Close Coupling Coaches Project

Walkingthedog has got it right.
" If the coupling on coaches aren’t on the bogie they won’t go round all model railway curves "
Gormo

 

Well it`s horses for courses Sol.......
The American stock has no buffers to contend with which makes life a bit easier.
I have found with my tinkering, that it just depends on how far back from the end of the wagon / coach that the bogie is mounted. The further it is towards the center of the stock, the more swing you get at the end of the stock going through a curve.
When Frank Hornby and his mates designed the train set, the radii in the points and on the set track curves was so tight compared to real life, that they had no choice with bogie stock, but to mount the couplings on the bogies because of excessive swing in the bodies.
The later larger radius tracks were a step forward, however they could not leave their old customers behind with the new technology, so they stayed with stock configured to go through the tightest radius they were making for the basic train set.
This is still a commercial decision, based on the fact that they need their stock to run through 18" radius curves that come with train sets ( set track ) and also small points.
We now have the luxury of being able to build layouts with large radius curves and large radius points if we are blessed with the room to do it.
Of course with this facility, you could then easily add couplings to the buffer beams on your British stock because of the reduced body swing.
Model railways are a compromise, and regardless of what type of layout or stock you run, there will always be a compromise in some way attached to it.
I am glad you are able to run your coaches through larger radius track formations. It must be a pleasure to watch them run.
Gormo

 

Well I`m still tinkering and fiddling and adjusting folks.....not to mention re-designing and pinching ideas.
So this is where we are at the moment.
I have borrowed an idea here that I have seen on a video somewhere in the recent past, and that video was showcasing an O Gauge coupling system which worked by having a magnet at the end of a pivoting arm.
The magnets need to be polarity matched in that....North connects to South etc...but it works really well.
Uncoupling with a shunters pole may be difficult though...???




The magnet is a 3mm x 1mm neodymium and is glued to the end of a cut down track pin. The track pin has a nice flat head which is ideal.
The track pin is soldered to a copper T. I have used 0.80 mm thick copper wire which is reasonably rigid, yet soft enough to allow shaping.





These are prototypes ( rough ) models.
You will notice the screw protruding through the plastic ( not yet trimmed ). The securing screw location ( normally for T locks ) needed to be moved back away from the magnetic field because the magnet was attracted to the original location.





Here we are connected.
When the bogies approach each other, and the magnetic fields attract each other, the magnets automatically raise the coupling arms and the magnets clamp together.





As usual.....I`m still tinkering and adapting, so this stage now is all part of the refinement process and could change.
I tested the pulling power of this type of arrangement last night and found that it could pull 10 coaches plus 18 wagons up a gradient of 1 in 70 with no sign of letting go.
I will certainly test it to see what it takes to break it......but I think the locos will give up before the coupling lets go.....we`ll see...
This arrangement is also traveling well through S formations and cross overs etc.
As a matter of fact the bogies alone, connected as above, will easily pass through my dreaded S formation.
So excuse the pun, but we`re on the right track.
More as it happens
Gormo

 

OK here we go again folks.
Over the last few days I have been working through this coupling process, coming up with all sorts of arrangements until I arrived at a simple solution.
Still not happy with the simple solution as it had some set up issues, I have pressed on even further, reducing the build process, simplifying the components and using what is available.
I`ve had to go back to basics as far as my railway is concerned. The main focus is that, whatever coupling system is used, it must work with my track set up and look as good as possible. The rolling stock must be able to uncouple and couple in a partially obscured sliding fiddle yard.
So instead of creating a coupling for the the great and the good in model railways, I`m making a system that works for me. If it works for other people too, well that`s a bonus.
With all that in mind, I`ve come up with this simplified system. It is similar to the Hunt couplings, however it has a smaller profile and is adjustable.
These two coaches are on a generous curve at GCJ, however they will travel through an 18 " radius curve at the entrance to my sliding yard.
I feel they ( Hornby ) look a lot better minus their rather large tension locks and the closer coupling looks good as a train is traveling through the layout.





On the straight the buffers are spaced at about 4mm between buffers and that seems to be the closest they can go on my railway.





An overhead shot of a Lima ( left ) connected to a Hornby ( right ). Buffer spacing is 4mm as mentioned before.





For my railway, I will have the brake coaches, and also the first coach at the front of the rakes, fitted with one tension lock each at one end, to enable coupling to locomotives. The other ends of those coaches will be magnetic couplings.
This is my first brake coach set up in this way......tension lock at the rear and a magnetic coupling at the other end.





There is enough flexibility in the system to deal with slight variations in bogie height. The Lima on the left is slightly lower than the Hornby on the right and the coupling mount location is different as well, however the connection is secure.





In most cases the coupling can be fitted through the end of the bogie frame.




The coupling is mounted in such a way that it has some free movement in the horizontal and vertical planes. This deals with variations in height between bogies and also ensures that the bogies don`t derail on a tight radius curve.
I`ve got a couple more coaches to fit and then I`ll go through the process of making and fitting this system.
Gormo

 

G`day Pete,
Yes the Keen system is very good indeed......a bit more complicated than what I`m doing.?
http://keen-systems.com/Couplings.html
And the other player in the coupling game is Hunt from West Hill Wagon Works
https://www.westhillwagonworks.co.uk/hunt-couplings-new-c-2/
For those of you who want a good system without the fuss of building it yourself, these two systems offer really good solutions.
Gormo

 

Science indeed Chris !!!!!,
And magic and trickery and a bit of skulduggery to boot......not to mention the smoke and mirrors.......
Chris has nailed the solution " A minor amount of side play in the mount will prevent this and result in much better tracking of the bogies "

The answer is as below........a very simple.....very cheap arrangement that gives a buffer spacing which is much closer than tension locks and indeed can be tailored to suit your track arrangement.
I have two parts on my layout that have tight radius curves. They were not a problem until I started working on close coupling, however they are hidden tracks and do not count visually.
They do count operation wise and this is the thing with any coupling device. Any coupling system you use, has to be able to deal with the tightest radius that you use on your layout.
I have found through testing, that a 4mm spacing between buffers on 60 foot coaches will negotiate an 18" radius curve without buffer lock.....pushing or pulling......provided that the coupling has enough side play to prevent the bogies locking up.
So that measurement of 4mm is my limit on my railway. If we enlarge the radius we can bring the buffers closer together, so this system can adapt to your particular situation.
How you say.???..... well it`s adjustable.
First you have to determine what spacing you can allow....and this will require some testing.....but once your minimum clearance is determined you will be able to set your coaches all exactly the same regardless of coach manufacturer.
Here are two old Hornby coaches fitted with the magnetic system. The spacing between the buffers is 4mm.





Close up of above........the magnets are 1.5mm thick.





A very simple attachment to the bogies. The wire pin passing through bogie frame is a smaller diameter than the hole, which allows a good range of movement sideways.





Of course the major limitation of this system is that the coaches must be connected North /South because of the magnets polarity.
For me, this not really a problem as the coaches usually stay connected in rakes......but it may be an issue for some people.?????





A close up of above





In order to set these couplings at the correct spacing each time, I have made a simple jig.
The logic behind the jig is, that if we take the distance between the buffers as the critical measurement to get right, it does not really matter what brand of coach you are connecting to it`s neighbour, because if the couplings are all spaced accurately in relation to their buffers,.... it will work......simple as that.
If, on the other hand, we use a non adjustable coupling, you will get varying results mounting onto varying brands of coaches......because some manufactures buffers are longer than others, some manufacturers bogies are slightly different measurements to their competitors....you also have to factor in old stock connected to new stock etc....it goes on and on. A non adjustable coupling will not be as accurate on mixed stock and potentially will cause problems.

The jig has a right angled metal bracket fixed to one end and is secured by a screw underneath. The two pink pieces of timber are clamped by a piece of Aluminium angle secured to the base with a bolt and a wing nut.
The pink pieces are in effect a buffer stop and the magnet on the coupling will be drawn to the right angled bracket in the middle.









On this particular jig, the distance from the left hand back side of the jig to the front face of the right angled bracket is 42mm.
The distance from the left hand back side of the jig to the front face of the pink buffers is 44mm.
Those settings mean that the magnet / coupling face is 2mm forward of the buffers on the coach and therefore, if we connect another coach with the same settings to this coach, we will have a 4mm gap between the buffers.
The pink buffers are adjustable, so on layouts with larger radius curves, the distance between the buffers can be reduced.





This is what it takes to make a coupling.
Sewing pins with a plastic ball head......two of these disks from a 2 dollar shop would be about 2 dollars.
The pin is put in the vice and the head is filed flat to a slightly larger diameter than the magnet.
The resulting flat head is an ideal surface area to Super glue the magnet to.
We also have some wire insulation which slips nicely over the pin. The insulation is used to set the spacing on the coupling when using the jig.





This I think, is critical to the build.
5 second fix.........a liquid welding compound that sets using UV light
I use a small drop of this to secure the ends of the insulation on the pin shaft, once the correct distance has been determined using the jig.




I will do a video to show the process, but essentially, you remove any old coupling mounts from the bogie.
Remove the wheel set nearest the frame where you will be drilling a hole.
You drill a hole in the center and through the end of the bogie frame. The hole should be large enough to allow the pin to move from side to side freely, but small enough so that the insulation will not pass through it.
File flat the ball head on the pin to a diameter slightly larger than the magnet.
Super glue the magnet to the pin.
Polarity is important here, so you need to be careful which face of the magnet is glued to the pin.
Cut 10mm of insulation and slide it onto the pin about 5 mm from the point.
Put the jig on some straight track and attach the pin / magnet to the metal angle bracket.
The pin will now be held above the track and parallel to it.
Put the coach on the same track with the drilled bogie end facing the pin. Insert the pin into the hole in the bogie and whilst holding the jig square to the track, move the coach towards the jig until it`s buffers touch the pink buffer stops.
Withdraw the coach and you will see that the insulation has been pushed into the correct position on the pin.
Use the 5 second fix to secure the insulation to the pin between the end of the insulation and the pin head.
Now you can slide the pin into the bogie until it stops at the fixed insulation. Cut another small amount of insulation (5mm ) and slide over the pin on the inside of the bogie. Push it up against the back of the bogie frame and secure the insulation again with 5 second fix.
Trim off excess pin with snips
Re-fit the wheel set.....and you`re done.

Video to follow in a few days or so.
Gormo

 

Geez Gary !!!!,
How did you work that out......you must be a mind reader..????
Gormo