Preferred height for Kadee couplers on UK 4mm scale models

[Dunsignalling]

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 ?

When I started using Kadees that way in the early-mid nineties, I seldom encountered other users.

 

However, they have become much more widespread in recent years.

 

I rarely attend an exhibition of any size these days without seeing at least one UK-outline layout using Kadees and photographs featuring them have been showing up in many (if not most) issues of the mainstream modelling magazines for several years.

 

How many people use them without any public exposure is, of course, anybody's guess.

 

John

Edited June 11, 2013 by Dunsignalling

[47137]

Logically the sideways play ought to be a problem but like John I could not point a finger at it. I suspect most modern 00 wheels are as good as the wheels on the HO models the Kadees are designed to work with, and this means "good enough". One way to find out would be to set up a vehicle with some old fashioned coarse Tri-ang wheels and see what happens ... but these wheels won't go through modern pointwork and maybe hit the sleepers too. Perhaps a good practice would be to require a wheel back to back of 14.5 mm for 00, and replace wheels which won't meet this standard.

When my Kadees fail to couple it seems to be because the wheels on the loose wagons are too free running, and they just trundle away!

[298]

Logically the sideways play ought to be a problem but like John I could not point a finger at it. I suspect most modern 00 wheels are as good as the wheels on the HO models the Kadees are designed to work with, and this means "good enough".

 

When my Kadees fail to couple it seems to be because the wheels on the loose wagons are too free running, and they just trundle away!

 

Trust me, RTR manufacturers OO wheels aren't a patch on HO. "Good enough" just doesn't cut it, it's only recently Hornby have supplied something round with their stock. It's true that aftermarket wheels are alot better but we're talking about quick "out of the box and onto the layout" modifications here, right...?

 

You've raised an interesting cornundrum with vehicle weights here, obviously a pair of Kadee's require a certain buffing force to engage, which means the stationary vehicle has to have a certain rolling resistance, given by it's own mass and friction in the wheelsets. Comparing a typical UK wagon to a US one shows the two are completely different, two fixed axles Vs two bogies with closely spaced wheelsets, lightweight but unknown weight Vs agreed standard based on the length of the vehicle, the list goes on. You can therefore conclude that if you were designing a UK spec Kadee coupler, it'd probably be alot different to the US standard.  

[47137]

Trust me, RTR manufacturers OO wheels aren't a patch on HO. "Good enough" just doesn't cut it, it's only recently Hornby have supplied something round with their stock. It's true that aftermarket wheels are alot better but we're talking about quick "out of the box and onto the layout" modifications here, right...?

 

All the locos I have converted have the manufacturer's wheels, and about half of the rolling stock too. The manufacturer's wheels I have kept have worked with Kadees; the converted ones are the remains of a foray into EM gauge rather than problems with the originals. So for me, I do mean 'good enough'; but I realise this is not universal.

 

 

I am describing what has worked for me. I ran three locos and four wagons on a club layout last night and they worked. I am hopeful I have found the level of precision of alignment I need to get the performance I want, but I want many months of use and lots of delayed uncoupling to be confident of this. Nothing I have written has meant to imply a particularly quick conversion. Some vehicles are easier than others, some have needed two or three goes, but practice (especially when it goes wrong) helps a lot. I am averaging about two vehicles per hour.

[br-nse-fan]

Logically the sideways play ought to be a problem but like John I could not point a finger at it. I suspect most modern 00 wheels are as good as the wheels on the HO models the Kadees are designed to work with, and this means "good enough". One way to find out would be to set up a vehicle with some old fashioned coarse Tri-ang wheels and see what happens ... but these wheels won't go through modern pointwork and maybe hit the sleepers too. Perhaps a good practice would be to require a wheel back to back of 14.5 mm for 00, and replace wheels which won't meet this standard.

When my Kadees fail to couple it seems to be because the wheels on the loose wagons are too free running, and they just trundle away!

 

the only coupling hurdle I've encountered thus far (other than height related issues) are when shutting freight cars.  Specifically, the long wheelbase wagons such as Bachmann's VDA and OCA type wagons.  Due to the pivoting axle to help with tight curves, they can sometimes be less than straight, especially when propelling backwards, instead of pulling.

 

Another member on here once commented that fixing the axle so that it does not pivot resolves this issue.

[Ramblin Rich]

It does seem a bit bizarre that we've got to the situation that vehicles are almost 'too' free running to make couplers operate well! I've seen references in onther threads to intoducing a dgree of resisitance back inot the wheels, using small foam pads or spring wire bearing on the axles. I assume the wheels in the US vehicles mentioned in "298's" post ^^^ are free running, just with more weight (& therefore inertia) to make them work well?

[Dunsignalling]

Trust me, RTR manufacturers OO wheels aren't a patch on HO. "Good enough" just doesn't cut it, it's only recently Hornby have supplied something round with their stock. It's true that aftermarket wheels are alot better but we're talking about quick "out of the box and onto the layout" modifications here, right...?

 

You've raised an interesting cornundrum with vehicle weights here, obviously a pair of Kadee's require a certain buffing force to engage, which means the stationary vehicle has to have a certain rolling resistance, given by it's own mass and friction in the wheelsets. Comparing a typical UK wagon to a US one shows the two are completely different, two fixed axles Vs two bogies with closely spaced wheelsets, lightweight but unknown weight Vs agreed standard based on the length of the vehicle, the list goes on. You can therefore conclude that if you were designing a UK spec Kadee coupler, it'd probably be alot different to the US standard.  

Much US r-t-r stock is lighter than the NMRA standard, too and the required buffing force can exceed the resistance of any free-running wagon/car if the Kadee has the #5-style pressed-brass spring inside the draft box (in my case, usually a # 41 or 46). The old #16 coupler, which Kadee promoted as being for UK/European stock had much softer springing. 

 

Both that and the 40-series have been discontinued and the newer Whisker-sprung equivalents have a much lighter action (akin to the older product). These seldom fail to couple first go, even when picking up a single (otherwise standard) wagon. IMHO, their performance negates any requirement for a separate 'UK' Kadee specification. 

 

On my own models, I generally add extra weight to r-t-r wagons and, with 9/10 foot wheelbase stock I aim for 40-45 grams, long wheelbase vans, 60-70 and bogie stock at least 100. A bit lighter than the NMRA standard, but quite adequate empirically. However, consistent mass produces consistent running whatever couplings are in use. In my case it has less to do with overcoming the buffing force than reducing the tendency of vehicles to move under the power of uncoupling magnets acting on their axles!

 

The wheels on the layout I cited as an example are whatever was to hand when the wagons were prepared, old Bachmann with plastic tube axles (now becoming life-expired), newer Bachmann and Hornby, Romford on the Parkside kits and even a few Gibson. The mixture doesn't have any noticeable effect on the way the couplers behave.

 

John

[Dunsignalling]

All the locos I have converted have the manufacturer's wheels, and about half of the rolling stock too. The manufacturer's wheels I have kept have worked with Kadees; the converted ones are the remains of a foray into EM gauge rather than problems with the originals. So for me, I do mean 'good enough'; but I realise this is not universal.

 

 

I am describing what has worked for me. I ran three locos and four wagons on a club layout last night and they worked. I am hopeful I have found the level of precision of alignment I need to get the performance I want, but I want many months of use and lots of delayed uncoupling to be confident of this. Nothing I have written has meant to imply a particularly quick conversion. Some vehicles are easier than others, some have needed two or three goes, but practice (especially when it goes wrong) helps a lot. I am averaging about two vehicles per hour.

My experience is much the same (apart from the EM bit). As you suggest, achieving reliable delayed uncoupling is the best possible confirmation that you are getting it right!

 

I take it your quoted work-rate is for known jobs - on one or two locos I have encountered, it took most of an evening to do one end!

 

John

[47137]

I take it your quoted work-rate is for known jobs - on one or two locos I have encountered, it took most of an evening to do one end!

Thinking about it, I am probably managing nearer two vehicles per evening not per hour. Dapol locos and wagons with NEM pockets have been straightforward to set up, and without these my average would be a lot slower. Tonight I shall assemble some 146s into their boxes, and do something/anything else while they set :-).

[br-nse-fan]

Thinking about it, I am probably managing nearer two vehicles per evening not per hour. Dapol locos and wagons with NEM pockets have been straightforward to set up, and without these my average would be a lot slower. Tonight I shall assemble some 146s into their boxes, and do something/anything else while they set :-).

 

I've found that using a liquid cement works nicely, and quickly.  I've also begun to use the nylon / plastic screws and screwing the coupler to the wagon instead of gluing.  This does a couple things... it allows the coupler to be attached to the wagon while the box is still setting, as the screw holds everything together.  It also allows the coupler to be removed at a later date (if needed) with little to no fuss.

[tender]

Dapol locos and wagons with NEM pockets have been straightforward to set up, and without these my average would be a lot slower.

I find the NEM sockets on Dapol locos droop so much it makes them useless for use with kadee 18,19 or 20 as its not possible to get the height set correctly. On a couple of locos I've glued the socket in place but that make the left/right springing of the socket inoperable but it hasn't affected the performance of the coupler.

 

If I'm reading this thread correctly, are you removing the Dapol NEM socket and replacing it with a kadee box?

[Dunsignalling]

I've found that using a liquid cement works nicely, and quickly.  I've also begun to use the nylon / plastic screws and screwing the coupler to the wagon instead of gluing.  This does a couple things... it allows the coupler to be attached to the wagon while the box is still setting, as the screw holds everything together.  It also allows the coupler to be removed at a later date (if needed) with little to no fuss.

My preferred method (#146) is to glue the box to the wagon then use the nylon screw to secure the lid after tapping a hole in the chassis.

 

This requires the wagon to be dismantled unless you are willing to drill and tap the hole through the steel weight. I replace the steel weight with lead flashing achieve my target weight anyway so it's all become part of a standard routine.

 

John

[47137]

I find the NEM sockets on Dapol locos droop so much it makes them useless for use with kadee 18,19 or 20 as its not possible to get the height set correctly. On a couple of locos I've glued the socket in place but that make the left/right springing of the socket inoperable but it hasn't affected the performance of the coupler.

 

If I'm reading this thread correctly, are you removing the Dapol NEM socket and replacing it with a kadee box?

No. I just plugged in a #18 or #19. Maybe I have been lucky or you have been unlucky. My two wagons and two locos are new or nearly new, so I will find out soon enough if they do sag.

 

The NEM sockets I have removed have been mostly Bachmann ones, but other contributors have suggested removing them all. This does get rid of one third of this marriage of convenience of US coupler, Euro mount and UK stock. The NEM sockets on my two Roco 4-wheel coaches (German prototypes) are engineered differently to all the UK models I have, and have a moulded support bar below the pocket. This would stop any sag, and makes me think of a length of piano wire to lift sagging pockets. I haven't tried this yet. 

 

I want to keep an open mind on using these pockets with Kadees. The "inboard" ones on locos like the Dapol Western, and the rigid ones on bogies on the Bachmann 2-EPB are useful and and (to my mind) an integral part of the model and I wouldn't want to try a conversion to remove them. The thread has shown that only some pockets are downright "wrong", e.g. the Bachmann wagons early on from post number 1, and there are solutions for these with lowered pockets and without them. I have one wagon with its Bachmann pockets held rigid and at the right height by Peco track pins, this seems to work (the Kadee has its own pivot of course) but the pocket is usually on a flexible mount and I am reluctant to recommend it. I think you must take each model on a case by case basis.

[Dunsignalling]

I want to keep an open mind on using these pockets with Kadees. The "inboard" ones on locos like the Dapol Western, and the rigid ones on bogies on the Bachmann 2-EPB are useful and and (to my mind) an integral part of the model and I wouldn't want to try a conversion to remove them. The thread has shown that only some pockets are downright "wrong", e.g. the Bachmann wagons early on from post number 1, and there are solutions for these with lowered pockets and without them. I have one wagon with its Bachmann pockets held rigid and at the right height by Peco track pins, this seems to work (the Kadee has its own pivot of course) but the pocket is usually on a flexible mount and I am reluctant to recommend it. I think you must take each model on a case by case basis.

I definitely agree with this; I don't remove pockets just for the sake of it and would certainly not mess with the Dapol Western. I have done so on the NBL Type 2 (Class 22) because the mounts on mine did droop after a while. Fitting options on locos are more variable than other models but the NEM mounts mean I don't usually have to make snap decisions.

 

On wagons, I certainly prefer 'boxed' Kadees and only retain the NEM mount where I consider removing it would be unduly difficult.

 

I generally run multiple units without couplers on the outer ends and fit Roco heads on the inners. The less flexible nature of these compared with NEM Kadees seems to damp out excess movement between cars as the unit negotiates pointwork.

 

John

Edited June 12, 2013 by Dunsignalling

[tender]

I definitely agree with this; I don't remove pockets just for the sake of it and would certainly not mess with the Dapol Western. I have done so on the NBL Type 2 (Class 22) because the mounts on mine did droop after a while. Fitting options on locos are more variable than other models but the NEM mounts mean I don't usually have to make snap decisions.

 

On wagons, I certainly prefer 'boxed' Kadees and only retain the NEM mount where I consider removing it would be unduly difficult.

 

I generally run multiple units without couplers on the outer ends and fit Roco heads on the inners. The less flexible nature of these compared with NEM Kadees seems to damp out excess movement between cars as the unit negotiates pointwork.

 

John

HI John.

 

What Kadee did you use on the Class 22? I have on of these on my to do list.

[Dunsignalling]

HI John.

 

What Kadee did you use on the Class 22? I have on of these on my to do list.

Hi tender,

 

I used a # 31, fixed to the main chassis with M2 nuts & bolts. The way mine are installed, the draft box protrudes outside the buffer beam but not beyond the bottom corner of the body.  It's not very noticeable, and once I have fitted all the hoses, it should be almost invisible. 

 

The screw-hole that held the NEM mount on is too far inboard to fit a Kadee box directly to it though it might be possible to make an intermediate mounting plate.  

 

If you are not be familiar with the 30-Series (or don't enjoy assembling them), try a # 141 in the optional (shorter) # 252 box. 

 

John.

[tender]

Hi tender,

 

I used a # 31, fixed to the main chassis with M2 nuts & bolts. The way mine are installed, the draft box protrudes outside the buffer beam but not beyond the bottom corner of the body.  It's not very noticeable, and once I have fitted all the hoses, it should be almost invisible. 

 

The screw-hole that held the NEM mount on is too far inboard to fit a Kadee box directly to it though it might be possible to make an intermediate mounting plate.  

 

If you are not be familiar with the 30-Series (or don't enjoy assembling them), try a # 141 in the optional (shorter) # 252 box. 

 

John.

 

Thanks John.

 

I think i have a few Series 30 couplings, not sure if it's the #31 though, i'll check when i get home. Like you say they are a bit fiddly to put together.

I'll try and pick up some #141's this weekend at Wigan. No harm  in having a few alternatives.

 

Ray.

[47137]

Some contributors to this discussion have asked how many UK modellers use Kadee couplers and I asked Kadee how many they sell in the UK. The answer to the question remains an unknown, but their response does give me a fresh idea, which goes back to the title of the thread ...

I asked:

"I have started an interesting discussion at www.rmweb.co.uk entitled "Preferred height for Kadee couplers on UK 4mm scale models", there have been over sixty messages so far. The contributors agree the best height is the HO height (25/64"), and there is a lot of constructive input about how to modify UK ready to run models to fit Kadees. There is one nagging question: "what proportion of UK modellers use Kadee couplers?" If (for example) you could tell me how many couplers you sell in the UK each year, I could offer this to the forum and we could try some arithmetic, for example suppose a total of 50 wagons and locos per average user, then estimate the number of users. I believe all Kadee installations on UK models are done by modellers themselves, there is no ready to run equipment already fitted. Regards etc"

And Kadee replied:
"Very interesting and informative discussion you started. We have to deal with the coupler height difference between HO scale (25/64" 9.9 mm ) and OO scale (29/64" 12 mm) especially using the NEM coupler pockets.

We have no way of measuring the market share for the UK or anywhere else. Even if we could we'd keep that info to ourselves as proprietary info. As far as our sales lines up it goes about like this, USA/Canada is the largest of course, the UK and Australia are about even, mainland Europe next, then the rest of the world has the last share of our sales.

We do find that most of the modelers we help from the UK with coupler conversions are individuals and not shops or clubs.

We do sell to certain manufactures that use our couplers on their models. ExactRail, Intermoutain, BLMA, Tangent, MTH, (some) Broadway Limited, and various others (smaller)".

 

- - - 

I had not read about the 29/64” / 12 mm height for 00, but I get the feeling most 00 modellers who use Kadees as general-purpose couplers (meaning as a resource, not within a fixed rake) try to put them at the HO height of 25/64” / 9.9 mm. I think I have learnt at least four reasons for this in this thread: to fit below UK buffer beams; to work with NEM pockets; to use delayed uncoupling; to use the HO standard. I wonder ... should we ask Kadee to set their recommended height for 00 to match their standard for HO?

 

As I paste in this text, I am wondering, by ‘00’ do they mean ‘American 00’, but I think this is worth sharing.

 

 

[298]

You'd get a better idea of use on UK layouts by discretely surveying exhibition layouts at shows, asking Kadee how many they sell will include figures for US layouts where they are considered to be the standard.

[Pacific231G]

And Kadee replied:

"Very interesting and informative discussion you started. We have to deal with the coupler height difference between HO scale (25/64" 9.9 mm ) and OO scale (29/64" 12 mm) especially using the NEM coupler pockets.

- - - 

 

I had not read about the 29/64” / 12 mm height for 00, but I get the feeling most 00 modellers who use Kadees as general-purpose couplers (meaning as a resource, not within a fixed rake) try to put them at the HO height of 25/64” / 9.9 mm. I think I have learnt at least four reasons for this in this thread: to fit below UK buffer beams; to work with NEM pockets; to use delayed uncoupling; to use the HO standard. I wonder ... should we ask Kadee to set their recommended height for 00 to match their standard for HO?

 

As I paste in this text, I am wondering, by ‘00’ do they mean ‘American 00’, but I think this is worth sharing.

 

 

I doubt if they mean American 00 (4mm/ft scale 19mm gauge) as it's very little used. The 9.9mm height in H0 scale correspond to 34 inches which is (just) within the US regulation height for the centre of couplers. The 12mm height Kadee mention for 00 is a bit odd as it's way too high for the American regulation coupler height of 31.5-34.5 inches when scaled for 4mm/ft but far too low for the 997mm height of Buckeye coupler heads used on British rolling stock. I wonder if they thought the overheight Bachman "NEM" boxes were some kind of 00 standard.   

Edited June 15, 2013 by Pacific231G

[Dunsignalling]

I wonder if they thought the overheight Bachman "NEM" boxes were some kind of 00 standard.   

I hope not, but you may well be right! The variable height of pockets on UK-outline models has confused matters no end. 

 

Unfortunately, it still seems to be a problem, though not so much as before. I recently fitted Kadees to a pair of Bachmann SR brake vans. On one I followed my usual practice of ditching the NEM mount and fitting #146 couplers on home-made spacers. I wanted to try out both vans on a friend's layout later that day so decided to just plug in a pair of NEM heads on the second one.

 

Having heard from others that this was no longer an issue I was rather surprised to find the knuckles gauged low and the end of the tail was under rail-top height - a sure recipe for dramatic derailments! Wanting a quick fix, I decided to try a ruse I have noticed on some diesel shunters. I removed the pocket and glued a #20 directly into to the fixed part of the mount. Result: perfect alignment. 

 

The van appears to behave normally but, as suggested by someone in an earlier post, how these couplers will interact with others that have been rigidly mounted is uncertain. A bit of Initial fiddling about suggests they will be OK so long as both vehicles are in line over the magnet, i.e. neither is partially on a curve. 

 

John

[Dunsignalling]

You'd get a better idea of use on UK layouts by discretely surveying exhibition layouts at shows, asking Kadee how many they sell will include figures for US layouts where they are considered to be the standard.

As well as On30 and O-16.5 Narrow Gauge users, of whom a majority appear to use HO Kadees if exhibition layouts are anything to go by. Much of the initial advice I obtained about using Kadees came from such a modeller.

 

John

[47137]

My preferred method (#146) is to glue the box to the wagon then use the nylon screw to secure the lid after tapping a hole in the chassis.

 

This requires the wagon to be dismantled unless you are willing to drill and tap the hole through the steel weight. I replace the steel weight with lead flashing achieve my target weight anyway so it's all become part of a standard routine.

If you dismantle the wagon you can trim the steel weight at each end, I think this is easier than drilling it. I have just done a couple of wagons like the one below ... these are #146 couplers, assembled the night before (and left to dry out), fixed up with an M2 bolt and nut, adjusted and tried out, and finally cemented to stop the boxes turning. I have discovered if I cut the right amount off the moulded-on mounts for the original NEM pockets, the standard #242 box fits without having to trim it down. I did try putting washers below the M2 nuts but there wasn't quite enough room to have the bolt long enough to fill the nut and get the body moulding back on.

 

 

[Dunsignalling]

If you dismantle the wagon you can trim the steel weight at each end, I think this is easier than drilling it. I have just done a couple of wagons like the one below ... these are #146 couplers, assembled the night before (and left to dry out), fixed up with an M2 bolt and nut, adjusted and tried out, and finally cemented to stop the boxes turning. I have discovered if I cut the right amount off the moulded-on mounts for the original NEM pockets, the standard #242 box fits without having to trim it down. I did try putting washers below the M2 nuts but there wasn't quite enough room to have the bolt long enough to fill the nut and get the body moulding back on.

 

DSCF9871.jpg

 

DSCF9870.jpg

Another option, which also avoids the need to cut the weight, is to put a countersunk screw through a tapped hole from above and secured with a spot of superglue to stop it turning. Then just add a washer and nut (ideally the thin sort sometimes called a half-nut) to the bottom and trim the bolt to length.

 

This upside-down method leaves the maximum amount of room inside the chassis moulding for weight which I find helpful for opens or Conflats that will sometimes run empty (I use removable loads). Under these circumstances, I reduce my target weight for the wagon to 35g so that it won't become unduly heavy when loaded but still has enough inertia to minimise non-coupling when empty.

 

John

Edited June 15, 2013 by Dunsignalling

[Pacific231G]

I hope not, but you may well be right! The variable height of pockets on UK-outline models has confused matters no end. 

 

Unfortunately, it still seems to be a problem, though not so much as before.

 

The van appears to behave normally but, as suggested by someone in an earlier post, how these couplers will interact with others that have been rigidly mounted is uncertain. A bit of Initial fiddling about suggests they will be OK so long as both vehicles are in line over the magnet, i.e. neither is partially on a curve. 

 

John

Not just UK outline models either. I model European H0 and in theory should just be able to take Kadees out of the packet, plug them into the NEM boxes and start shunting, in my dreams!!

It's irritating because, when I was modelling US HO way back in the late 70s and early 80s, fitting Kadees into the standard draft boxes of all sorts of stock was very rarely a problem. I didn't even own a pair of Kadee pin pliars. The RP25 wheelsets also gave far more accurate horizontal alignment. I think this all reflects the greater influence of the NMRA. If you're a manufacturer selling into the US market and don't follow their standards you probably won't be in business for long.

Edited June 15, 2013 by Pacific231G