Replacing couplings on Hornby coaches

[TW1306]

(Firstly I should say that I'm an absolute beginner with railway modelling, so please excuse me if I say something silly 😁)

 

In the interest of starting a proper layout I recently dug out a couple of 00 gauge locos and stock that I got about a decade ago, and noticed that the tension-lock couplings on the Hornby coaches I have are a lot larger than those on a Bachmann loco I'd like to run with them; furthermore the Hornby couplings are held in place on the bogies by a clip, while the Bachmann ones use NEM pockets. Is it worth attempting to replace the larger ones with the smaller Bachmann pockets? It'd involve removing a fair bit of plastic from the bogies and attaching the pockets to them somehow - this would also be the first 'DIY' modelling project I've ever done.

[DCB]

Hornby coaches are a right old hotch potch of left overs from now defunct manufacturer's ranges.   Yours sound like ex Airfix which came with much neater tension locks  than Hornby fitted and the Airfix tension locks clip int the same clips as a direct replacement.    Older ones from when Triang/Hornby dropped the Triang Prefix were nice pressed tin couplings normally attached with rivets to coaches and screws to locomotives.  They give excess spacing but the height can be adjusted.  I sift these back on the bogie to reduce the gap between coaches.   Then they made the coupling integral with the bogie, Nasty "Superseal" metal rim plastic wheels which are tight to gauge.   You can turn the bogie round and fit a coupling to the back end but lie's too short.  The latest we have have the coupling on the body not the bogie which have their own infuriating peculiarities.  I treat Hornby like an aid to scratch building or a display cabinet model rather than an actual ready to run on a layout model.

[frobisher]

2 hours ago, TW1306 said:

furthermore the Hornby couplings are held in place on the bogies by a clip, while the Bachmann ones use NEM pockets.

 

What you want is likely Hornby's "R8099 Coupling Assemblies (Pack 10)" which are the narrow variant of this old Airfix type coupling.

[The Johnster]

Replacing older types of tension lock couplings with modern types that can fit into NEM pockets is a good idea if the work is within your comfort zone is probably a good idea.  For wagons you can use the Parkside PA14 mounting blocks, basically the dovetail piece that the 'waggler' on the coupling fits into.  It is made of quite soft plastic and can be easily trimmed to size or packed to set the couplings with the bar at a standard level (important for reliable operation).  On coaches, bogie wagons, or locos, things are a bit harder and some bodgery will have to be undertaken.  I find the best way is to simply superglue the rear face of the waggler to the bogie cross member or a suitable place on the loco; you might have to provide an L shaped bracket for it to glue to.  It is important to preserve the function of the waggler as it gives the coupling the sideplay it needs, especially on sharper setrack type curves.  Note that my layout is a fairly small BLT, loads are light, speeds low, and accelleration gentle, and this 'glue it to something' method may not be sufficient for heavy haul main line work...

 

Practice on old vehicles first until you develop a method that works for you.  The main things to watch for are bar height, to an extent it doesn't matter what this is so long as it conforms to a layout standard, and the distance the coupling is set proud of the buffer beam with regard to your minimum curvature and the length of the buffers.  Buffers should not touch more than the lightest possible 'kiss' on your tightest curvature when the train is being hauled, or they will push the vehicles off the road, or lock when it is being propelled, and reverse curves will be the controlling factor in this.

 

Welcome to the wonderful world of realistic-looking tension lock couplings, where all is to a standard specification and there are never any problems caused by differences in the material the coupling is made out of, or the bar or hook profile, or the mounting method, and all is sweetness and light.  Yeah, right...

[TW1306]

16 hours ago, frobisher said:

 

What you want is likely Hornby's "R8099 Coupling Assemblies (Pack 10)" which are the narrow variant of this old Airfix type coupling.

Thank you very much for the suggestion! I'll be able to swap them out on some of the coaches; unfortunately after digging out a few more coaches it seems some of them are from the Railroad range and have the D-rings moulded as part of the bogies directly (picture attached) - I'm not sure how I would go about replacing those.

[Bluebell Model Railway]

1 hour ago, TW1306 said:

Thank you very much for the suggestion! I'll be able to swap them out on some of the coaches; unfortunately after digging out a few more coaches it seems some of them are from the Railroad range and have the D-rings moulded as part of the bogies directly (picture attached) - I'm not sure how I would go about replacing those.

See if these guys can help: mademe.co.uk/shop/vectis-3d-models/

Edited July 19, 2022 by Bluebell Model Railway

[The Johnster]

23 hours ago, TW1306 said:

Thank you very much for the suggestion! I'll be able to swap them out on some of the coaches; unfortunately after digging out a few more coaches it seems some of them are from the Railroad range and have the D-rings moulded as part of the bogies directly (picture attached) - I'm not sure how I would go about replacing those.

You’d need to remove the coupling, fretsaw or junior hacksaw, and superglue the rear face of the replacement NEM box’s waggler direct to the centre of the face of the bogie where you’ve cut the old coupling away, so the surface needs to be dressed and prepared.  An alternative method of fixing would be to drill 0.25mm (or smaller if you can) holes in the rear face of the NEM waggler (minidrill) and the centre of the bogie crosspiece, and insert a short length of 0.25mm wire into them, secured by a spot of sperglue.
 

This is a better solution in engineering terms, less of a bodge and stronger, but requires great care when drilling the waggler; hole must be dead central, dead straight, and probably not more than 1mm deep to preserve the structural integrity of the waggler.  Deep as you like/all the way through on the bogie.
 

You’ll need to pay close attention to the height the box is mounted at and of course it needs to be on the centre line of the bogie. 

 

The advantage is that the NEM coupling is smaller and less intrusive visually that the moulded Hornby monstrosity, and will perform more reliably with your Bachmann loco’s NEM couplings, plus the unsightly and unrealistic gap between the buffers of adjoining vehicles is reduced.  This is limited by your curvature, but as well as looking better can result in getting an extra wagon in for long rakes on sidings; we are all short of space and every little helps…