4mm coupling tests...

[coachmann]

I my other thread discussing fixed couplings for rakes of coaches I mentioned experiments with another type of coupler. Here are the results on Hornby Gresley carriages. I am grateful to Bob Treacher at Alton Model Centre for advice and suggestion to fit a Hornby-Roco type at one end of a coach and a shorter Roco type at the other.

 

I tried two Roco NEM couplings but they brought the coaches too close together and would not couple.

 

Below are the usual tension-lock couplings....

Below is the Bachmann fixed coupling bringing coach slightly closer together. As they will not uncouple, a fixed formation is difficult to manhandle....

Below is a Hornby-Roco coupled to a Hornby-Roco giving the same distance as the fixed Bachmann....

Below is a Hornby-Roco coupled to a shorter Roco....

Below is the end view of a coach with Roco coupling. The couplings will still auto couple when pushed together and auto uncouple on ramps.

 

What do others think?

[Oldddudders]

As I have recently posted elsewhere on here, I find Hornby Maunsells with Kadee #18s to be very good for close-coupling, although uncoupling is less easy. I have propelled a rake of 6 over long distances, probably 25 feet, without any issues, which I regard as remarkable given the scale-ish appearance of the rake. If you are not going to use magnets, it is possible to lop off the curly bit below the Kadee to enhance appearance, but you do need to have assured yourself that you have a Plan B for uncoupling, which is trickier to do with corridor connectors so close above. My probable solution is, given the fixed sets that Southern used, to not worry about splitting within sets, but put the slightly longer #19 Kadees on either end, ensuring the uncoupling will be easier, whether coupled to another coach or a loco.

 

Frankly Larry, I think Kadees, with their passing resemblance to a buckeye, look better than any of the solutions in the pics you have provided.

[coachmann]

Thanks olddudders, do the Kaydee's you mentioned fit in the NEM socket or are you slotting them into the buffer planks?

 

Larry

[34theletterbetweenB&D]

Within fixed formations I use a pair of the Roco pattern on Hornby for best close coupling, it is usually possible to manually 'bonk' them together firmly enough for a couple; although that may not work with the bellows gangway you have fitted. One can always lift the ends, turn the bogies to get the couplers to extend, and couple them that way if they prove stubborn. (Between Bachmann coaches either a pair of the Hornby or a Hornby-Roco combination to get the closest possible coupling.) As you observe it makes life a lot easier than using the Bachmann 'hoses' link which I used to reform thermally to give the same close coupling. Either end of a fixed formation a Kadee for the excellent auto coupling performance. There's no problem propelling a full size train over any distance, and through any formation of Peco medium or large radius points, although it is advisable to retract the Hornby coaches sprung buffers, and take the gangway covers off Hornby's Pullmans as these have projections which can latch.

 

 

[Theakerr]

I am running short Roco to short Roco with no problems except getting them initially coupled. Takes a vigourous HoG thump. Went with Roco because they were much much cheaper than Kadee. I run fixed rake sets and when painted matt black they dont look to bad. Will probably eventually replace them with the Tony Wright hook and loop method but there is only so much time. Since i allready had them I have used the Roco shorts on a fixed rake of iron ore wagons. Look about as bad as the tension lock but does bring the waggons much closer together.

[Bernard Lamb]

I use a combination of Roco and Hornby compatible types with Modellers Mecca or home made equivalents to fill in any gaps. I prefer a longer than prototype gap as a last resort but with an infill rather than leave an open gap between coaches.

Bernard

[MEGair]

Hi,

 

I have a rake of Red & Cream Hornby Gresleys, which I fitted the Hornby-Roco style close couplers. I was not really happy as I found that the gap was closer, but not enough. I found that if I fitted Kaddee no18 couplers this brought them together where there was only a slight gap. Very happy with the result. No 19s are a bit longer if you need them to go round tighter radius. My rake of coaches run as that, a rake.

 

see photo

 

Mark

 

[BR60103]

Larry: Kadee #s 17, 18, 19 and 20 have NEM shanks. 17 is shortest, 20 is longest.

I would leave the uncoupling pins on as any other manual uncoupling method usually means sticking something down between the corridor connections. You can use a pointed stick to pull the pin over.

[Oldddudders]

Larry: Kadee #s 17, 18, 19 and 20 have NEM shanks. 17 is shortest, 20 is longest.

I would leave the uncoupling pins on as any other manual uncoupling method usually means sticking something down between the corridor connections. You can use a pointed stick to pull the pin over.

Exactly right. The only vaguely tricky bit is using long-nose pliers to pinch the Hornby couplings to remove them! By the third vehicle of a batch, it's dead easy!

 

I wouldn't argue at all about leaving the coupler trip pins on - it's just that some folks feel the loss of magnetic pull is less troublesome than the unscale effect of the pins!

 

Kadee do sell a plastic pointed stick as David mentions - but I'm not completely convinced it is feasible to use it in a UK station platform. Most US modellers run far more freight cars than "varnish" (passenger coaches) and uncoupling in a yard will always be easier than in a platform.

 

Also glad that Gresleys perform as well as Maunsells in the close-coupling stakes!

[coachmann]

Also glad that Gresleys perform as well as Maunsells in the close-coupling stakes!

I suspect this is because the NEM socket sits on the Hornby "expansion link" which automatically sets the coaches further apart on curves.

 

If I devise a method of fitting Roco on whitemetal bogies (as on my brass coaches) I'd have to either allow more room for curves or fit spung buffers.

 

Thanks Mark for the advice on Keydee coupling types to fit NEM sockets, those Gresleys do look better. This is another avenue worth exploring. I havent forgotten the 'fixed' Barrie Stevenson coupling either.

 

Cheers,

Larry G.

[Jamie]

Looking at the Howes of Oxford website last night there appears to be a floor-mounted version of the Roco coupling (out of stock) which despite the tiny image would appear to include the spring/extension mechanism.

 

Having got a play with these Roco-style couplings which came with my Stanier fleet (consisting of 1 BG so far!), I plan to adopt them as standard within rakes.

[34theletterbetweenB&D]

I suspect this is because the NEM socket sits on the Hornby "expansion link" which automatically sets the coaches further apart on curves. ...

This expansion link or close coupling mechanism (CCM) is something whch both Hornby and Bachmann are installing in their most recent coaches and elsewhere, yet strangely neither company offers any guidance to their use: and weirder yet the supplied alternative couplings do not fully exploit the potential of the design. It wasn't until I saw a 'Keen Systems' demo at an exhibition some years ago that the penny dropped, specifically about needing a coupler which formed a rigid bar to work the CCM efficiently.

 

The strangest situation is on Hornby's all new diesel types (30/31, 50, 56, 60) where CCM is fitted, despite the fact that these are primarily freight machines, and liitle appropriate freight stock is similarly equipped. Then they roll out the new HST, a dedicated passenger locomotive with corridor connector: no CCM, just where it would have been most appropriate!

[frobisher]

This expansion link or close coupling mechanism (CCM) is something whch both Hornby and Bachmann are installing in their most recent coaches and elsewhere, yet strangely neither company offers any guidance to their use: and weirder yet the supplied alternative couplings do not fully exploit the potential of the design. It wasn't until I saw a 'Keen Systems' demo at an exhibition some years ago that the penny dropped, specifically about needing a coupler which formed a rigid bar to work the CCM efficiently.

 

This is one reason that the Bachmann EZ Mate NEM couplings work better than the Kadee #20s on the (NEM pocket far too far back) Bachmann MK2s. The head doesn't swivel so giving a more rigid arrangement at "full stretch" so that they can actually couple without direct HoG involvement. Shame these only come in "Loooong" as they would overall be better for semi-fixed rakes than the Kadees.

 

The strangest situation is on Hornby's all new diesel types (30/31, 50, 56, 60) where CCM is fitted, despite the fact that these are primarily freight machines, and liitle appropriate freight stock is similarly equipped. Then they roll out the new HST, a dedicated passenger locomotive with corridor connector: no CCM, just where it would have been most appropriate!

 

Yup, somewhat disappointing that, though I think I understand why they did it that way (the MK3 DVT similarly has no CCM). In a nutshell, the Hornby MK3s don't have a CCM and the bogie mounted coupling has quite a bit of swing in it which would try the patience of most CCMs I think. There's also the two air tanks sitting exactly where the CCM would have to on the HST. This shouldn't have been an insurmountable problem (supply two sets of air tanks, one fully detailed as currently fitted, and the other cosmetic sides to sit around the CCM for normal usage).

 

I'd disagree somewhat with the 50 being primarily a freight machine rather emphatically

[JZ]

I use NEM Kadees of various lengths on my Maunsell's, Gresley's and Pullmans, although I still use the Bachmann fixed type on my Mk1s despite being a pain in the backside on longer rakes, my maximum is 9. Yet to find something suitable for my Hornby Stanier's, mainly due to the withdrawn type gangways.

[Adrian Wintle]

I have found that, for fixed rakes, the Roco coupling or the Fleischmann Profi coupling (same length, but not compatible with the Roco) work fine in the Hornby Maunsells and Gresleys. You do have to wiggle the bogies slightly to get the couplers to engage properly, but after that the rake works fine (minimum curve on the layout is about 30") The geometry of the Staniers is such that they need a Hornby/Roco combination to prevent buffer lock.

 

The difficulty with using Kadees in the close-coupling mechanisms is that these mechanisms work best with a coupling that approximates a solid bar. It is the stiffness of the coupler that re-centres the mechanism under load (the spring only does it without load), so any coupler with lateral (tension lock) or rotational (Kadee) freedom can cause running problems with a significant tail load. This is because the coupling mechanism will extend due to the tail load (since the coupler isn't keeping it centred) which can cause the bogies to run skewed. This puts one leading flange hard against the rail head where it can climb a track gap or similar imperfection. This typically causes the leading bogie of the second coach to derail (as the first-second is the coupling with the most unconstrained tail load). This doesn't tend to cause problems until the train length is more than 5 coaches, and is more of a problem on coaches with relatively short wheelbase bogies and which have a fairly close relationship between the coupler arm movement and the bogie movement (e.g. Hornby Gresleys). Coaches like the Bachmann Mk1s are less prone to derailments because, even though the same effect is happening, the bogies don't skew as much.

 

If you want to add close coupling mechanisms to coaches, Roco make two types that have NEM pockets, and Fleischmann makes one that uses a different NEM connection (the same one that Vi Trains has used). The difficulty I have with the Roco ones is that their geometry is such that they only work on coaches with a fairly long overhang (e.g. Mk3) - otherwise they foul the wheels. The Fleischmann mechanism is smaller (and much more fragile), so it can be fit onto more types of stock. You can get Roco couplings with the correct type of tail to fit this (the height-adjustable NEM ones), but it rapily gets expensive since the Fleischmann units cost significantly more than the Roco units even before you buy the Roco couplers (if you use Profis you can save that expense).

 

Adrian

[coachmann]

I came to the conclusion that as my trains of coaches will not be split, I should at least experiment with proper screw type couplings. To this end, a length of track of around 32 " radius was laid on the workbench so experiments could be carried out with coaches fitted with scale couplings and anti-buffer-lock wire between the buffers.

 

Results with screw couplings on the suburbans were not encouraging. Coupling spring tension had to be eased on one coach (LNWR long buffers), and the rake of coach pushed and pulled over the reverse curves. Coaches still tilted and derailed too often to be absolutely failsafe so Bachmanns might be put back on the Suburbans.

 

Roco couplings on the Gresley coaches worked failtlessly although one coupling/NEM socket had to be heat-welded directly to one Gresley bogie by turning the bogie back to front. Without sideplay it shouldnt have worked, but so long as an adjacent coach has a swivelling bar it's okay. Another thing I found was the bow-ended Gresley coaches perfomed better with a little more space between them and so some of the Roco couplings had to be replaced with the slightly longer Hornby-Roco.

 

Larry

[coachmann]

Testing couplings and patience!

 

[Buhar]

My couplings are Dinghams but I'm looking to another solution within rakes of coaches so this thread is really useful. Question, what are the disadvantages of fitting these various couplings under the headstock rather than to the bogie?

[coachmann]

Question, what are the disadvantages of fitting these various couplings under the headstock rather than to the bogie?

If you are referring to the Hornby arrangement, it works fine as it allows the Roco couplings to swing left and right.

 

Roco couplings require to swing right and left like Peco and Kaydee couplings. It is usual to fit such couplings to bogies rather than headstocks if one has sharp curves. The Kaydee is designed for North American stock where there are no side buffers. Where buffers are present as in the UK, they will come together on sharp curves and so the Kaydee's have to have long shanks to prevent buffer-locking.

[Dave Holt]

If you are referring to the Hornby arrangement, it works fine as it allows the Roco couplings to swing left and right.

 

Roco couplings require to swing right and left like Peco and Kaydee couplings. It is usual to fit such couplings to bogies rather than headstocks if one has sharp curves. The Kaydee is designed for North American stock where there are no side buffers. Where buffers are present as in the UK, they will come together on sharp curves and so the Kaydee's have to have long shanks to prevent buffer-locking.

 

Larry,

 

An interesting discussion subject. Tight curves are bound to cause issues with couplings/buffers but are generally unavoidable for most of us (end-to-end single track branch termini excepted!). I would suggest that the extending type coupling fitted to (say) Bachman Mk1's and also supplied by Keen are a good compromise, allowing fairly close coupling on straights and extending to avoid buffer contact on sharp curves. Being body/chassis mounted rather bogie mounted gives a better side-on appearance. Don't forget that Gresleys and other Buckeye fitted stock had the buffers retracted so the whole buffing force was taken by the coupling and the buffer heads do not touch, even on curves.

For end of rake coaches and those fitted with screw couplings, sprung buffers help prevent derailments on curves.

For the push-pull coaches you made, I've used couplings (Masokits) which give scale spacing with the buffer heads touching. To avoid problems on even gentle curves, I found I had to replace the rigid buffers with sprung versions.

 

Dave.

[coachmann]

Dave,

 

I've left the extending type on the Hornby Gresley coaches and slipped Roco type in the NEM sockets. Work fine on my test track of 32" rad with reverse curve. However, I've backtracked to Bachmann for all other stock. If I were using P4 track and associated standards then yes, I'd have to adopt screw and 3-link to keep up appearances. Perhaps fortunately, I have to use 36" radius in places so any pretence at fine scale is quite literally out the door.........Thats where the 36" radius curves are, not in the shed!

 

Larry

[westie7]

Looking at the Howes of Oxford website last night there appears to be a floor-mounted version of the Roco coupling (out of stock) which despite the tiny image would appear to include the spring/extension mechanism.

 

Having got a play with these Roco-style couplings which came with my Stanier fleet (consisting of 1 BG so far!), I plan to adopt them as standard within rakes.

 

Would that be the Roco NEM pocket on a sprung arm?

If so I've crafted these onto coaches previously.. see http://www.clyde-iron.fotopic.net/c1181993.html for details

 

Rgds

Mark

[Adrian Wintle]

Would that be the Roco NEM pocket on a sprung arm?

If so I've crafted these onto coaches previously.. see http://www.clyde-iron.fotopic.net/c1181993.html for details

 

Rgds

Mark

 

I've done the same thing. I notice that your example is on a Mk3 coach, one of the few UK-outline coaches this system actually fits sensibly.

 

Adrian

[westie7]

I've done the same thing. I notice that your example is on a Mk3 coach, one of the few UK-outline coaches this system actually fits sensibly.

 

Adrian

 

I did get it to fit on a Mk2d, with a fair bit of shaving, trimming etc. Never did try the smaller version designed for body lengths of less than 140mm, although much smaller it may operate reasonably well.

 

Mark

[Adrian Wintle]

I did get it to fit on a Mk2d, with a fair bit of shaving, trimming etc. Never did try the smaller version designed for body lengths of less than 140mm, although much smaller it may operate reasonably well.

 

Mark

 

I've played with both sizes. The main problem with both is that the mechanism fouls the wheels unless there is significant overhang (coach length beyond the bogies) or unless you are prepared to compromise on coupler height (i.e. mount the mechanism such that the NEM pocket is above the NEM standard height - with the attendant difficulties in interoperability this brings).

 

The short body length version is narrower (therefore having less range of swing), but is otherwise similar in size.

 

These mechs do work quite well on LWB 4-wheel stock (CCTs etc).

 

Mounting them (and the Fleischmann ones) on my Mk3 fleet has meant that my HSTs all reliably run with the gangways touching on the straights.

 

Adrian