Kadee Couplers

[Butler Henderson]

The length of the shank is not always simply due to track radius, there a number of models where Kadees look neater with the draft box set behind, or well behind, the bufferbeam and this necessitates the use of a longer shank.

[47137]

One further question if I may regarding the fixing of couplings. I've previously indicated that I hope to use adhesive (solvent) to secure the draft boxes. How does one assess the amount of packing required, if any, prior to gluing the draft boxes to the chassis?

A while ago, I bought a packet of spare draft gear boxes and I use these if things go wrong.

 

What I do, is assemble the coupler into the box, tack the box onto the underframe with a drop of solvent, and put the model on a length of track. If the coupler is the right height, I flood the joint onto the underframe with solvent, and also put some droplets onto the box lid, so it doesn't fall off. If the coupler height is very wrong, think about an over- or under-set coupler. Otherwise, pull off the box and add a shim. But to be honest, after you have done a few wagons, you start to know which ones will be right first time.

 

Sometimes I wonder if the box lids should be left free to fall off. If a trip pin is too low and it hits a rail on a turnout, the wagon can take a nose dive to the floor.

 

- Richard.

[Suzie]

I always use the Kadee screws in to tapped holes. Then when I use the height gauge if packing is required I can just unscrew and pop in a shim or two.

[BR60103]

Tip 1: run a length of thread through the Kadee knuckle spring before you try to install it on the coupler.

 

Tip 2: one of the Platelayers made a device to measure the distance from the railhead to the underside of the vehicle where the coupler will be mounted. A piece of track on a board with a hole near one end (hole throgh board and sleepers) and a bit of metal over part of the hole. He used a lump and a c-clamp; I soldered a sheet of brass on. Use the stem of vernier calipers the measure from the metal strip to the wagon bottom. Kadee have a page with all the dimensions for all their couplers.

I think I posted a picture of my tool some time ago.

[Dunsignalling]

A while ago, I bought a packet of spare draft gear boxes and I use these if things go wrong.

 

What I do, is assemble the coupler into the box, tack the box onto the underframe with a drop of solvent, and put the model on a length of track. If the coupler is the right height, I flood the joint onto the underframe with solvent, and also put some droplets onto the box lid, so it doesn't fall off. If the coupler height is very wrong, think about an over- or under-set coupler. Otherwise, pull off the box and add a shim. But to be honest, after you have done a few wagons, you start to know which ones will be right first time.

 

Sometimes I wonder if the box lids should be left free to fall off. If a trip pin is too low and it hits a rail on a turnout, the wagon can take a nose dive to the floor.

 

- Richard.

Long term, the best plan is to glue the box on and secure the lid using one of Kadee's #256 screws.

 

Not fixing the lid causes the coupler ride a good millimetre lower than it does with it screwed in place, thereby increasing the risk.

 

I also set the trip pins rather higher than Kadee recommend, (1mm rather than the 1/64 in. specified) to avoid unwanted interaction with pway; they still uncouple when I want.

 

John

[Ray H]

Many thanks for the on-going comments, guidance and advice.

 

I also set the trip pins rather higher than Kadee recommend, (1mm rather than the 1/64 in. specified) to avoid unwanted interaction with pway; they still uncouple when I want.

 

John

Presumably you do this by bending the trip pin using the Kadee pliers or do you push the trip pin upwards through the coupling? I've noted that the top (outer) end of some of the pins - the end in contact with the coupling - catches on the underside of the (dummy 3-link) hook which compromises the coupling's movement ability. I've taken a file to the underside of the hook where this occurs to resolve the problem.

[Dunsignalling]

Many thanks for the on-going comments, guidance and advice.

 

 

Presumably you do this by bending the trip pin using the Kadee pliers or do you push the trip pin upwards through the coupling? I've noted that the top (outer) end of some of the pins - the end in contact with the coupling - catches on the underside of the (dummy 3-link) hook which compromises the coupling's movement ability. I've taken a file to the underside of the hook where this occurs to resolve the problem.

Yes, I use the Kadee pliers. I also round off the bottom corner at the end of the trip pin as a further precaution. However, when bending the pin to raise the clearance, the end sometimes curves upwards slightly making filing unnecessary.

 

The coupling hook clearance can be especially irritating on Bachmann wagons where the hook is a bit on the hefty side anyway. I generally snip them off and add MJT whitemetal hooks from Dart Castings which are much smaller. 

 

 

Regards,

 

John

Edited January 22, 2016 by Dunsignalling

[BR60103]

Bending the trip pin: there is another bending pliers that have a 2 part jaw on one side and one part on the other; the one part goes between the two. Kadee's have a round jaw and a half round that it fits into.

Before they made those, we used long-nosed pliers -- one end one the trip pin at the top of the knuckle and the other at the business end, the pliers being held out at right sngles to the car end. This required a very gentle squeeze as a fraction too much would bend the pin into a U shape.

Using the pliers across the pin let you lengthen it.

[Dungrange]

With all this talk of problems using permanent magnets for uncoupling, I'm surprised nobody has used electromagnets. Kadee does one which is big and unsightly; there must be a way of making something a lot smaller that would work.

 

I would have thought that electromagnets would have been the cure to most problems with permanent magnets and that was my assumed approach if I eventually decide to adopt Kadee couplings.  Why you think the Kadee electromagnet (#309) is big and unsightly?  My understanding is that this is mounted under the sleepers and apart from the three screws that seem to attach it to the underside of the track, I don't see anything unsightly with this.  Does anyone have experience of using these?

[Butler Henderson]

_{An alternative to the electro magnet is to hinge an undertrack magnet driven up and down by a servo. The problem I usually have with the magnets is not wheels being attracted to them as I use the plastic centre axle metal wheels that Bachmann originally used on UK stock but rather a judder in the motion of the train causing it to split into two.}

[Dunsignalling]

I would have thought that electromagnets would have been the cure to most problems with permanent magnets and that was my assumed approach if I eventually decide to adopt Kadee couplings.  Why you think the Kadee electromagnet (#309) is big and unsightly?  My understanding is that this is mounted under the sleepers and apart from the three screws that seem to attach it to the underside of the track, I don't see anything unsightly with this.  Does anyone have experience of using these?

Absolutely correct. The #309 uncoupler itself should disappear completely once it has been fixed in place and the track has been ballasted.

 

How noticeable the fixing to the track base will be is dependent on how it is done. There are four screws, two hold the mounting bar to the uncoupler and the other two fix the mounting bar to the sleepers [EDIT: the photo shows three here] . Only the latter two will be visible and, so long as they are countersunk a tad deep, they should be easy to hide with a spot of filler and paint. 

 

The old #307 uncoupler actually came up between the rails and my modification mentioned in an earlier post dispensed with the mounting bar (which sat on top of the sleepers on that unit), leaving only the ends of the pole-pieces visible; the space between them being infilled with short lengths of sleeper and ballasted. 

 

The uncoupler was, therefore, not attached to the track as intended, and had to be secured tightly within its aperture in the baseboard instead.

 

I was heartily sick of the job by the time I had done 20-odd and would have been delighted had the #309 been available then.

 

EDIT: If you go on to www.Kadee.com - products - uncouplers - click on 309 and you will get a diagram showing how it all goes together and photos of a completed unit fixed to a piece of track. A further click on  #309 beneath the pictures will bring up the full instruction sheet.

 

John

Edited January 24, 2016 by Dunsignalling

[Norm81]

With all this talk of problems using permanent magnets for uncoupling, I'm surprised nobody has used electromagnets. Kadee does one which is big and unsightly; there must be a way of making something a lot smaller that would work.

Someone did but the website disappeared. They used two bolts, one under each rail with a separation along the rails of between 5-10mm. Then wound two coils on the bolts in such a way that they had opposing poles at the top ends. I was going to give it a try but as I say the website is now gone.

 

I think the 5-10mm is to match where the ends of the two coupled trip pins are, also I really don't think the poles have to be opposite, you just need a strong enough magnetic field - would have to verify this as I'm speculating.

[knitpick]

Norm81 - from my knowledge of Physics, if you have two magnetic poles of the same polarity, they repel and there is a dead space between them with no magnetic field at all, gradually increasing until you get to the pole itself; there will be no magnetic field to attract the trip pin.  With opposite poles, there is a very strong field between them and each trip pin will be strongly attracted to the nearer pole.  

 

As you say, you need a strong field and this is best achieved using opposite poles.  If you check the Kaydee magnets that lie between the tracks you will find the North Pole is one long edge and the South Pole is the other long edge and the field goes across the track. 

[ejstubbs]

Fundamentally, the trip pins need to move sideways, which means that the magnetic field needs to be at right angles to the direction of the track.  If the uncoupling magnet had a north pole at one and a south pole at the other then the magnetic field would run parallel to the track and the trip pin would not move.  This can easily be demonstrated by taking a single Kadee coupler and lowering it by hand towards an uncoupling magnet at right angles to the normal direction: the trip pin will not move, even when it is in contact with the surface of the magnet.

 

Since this can be demonstrated using a single coupler, it disproves the theory that some people put forward about induced magnetism in the trip pins causing them to repel.

 

It is worth keeping in mind how the stock uncoupling magnets work when experimenting with using small, discrete neodymium magnets in place of the ferric slabs that Kadee sell.

[47137]

Norm81 - from my knowledge of Physics, if you have two magnetic poles of the same polarity, they repel and there is a dead space between them with no magnetic field at all, gradually increasing until you get to the pole itself; there will be no magnetic field to attract the trip pin.  With opposite poles, there is a very strong field between them and each trip pin will be strongly attracted to the nearer pole.  

 

As you say, you need a strong field and this is best achieved using opposite poles.  If you check the Kaydee magnets that lie between the tracks you will find the North Pole is one long edge and the South Pole is the other long edge and the field goes across the track. 

 

 

Fundamentally, the trip pins need to move sideways, which means that the magnetic field needs to be at right angles to the direction of the track.  If the uncoupling magnet had a north pole at one and a south pole at the other then the magnetic field would run parallel to the track and the trip pin would not move.  This can easily be demonstrated by taking a single Kadee coupler and lowering it by hand towards an uncoupling magnet at right angles to the normal direction: the trip pin will not move, even when it is in contact with the surface of the magnet.

 

Since this can be demonstrated using a single coupler, it disproves the theory that some people put forward about induced magnetism in the trip pins causing them to repel.

 

It is worth keeping in mind how the stock uncoupling magnets work when experimenting with using small, discrete neodymium magnets in place of the ferric slabs that Kadee sell.

I wrote up an account of Kadee magnets on my blog last November - which seems to be at odds with this.

 

The characteristics I see are that the original Kadee magnets both repel from the centre and attract at the edges. This implies the trip pins are lightly magnetised, and this would tally with what I saw when I was setting up my Neodymium blocks, where I had to be careful to get the magnets the right way round to swing the trip pins in the correct direction.

 

I'm happy to change the blog if someone shows this is wrong.

 

Edit: see good explanation in post by ejstubbs.

 

- Richard.

Edited January 25, 2016 by 47137

[ejstubbs]

The characteristics I see are that the original Kadee magnets both repel from the centre and attract at the edges.

 

The uncoupler magnets definitely have opposite poles at the two long edges.  That's easy to see by laying two of them side by side: one way round they will repel each other, the other way round they attract.  If you have a magnetic compass you can easily find out which is the north pole of the uncoupling magnet, and which is the south, according to which end of the compass needle each side attracts.

 

It's simply not possible to make a permanent magnet with one pole in the middle and the opposite pole at each end, which is what you seem to be suggesting, and what the diagram on your blog suggests.  If you could take one of the uncoupling magnets and magically split it lengthways, the newly-exposed faces of the resulting thin magnets will be opposite poles to the corresponding outer edges ie you'd end up with two thin magnets each with one north pole and one south.  That's how magnets work.  (What you suggest would actually be a physical marvel: effectively a magnetic monopole, which has never been observed experimentally).

 

This implies the trip pins are lightly magnetised

 

I've done some experiments with a tiny sliver of staple wire about 1mm long.  Some couplers' trip pins will just about pick it up.  Others leave it totally unaffected.  I reckon some of the pins may pick up a very small amount of residual magnetism from the uncoupling magnets, but it's not anything like enough to make the pin be attracted to one pole and repelled from the other.  If it were then the Kadee system would be basically useless: since the pins on all couplers would have to have the same magnetic polarity at their tips, the pins on two couplers would repel each other and stock would never couple!

 

Since it can easily be proven that the uncoupling magnet has opposite poles on each side, and the trip pin will deflect to the right, viewed in the direction of travel, regardless of the direction from which the vehicle approaches the uncoupling magnet, such residual magnetism as may exist in the trip pin is demonstrably of no consequence compared to the strength of the field within 0.8mm of the surface of the uncoupling magnet.

 

this would tally with what I saw when I was setting up my Neodymium blocks, where I had to be careful to get the magnets the right way round to swing the trip pins in the correct direction.

 

What you need to do with the neodymium magnets is to create a magnetic field perpendicular to the direction of the track.  That means having opposite poles directly opposite each other.  My neo bar magnets have the N and S poles on the flat faces of the bars.  If you put them with the N poles both uppermost then they will largely cancel each other out in the space between them ie where the trip pins are.  If you put them opposite ways round then they work together to create a strong perpendicular magnetic field between the rails.

 

My freehand drawing skills are far from good, and my handwriting is appalling, but hopefully these scribbles will be adequate to illustrate what I mean:

 

 

Edited January 25, 2016 by ejstubbs

[Ray H]

The smaller magnets arrived in the post today and I've been experimenting further.

 

 

I'm again using the spread out sleepering of one of the points within the fiddle yard at the test ground. Staggering the magnets slightly appears to help. The initial trial was a little further along the siding at the end of a return curve and the results weren't brilliant. However I'm still using NEM couplings pending the arrival of the 14x series (and others later) in the week. I'll then attempt to glue the test magnets in place and see what happens then.

 

The one thing that I have noticed is that neither the trip pins nor the wheels/axles seem as attracted to these magnets as they did to the larger ones - that's attracted as in attempting to make physical contact.

Edited January 25, 2016 by Ray H

[47137]

 

The uncoupler magnets definitely have opposite poles at the two long edges ...

Thanks for the whole of your explanation. I've taken the magnetic monopole out of my blog entry. I really wish I had a packet of iron filings to play with before I write anything else on magnets. Nevertheless, what I made (as per the blog entry) does work.

 

- Richard.

[Ray H]

The Kadee test pack and a pack each of 141 & 146 were collected from the model shop this morning enabling me to spend some time with further experiments.

 

The first comment concerns the Code 83 magnet that comes in the test kit. I used a couple of wagons that I've fitted with 141/146 couplings and had glued the magnet to the track towards the end of a fairly long straight section. The uncoupling success rate was not great no matter which way I pushed the wagons. I'd estimate probably no more than 60%. I believe I need to improve this performance with a supplied magnet before I carry on trying various other types of magnet.

 

The uncoupling tool is also included in the test pack. Like the toothpick that I tried before, I have had little success with it. Is there a knack to using it? I can hardly get it between the two knuckles and the tool then seems to stop the couplings parting.

 

I've used a couple of Bachmann coke wagons for the latest testing. I've removed the NEM pocket and the socket mount screwed to the underside of the chassis/body. That mount sits in a slight recess with a short narrow straight raised section parallel to the axles towards the back of the recess. I tried several different couplers but only the draft box that comes with the !41/146 couplers sold as pairs. I initially thought that I'd need to remove the raised sections of the recess and did this on one end of one wagon. I also removed the upper lip on the front end of the draft box to give a greater gluing surface. I only removed the upper lip on the draft box on the second wagon and made no changes to the wagon (apart from securing the draft box to its underside).

 

Earlier tests with the NEM coupling range 17 through to 20 were adjudged to have failed because of the excess of vertical movement in the coupling in the NEM socket. Today's experiments suggest that the vertical movement at the knuckle end of the coupling is around 3mm - 1.5mm either side of the vertical centre line which seems excessive.

 

I'm convinced that the Kadees must work otherwise so many people wouldn't be using them in the UK so I must be doing something wrong (or perhaps several). Can anyone see where I need to change what I'm doing based on the tales above?

 

Thanks

[Dunsignalling]

The Kadee test pack and a pack each of 141 & 146 were collected from the model shop this morning enabling me to spend some time with further experiments.

 

The first comment concerns the Code 83 magnet that comes in the test kit. I used a couple of wagons that I've fitted with 141/146 couplings and had glued the magnet to the track towards the end of a fairly long straight section. The uncoupling success rate was not great no matter which way I pushed the wagons. I'd estimate probably no more than 60%. I believe I need to improve this performance with a supplied magnet before I carry on trying various other types of magnet.

 

The uncoupling tool is also included in the test pack. Like the toothpick that I tried before, I have had little success with it. Is there a knack to using it? I can hardly get it between the two knuckles and the tool then seems to stop the couplings parting.

 

I've used a couple of Bachmann coke wagons for the latest testing. I've removed the NEM pocket and the socket mount screwed to the underside of the chassis/body. That mount sits in a slight recess with a short narrow straight raised section parallel to the axles towards the back of the recess. I tried several different couplers but only the draft box that comes with the !41/146 couplers sold as pairs. I initially thought that I'd need to remove the raised sections of the recess and did this on one end of one wagon. I also removed the upper lip on the front end of the draft box to give a greater gluing surface. I only removed the upper lip on the draft box on the second wagon and made no changes to the wagon (apart from securing the draft box to its underside).

 

Earlier tests with the NEM coupling range 17 through to 20 were adjudged to have failed because of the excess of vertical movement in the coupling in the NEM socket. Today's experiments suggest that the vertical movement at the knuckle end of the coupling is around 3mm - 1.5mm either side of the vertical centre line which seems excessive.

 

I'm convinced that the Kadees must work otherwise so many people wouldn't be using them in the UK so I must be doing something wrong (or perhaps several). Can anyone see where I need to change what I'm doing based on the tales above?

 

Thanks

First thing that springs to mind is that you might have trapped one of the whiskers when you fitted the lid to the draft box; I've had it happen a few times and the result is very odd.

 

There is a fair bit of vertical slop in 146/141 couplers if the lid is only clipped on - much of it disappears if you fix the lid by screw (best) or glue.

 

You can get rid of the vertical slop in Bachmann NEM pockets by adding a strip of thin card below the Kadee 17etc.

 

However, a lot of Bachmann pockets are too high and the tail of the coupler may be too far away from the magnet - have you got a height gauge in the kit?

 

In-track magnets - Code 83 ones are the right thickness for that height of track - if you are using Code 100 you will need a bit of thin card under it to bring it up to working height. It is also quite important to ensure [a] that the magnet is central and parallel between the rails and both wagons are fully on straight track when attempting to uncouple (i.e. the magnet is far enough from the end of the curve). There is a gluing jig available to ensure [a] but it's not difficult to do it by eye.

 

If you check everything over as above, everything should work as intended. Overall, it sounds like you are suffering from several things being a bit out rather than one thing being drastically wrong.

 

Best wishes

 

John

 

PS I've never had much success with the manual uncoupling tool, either. I currently use a wooden Kebab skewer which is much thicker and works better for me. 

Edited January 30, 2016 by Dunsignalling

[Removed a/c]

with regards to the uncoupling tool, are you using the right end, more like spade that just the point. should be insert and twist I believe? When you say the 17-20s failed what do you mean? Failed at what? Can I ask why you are removing then NEM pockets, are the at the incorrect height?

Edited January 30, 2016 by thebritfarmer

[BR60103]

Some of the crew at Lostock Junction manage to diddle the couplings open with a pointed stick (sharpened bamboo food skewer) but I never can.

While you're experimenting, try not to use a permanent glue on the magnets. I used the head of a nail or spike for years.

 

Just had a thought: I bet the magnets play the dickens with copperclad tracks.

[Ray H]

Thanks for the responses so far.

 

First thing that springs to mind is that you might have trapped one of the whiskers when you fitted the lid to the draft box; I've had it happen a few times and the result is very odd.

I don't believe so as the couplings seem to move from side to side and return to centre quite freely but I will check.

 

There is a fair bit of vertical slop in 146/141 couplers if the lid is only clipped on - much of it disappears if you fix the lid by screw (best) or glue.

I was hoping not to have to use screws to avoid puncturing the top side of the wagon floor from below. There were some screws in the pack but they looked more like machine screws i.e. not suitable for screwing into untapped holes. Can you suggest a suitable diameter/length screw?

 

You can get rid of the vertical slop in Bachmann NEM pockets by adding a strip of thin card below the Kadee 17etc.

I tried that with the NEM couplings but the mount also allowed vertical movement which I overcame on one wagon by gluing the mount to the underside of the wagon floor. The downside to this is that the sideways movement of the coupling is then compromised. I did try to add the thin round washer that came in the kit inside the draft box of the 141/146 coupling but I couldn't get the lid to clip on afterwards.

 

However, a lot of Bachmann pockets are too high and the tail of the coupler may be too far away from the magnet - have you got a height gauge in the kit?

I bought a height gauge with the initial batch of NEM couplings and there is a height gauge in the kit so I have a spare!

 

In-track magnets - Code 83 ones are the right thickness for that height of track - if you are using Code 100 you will need a bit of thin card under it to bring it up to working height. It is also quite important to ensure [a] that the magnet is central and parallel between the rails and both wagons are fully on straight track when attempting to uncouple (i.e. the magnet is far enough from the end of the curve). There is a gluing jig available to ensure [a] but it's not difficult to do it by eye.

I'm using code 75 rail and the plain track is SMP. The magnet is more than 2ft from one end of a yard of straight track (and 1ft from the other!). Central alignment seems quite easy. I've temporarily fixed it down with a couple of spots of superglue. Even with the wagons uncoupled the magnet doesn't appear to be as strong as its rare earth cousins which it probably doesn't need to be. However, I think I can see why it may need to be as long as it is because I would have expected the wagons to uncouple once both were over the end of the magnet rather than a good way along. I also found that the more abrupt stopping which is more of a feature with DC rather than DCC brought better results.

 

If you check everything over as above, everything should work as intended. Overall, it sounds like you are suffering from several things being a bit out rather than one thing being drastically wrong.

 

Best wishes

 

John

 

PS I've never had much success with the manual uncoupling tool, either. I currently use a wooden Kebab skewer which is much thicker and works better for me.

A colleague uses Kadees on his layout and the tool worked fine on them (which is why I was glad there was one in the pack). However, his layout is SM32, not OO!

 

Some of the crew at Lostock Junction manage to diddle the couplings open with a pointed stick (sharpened bamboo food skewer) but I never can.

While you're experimenting, try not to use a permanent glue on the magnets. I used the head of a nail or spike for years.

 

Just had a thought: I bet the magnets play the dickens with copper-clad tracks.

I thought you were joking at first until I realised that you meant they could provide an electrical bridge between the two insulated parts. Fortunately mine will all be on SMP track (if I use them). I'd be content with the non-delayed uncouplers (No. 312) at the ends of sidings but I can't tell whether the 312 magnet is for code 100 or code 83 rail. I note that the 312 magnet should be mounted with the top 1/64th inch above rail level. I haven't checked that on the magnet I've fitted but I suspect that may well be the case as code 75 rail isn't as high as code 83.

 

with regards to the uncoupling tool, are you using the right end, more like spade that just the point. should be insert and twist I believe? When you say the 17-20s failed what do you mean? Failed at what? Can I ask why you are removing then NEM pockets, are the at the incorrect height?

I have tried both ends of the tool. I wonder whether it doesn't need to be "inserted" between the knuckles as much as I have done i.e. I've tended to push it down as far as it will go.

 

The NEM couplings struggled to work using rare earth magnets of different sizes/strengths because the trip pin was able to drop far enough to make physical contact with the magnet. As indicated above I tried adding a thin spacer to the socket under the coupling but the give in the NEM socket mount - the fishtail - was enough to still allow contact between magnet and trip pin. The only way to stop that was to glue the NEM socket to the underside of the wagon floor an this limited the sideways movement of the coupling head.

[Smiffy2]

Kadee sell a drill and tap set that includes a through-hole drill and a drill for tapping (#246). The sizes are Imperial, 2-56, but suitable screws can be obtained (I just did a Google search). I got the type that uses an Allen key, much easier to handle.

 

http://www.ebay.co.uk/itm/361384057282?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Screws from

http://www.accu.co.uk/en/

[kevinlms]

 

I was hoping not to have to use screws to avoid puncturing the top side of the wagon floor from below. There were some screws in the pack but they looked more like machine screws i.e. not suitable for screwing into untapped holes. Can you suggest a suitable diameter/length screw?

 

 

Are these the nylon screws in the pack. What works is an 8BA tap if you already have one. It shouldn't work, but it does!

 

Edit to add.

Try it out on a thick piece of Plastikard.

Edited January 31, 2016 by kevinlms