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Discussion Starter · #1 ·
Hi. The coupling mountings on both my Heljan Hymek and class 47 are very "floppy" resulting in the couplings hanging too low. Hymek is worse. Any easy way of ensuring mounts/couplings are horizontal (without having to take bogies off etc). Both locos otherwise perform very well indeed.
Thanks.
 

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QUOTE (34030 Watersmeet @ 6 Nov 2008, 22:43) <{POST_SNAPBACK}>The coupling mountings on both my Heljan Hymek and class 47 are very "floppy" resulting in the couplings hanging too low. ..
The floppiness mainly originates from slack in the pivot for the NEM pocket. On the Heljan loco I have seen it is probably necessary to have the bogie out of the chassis to reduce this slack, because the pivot is positioned a fair way under the loco, and close to the underside of the frame. The owner of the loco didn't fancy that, and settled for a shim of plasticard under the coupler tails in the pocket, secured with cyano, to give the coupler a slight upward set to compensate for the droop at the pivot. The other alternatives for an in-situ fix that I could see were: if you are happy to have the coupler mounting moving as a piece with the bogie frame, try a drop of cyano on the pivot, holding the coupler mount in the required position until the cyano has gone off; or, use a piece of wire formed into paper staple shape as a support to raise the coupler mount, the legs of the staple going into holes in the underside of the frame.
 

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Discussion Starter · #3 ·
QUOTE (34C @ 7 Nov 2008, 13:21) <{POST_SNAPBACK}>The floppiness mainly originates from slack in the pivot for the NEM pocket. On the Heljan loco I have seen it is probably necessary to have the bogie out of the chassis to reduce this slack, because the pivot is positioned a fair way under the loco, and close to the underside of the frame. The owner of the loco didn't fancy that, and settled for a shim of plasticard under the coupler tails in the pocket, secured with cyano, to give the coupler a slight upward set to compensate for the droop at the pivot. The other alternatives for an in-situ fix that I could see were: if you are happy to have the coupler mounting moving as a piece with the bogie frame, try a drop of cyano on the pivot, holding the coupler mount in the required position until the cyano has gone off; or, use a piece of wire formed into paper staple shape as a support to raise the coupler mount, the legs of the staple going into holes in the underside of the frame.
 

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Discussion Starter · #4 ·
Thanks very much for that. I suppose the best way would be to take the bogies off to get at the coupling pivots - I 'm not sure about disturbing the drive shafts though. I'll try the shim in the nem pocket first though, may be the best alternative. I'll give it a go (got the loco in front of me now). The coupling works ok if "hand coupled" but isn't quite high enough to auto-couple.

Thanks again.
 

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Before you go to all that trouble, I replace all of my Heljan couplings (not just the Hymek!), which have a "dropped" section if you look from the side on, with Bachmann or Hornby "straight" section couplings. This raises them by about 1mm or so which is just right to compensate for the droop.
 

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QUOTE (SRman @ 8 Nov 2008, 00:29) <{POST_SNAPBACK}>Before you go to all that trouble, I replace all of my Heljan couplings (not just the Hymek!), which have a "dropped" section if you look from the side on, with Bachmann or Hornby "straight" section couplings. This raises them by about 1mm or so which is just right to compensate for the droop.
Forgotten abuut that. On the example I had to tinker with, substituting the straight coupling wasn't enough. One end in particular the pocket pivot was very slack indeed. My inclination was to take it to pieces and fix the problem at source, but the owner preferred the bodge. As in all manufactured items there is sample variation, and some will require more intervention than others.
 

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Absolutely true, of course, 34C.


My bodge will fix many but not all Heljan products. As an aside, I also found it necessary to do the same with the Dogfish wagons, although it meant that the nice short Heljan couplings were replaced by slightly longer Bachmann / Hornby ones which gave a larger gap between wagons - not very desirable! For the locomotives the coupling length doesn't seem to be an issue.
 

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Discussion Starter · #8 ·
QUOTE (SRman @ 8 Nov 2008, 10:13) <{POST_SNAPBACK}>Absolutely true, of course, 34C.


My bodge will fix many but not all Heljan products. As an aside, I also found it necessary to do the same with the Dogfish wagons, although it meant that the nice short Heljan couplings were replaced by slightly longer Bachmann / Hornby ones which gave a larger gap between wagons - not very desirable! For the locomotives the coupling length doesn't seem to be an issue.
 

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Discussion Starter · #9 ·
Thanks for the comment about using Bachmann or Hornby nem couplings. I've got a packet of spare ones in the loft so I can give that a try. However, what I've done so far with the existing couplings is:

There are two horizontal plastic prongs molded on the front of the bogie moulding between/in front of the leading wheels.
There is a peg moulded on the underneath of the pivoted bar that the nem socket is on the end of. This peg fits between the two prongs which give some springing to centre the coupling bar.

I used a bit of superglue to secure the peg to the prongs, thus holding the coupling bar at the right level. One end stuck ok but the other end didn't stick to the slippery plastic of the prongs, however, the superglue formed a collar which rests on the prongs still holding the coupling up.

My next plan was to fit a bit of tubing (like wire insulation) over the peg to rest on the prongs. That's if the superglue doesn't hold when the loco is being used.

However, using another make of coupling may actually be the next stage.

Thanks to both for all the advice.
 

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I had the same problem with my Hymeks and 47s but not the Westerns curiously.

Above comments seem to have covered the solutions though I would say that the smaller Hornby couplings were the best replacements for the Hymek and seem more compatible with rolling stock and seem to extend the gap between loco and train only a little.

I'm going to give the plasticard idea a try.
 

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Two other possible options:-

1. Place either a 12BA washer over the round pivot or
2. Put a 25mm long piece of plastic tube, such as the insulation from 30 amp cable, over the round pivot.

Personally I usually find changing the Heljan couplings for Bachmann or Hornby works in most, but not all, cases. I noticed that when comparing a Heljan coupling with a Bachmann unit the Heljan plastic that fits the NEM pocket is a thinner plastic and the thicker Bachmann unit cures the coupling droop. If not try options 1 or 2 above.
 

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Ten years after the original post! Now that Heljan have latterly made several models that suit my interest ('Pilot scheme' designs all, BTH and NBL type 1s, BRCW and EE type 2s) I have
found that the 'use a straight Bachmann type' is the best plan for tension locks on the type 1s. The type 2s are exclusively in use on suburban turns, and the screw coupler supplied has
proved good for the relatively short train formations involved, and of course looks very well.
 

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Discussion Starter · #14 ·
10 years! Good grief! A lot has happened since then, I've retired, got 2 grand children, etc. - but Hymek and 47s are still running fine! Couplings have stayed level after tweak.

Like 34c I've also used the screw couplings on type 2s (baby Deltic especially) which work very well on shorter trains. I managed to set the baby Deltic up so that the inner buffers just start to compress on curves - (they are very softly sprung) but fortunately have 30" min radius on the loft layout.
Works well with freight stock with 3 link couplings. I also have a couple of trucks and vans where I just took the tension lock off one end and used the coupling hook with the loco screw link coupling. Then the rest of the train couples to the tension lock at the other end of the leading wagon.

I also superglued a loop of thin wire (handrail wire) to the hook on a tension lock coupling on one coach so that it would drop onto the loco scale coupling hook. The rest of the train then couples to the leading coach or wagon using the normal couplers.

This also worked well with Dapol Westerns where a tension lock coupler would stick through the front valence. The scale coupling hook seems up to pulling quite a few Mk1s this way.
 

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I do find it amusing that the troublesome trio of BoBo pilot scheme locos that Heljan have offered, all have such good models. The NBL type 1 and EE type 2 'Baby Deltic' are really fine,
and the EE type 2 may well be the most powerful loco on the layout when it comes to haulage! (All so unlike reality, and then Bachmann have the rattlecan Cravens DMU and Hornby
the 'concrete mixer' Thompson L1 2-6-4T, each notorious in its own way on KX suburban, but very good models all around. Dapol have yet to join the party with their long promised
NBL DE type 2 now running close to ten years since announcement. The prototype was designed, constructed, commissioned into service and banished from KX in half the time...)

Never having had a Dapol diesel model to really look at, I wonder what the NEM pocket positioning is like on their product? Unless Dapol include a good screwlink coupler representation
that is usable I will probably filch a couple from the Heljan type 1s and use these, as this loco is for (brief use on) inner suburban traffic only.
 

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Discussion Starter · #16 ·
If I can remember how I posted pics before (if my Flickr account is still there!) I'll try and post a pic of the 52 class screw link couplings that come with the Dapol model. Agree about the Heljan bo-bo locos.
 

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Dapol coupling for class 52 compared to 3 link and screw link couplings. Can't remember the other makes. (Smith?)



Dapol class 52 coupling on hook plus another.



Heljan Baby Deltic using scale loco coupling



On curve, loco buffer (just) compressing.
 

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We so need some engineering genius to come up with a fully automatic looks-exactly-like-a-scale-three/screw-link coupler don't we? For less than 5p a shot of course.
 

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*** LOL - maybe soon to part 1, but definitely not to part 2 :)

regards

Richard
 

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Discussion Starter · #20 ·
Here's my, well, 1 link coupling. Definitely less than 5p a shot.



Wire loop superglued to tension lock hook. The advantage is that the coupling can still couple to other tension lock couplings if needed, with the loop in place. It will haul a long train.



It just drops onto the loco coupling hook. This avoids having a tension lock coupler on the loco while other stock with ordinary coaches can still be coupled behind. I did this really for the Western as that doesn't look good with tension lock couplings as they have to stick through a hole in the front valence,
A friend with a coarse scale O gauge layout had couplings that worked somewhat like this with a pivoted punched metal link that dropped onto the coupling hook on the next vehicle.
 
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