted in NEM sockets, simply swopping couplings about. On shunting locos it might be worth removing the hooks. I now use Kadees but when I used TLs I made a card index up for each wagon with coloured dots indicating the type of TL fitted to each end, on some wagons I altered them to a different style at each end. The cards for the wagons sat in sidings would be randomly selected and a train assembled trying to match the TL styles or if not then coupling together ones known to work well together. A definite no was coupling a wagon with the tiny Airfix TL coupling to one with a huge Lima TL coupling - the Airfix hook being a tight fit on the chunky Lima loop leading to derailments on curves, while alternatively the Lima hook was too tight a fit into the Airfix loop

Bigmet
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Re: Could somebody explain the difference between couplings?

Postby Bigmet » Fri Jul 19, 2019 10:43 pm

BobDM wrote:Thanks guys for taking the time to explain this so thoroughly. I think I will stick to the couplings that are supplied.

I seem to remember reading someone complaining in one of the magazines about Hornby and Bachmann coupling systems not being as compatible as they should be, so I might try running sets made up from stock made by the same manufacturer.

Good plan, you will get the best reliability by using a single manufacturer's pattern of the miniature tension lock within a train.

Once you start looking closely, you will find it easy to differentiate: Hornby's is slightly larger, the hook a little longer and hinges right up to the vertical.

And here's where the NEM coupler pocket works for you. If you find you want to make a train from a mixture of wagons from Hornby and Bachmann, (and maybe Dapol, Oxford, Heljan and others) you can swap the couplers between the wagons to provide a single type in the train. (For some years I operated a swap scheme with a friend, he took the Hornby couplers from me, and gave me Bachmann type in return.)

muggins
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Re: Could somebody explain the difference between couplings?

Postby muggins » Sat Jul 20, 2019 6:36 am

Bigmet wrote:...On steam era wagons, the Bachmann miniature tension lock, (but I mutilate the NEM pocket for closer coupling) as it gives easily the best loose coupled effect. The wagons buffer up when pushed, open out to 2mm between buffer heads when pulled...


Bigmet, have you by any chance described your NEM-mutilation process somewhere on here? I'd love to know how you do it :}

Bigmet
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Re: Could somebody explain the difference between couplings?

Postby Bigmet » Sat Jul 20, 2019 11:04 am

NEM Coupler Plug and Pocket Shortening Modification for close coupling of four wheel wagons.

Read first and think about it.

For this to work well, you need to use a single manufacturer's version of the tension lock coupler. (Just for a start there are significant dimensional differences between the versions made by Bachmann and Hornby.)

I have only done this modification with the BACHMANN version. I see no reason it should not work with the HORNBY version, so if that's what you want to do, then please report your experience. And of course there are others , DAPOL, OXFORD, HATTONS, etc.

How close coupled you can get the wagons depends on their length and the tightest radius they have to work on. This is where you have to test your wagons on the tightest curve you want them to run on. No one else can do this for you, as it is the track formation on your layout that defines what is possible.

My modification process:

Take the couplers out of the pockets.

I use a pair of kitchen shears, designed to cut bone when filleting, and snip the outside end off the pocket, and make a similar shortening to the coupler 'tail' that plugs into the pocket.

I do the cutting by eye (precision stuff this!) guided by the following check. With the wagon upside down, the coupler is placed above the pocket, with the bumper bar face in the same plane as a line drawn across the buffer faces. Look at where the rear of the pocket then comes on the tails and make the cut just beyond that point. Remove the pocket from the vehicle and cut the same amount off the front of the pocket. Model wagons do vary a little in coupler pocket mounting position, usually within the permitted tolerance in the NEM specification.

In my case roughly 2mm comes off, that's for my 24" minimum radius for short wheelbase wagons only, and nominal 3' minimum radius points.

Reassemble and test on your tightest layout curve that they will still go round without binding on the inside buffer faces, and on straight track that they buffer up. You should be able to put a straightedge across the bufferfaces and the front of the 'bumper bar'. Enjoy the loose-coupled effect once you have done a trainload.

The cutting action typically deforms the soft plastic enough that the trimmed coupler stays in the shortened pocket. But if they don't, a little cyano fixes. This also allows position adjustment after cutting if you cut a little too much off!

Longer wagons, bogie wagons, you just have to get your eye in and do the modification by 'cut and try' on the tightest curve!

What do you lose, apart from the obvious 'not in original condition'?

Quite simply, uncoupling has to be on straight track. I don't see this as much of a problem, but best to be aware beforehand.

muggins
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Re: Could somebody explain the difference between couplings?

Postby muggins » Sat Jul 20, 2019 2:35 pm

Thank you for taking the trouble to do that write-up, Bigmet. Much appreciated!

BTW, I just got myself a Hornby K1, largely as a result of your singing its praises a while back, and I must say I'm really impressed with it. Awesome detail, absolutely looks the part as I remember them, and it runs beautifully on DC.

muggins
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Re: Could somebody explain the difference between couplings?

Postby muggins » Mon Aug 05, 2019 7:00 am

Bigmet wrote: ... Between coaches with close coupling mechanisms a mix of original Roco and Hornby long shank Roco couplers (fully compatible coupler heads) because the rigid linkage these create means that the gangways are in contact on straight or nearly so track for excellent appearance, and the mechanisms then act correctly to space the coaches out to take curves and restore to gangways in contact on returning to straight track.


I'm still scratching my head about this, so at the risk of me becoming a real PITA, which couplings is it exactly that have this magic property? I ask because at the moment it's the big gap that's put me off acquiring gangwayed stock. Minimum radius here is 30" apart from some Peco "short" points in the fiddle yard, two of which are back-to-back, forming a reverse curve of sorts.

heda
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Re: Could somebody explain the difference between couplings?

Postby heda » Mon Aug 05, 2019 8:38 am


Bigmet
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Re: Could somebody explain the difference between couplings?

Postby Bigmet » Mon Aug 05, 2019 9:19 am

muggins wrote:
Bigmet wrote: ... Between coaches with close coupling mechanisms a mix of original Roco and Hornby long shank Roco couplers (fully compatible coupler heads) because the rigid linkage these create means that the gangways are in contact on straight or nearly so track for excellent appearance, and the mechanisms then act correctly to space the coaches out to take curves and restore to gangways in contact on returning to straight track.


... which couplings is it exactly that have this magic property...


This is all a little involved so have a quiet moment to take it in.

The principle on which the close coupling works is simple enough, the coupler mount is on a cam track mechanism which pushes the coupler away from the vehicle end when deflected sideways; as when the vehicle is on a curve. These mechanisms will work on any curvature which the vehicle will negotiate uncoupled, your 30" and pair of small rad points will be no trouble.

To actuate the coupled mechanisms between two vehicles the NEM pockets need to be connected by a rigid link. This can be a fixed link or a coupler specifically designed to form a rigid link. Tension locks are useless for this application, and in greater or lesser degree so are other long established model couplers, Simplex, hook and loop, Kadee, etc.. All of these allow pivoting on the coupler head, not what we want.

First rule: the coach has to have NEM coupler pockets. There are plenty of coaches still on sale that predate NEM coupler pocket provision, these are definitely out of scope. (It is possible that some coaches may now have an NEM pocket rigid on a bogie, these too would be out of scope, but I cannot advise as I have not seen such an animal.)

Bachmann's close coupling provision began with BR mk1 and mk2 gangwayed coaches. (I have only had the mk1, so the mk2 is based on what others report.) Bachmann put the coupler head too high and too far inboard (which is a pain).
However, Hornby produce a clone of the Roco 40270 coupler head pattern suitable for close coupling mechanisms, which has a long mount and compensates near perfectly for the Bachmann mispositioning. This is sold in packs as R8220; and Hornby include a pair with their own coaches with close coupling mechanisms.

Bachmann have since then released some gangwayed coaches with correctly positioned coupler pockets: BR mk1 sleepers and mail coaches, Stanier Portholes and Thompsons.
Then there are Hornby's coaches, which with a few early Pullman releases excepted, have the coupler pockets correctly positioned.
For these I use the 40270 Roco type: probably best bought in a bulk pack sold as 40271, unless you have very few coaches to fit.

I wouldn't describe the Roco coupler as an 'autocoupler' it's more of a 'needs help to couple up coupler'. Once coupled it stays coupled however, and has the added convenience of being 'lift out' for uncoupling if manually crane shunting in a fiddle yard. There are other suitable couplers from HO manufacturers, and the Fleischmann 'Profi' comes well recommended, however I have not used it - nor even seen it used - on UK models.

Bachmann pack a fixed rigid link (mouldings of the hoses) with their coaches also. These can be used for semi-permanent coupling. They space the coaches off too far, but as they are moulded in thermoplastic a little work with a hot air gun will quickly reset them to give ideal spacing.

There are 'wrinkles' to know about, and I don't know them all, only those applicable to the coach types I use. So these are the ones I know:
Universal. The coaches need to be free rolling.
Universal. Check the mechanism moves freely. I add a little graphite powder as insurance.
Universal. Ensure gangway end is vertical, flat and smooth, so it will not catch as it separates from and restores to contact. Add a little graphite powder on the faceplates too.
Universal. The mechanism manufacture is not closely toleranced. I adjust as required on the pocket to have the gangway faceplates just in contact on straight track.
Bachmann mk 1. Often needs a little shaved off the bottom of the buffer beam to clear the coupler for free movement.
Hornby. Retract sprung buffers. (A little piece of wire insulation over the rear of the buffer shaft does this and is fully reversible)
Hornby Pullmans. Remove gangway end covers.
Height mismatch when coupling Bachmann to Hornby. I find I get away with it! (No big bumps on the layout basically, there is a location in a goods yard which can cause an uncouple but it is pretty extreme and awaits rebuilding, it wouldn't be tolerated on a running line.)
For autocoupling I fit each end of a train formation with Kadee. Actually moving to body mounting the Kadees in the buffer beam, but that is another story.

The neat stuff.
Your gangwayed train looks really well on straight or very slightly curved track. You can go further with sprung gangway connector conversions if you wish.
The train moves properly as one piece, no picking up one at a time. A heavy load often makes steam locos do a realistic half turn or two of wheelslip when getting away, which looks very good.
After a few years operation you can see by polishing on the gangway face plates where the buffing action occurs.

muggins
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Re: Could somebody explain the difference between couplings?

Postby muggins » Mon Aug 05, 2019 1:26 pm

Brilliant stuff Bigmet, so thank you yet again.

Seeing as how there's so much really useful stuff in this thread, which must be of interest sooner or later to just about everybody with a 00 railway, can it perhaps be made a sticky, or the key posts be incorporated as a website article somehow?

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pete12345
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Re: Could somebody explain the difference between couplings?

Postby pete12345 » Wed Oct 23, 2019 2:05 pm

I've experimented with the Keen Systems units before for close-coupling older stock. Really they are intended for use between coaches for semi-permanent rakes of stock, and in this application they work well. It's possible to adapt them for use with NEM 362 couplers but as mentioned above they need to be a rigid link for the mechanism to function. So not worth fitting them at the ends of the train unless you're using something other than tension-lock couplings.

Fleischmann make a similar conversion mechanism which could be made to work. It comes with their close coupling heads attached so ideally you'd be using that system for the rest of the layout too. It's similar to Kadee in that it allows for remote uncoupling and pushing uncoupled wagons without recoupling.

Disregard any mention of NEM couplings on older UK stock, particularly Bachmann. They fitted the coupler pocket, but usually at completely the wrong position so you can't simply exchange couplings. This entirely negates the reason for fitting them and they needn't have bothered. It was alway a bit of a minefield finding stock that actually meets the standard.
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