Project # 2 - Body Mounting Kadee Couplers!

BODY MOUNTING KADEE COUPLERS TO IMPROVE SCALE APPEARANCE

 

Last reviewed and revised October 27, 2015 (When writing my articles, I have tried to be conscious of the time it takes to view them. Some modelers only have a dial-up connection to the Internet and sizeable image files embedded in the text can slow viewing down quite a bit. To counteract this, I originally kept my images hidden behind key words in the text so that you view them only when you click on those words, but somehow this feature has been disabled. If you want to see the original article, with images, please e-mail me at lawrence_d_cooper@yahoo.com.

 

INTRODUCTION and OVERVIEW

In my personal quest for more realism in my 1/29 models and more reliable operation of long trains, I have made the decision to body mount all my couplers. Since this is an area that only a few venture into, I thought you would all like to see a little more information on the subject.

The couplers that come on most Large Scale cars from the factory are grossly oversize and contribute to many derailments on longer trains because they are truck mounted. Replacing these with Kadee couplers and body mounting them can repair both of these problems.

First, let's talk about the physical stuff. If you are still using any really small radius curves (say less than 6 ft. diameter) or if your trackwork undulates up and down a lot you may not be a candidate for body mounted couplers. The factory couplers were designed with these limiting factors in mind and you should retain them. If you have already fixed these problems, then you could benefit from body mounted coouplers.

Success with body mounted couplers can best be obtained when strict track, wheel, and height standards are rigorously implemented on your layout.

Repeating, for emphasis, success with body mounted couplers has more to do with good, prototypical (long radius curves and switches) trackwork than any other factor. I model indoors on hand-laid track in order to be able to better control these elements of my hobby and, as a result, have had no problems at all with finer flanges, more tightly laid switches and crossovers or with body mounted couplers. However, outdoor railroaders can adhere to the same standards by using the new larger radius curves and paying some attention to seasonal maintenance.

If you are like me and want to see more realism in your Large Scale Railroading then this article may help.

 

Correct Height Cars?

Next let me say that I am writing this article, and illustrating it, from the perspective of mounting Kadee #820 couplers on to cars that are the "correct" height off of the rails. This implies that, if the original car stands too high off the rails, it must be lowered to the correct height first and then the techniques I describe will work without modification. (See my other article on LOWERING ARISTO BOX CARS TO IMPROVE THEIR SCALE APPEARANCE).

One of the things that affects this height is the diameter of the car's wheels. I am using MDC plastic wheels that are slightly smaller than the original Aristo Wheels. The MDC wheels measure 1.175 inches in major diameter at the tread while the Aristo wheels measure 1.195 inches. (See my other article on MODIFYING ARISTO FREIGHT CAR TRUCKS TO IMPROVE THEIR SCALE APPEARANCE). One thing you will certainly want to do is cut off the truck mounted coupler tongue that is built into the truck bolster. For both freight and passenger car trucks, it is a simple cut across the width and then a little dress up filing to produce a tongueless bolster.

I will attempt to describe any variations that I can think of for cars that haven't been lowered and will edit this article with additional suggestions as you all make me aware of them.

 

Order of Presentation

Now let's get started.

I will be describing how to body mount Kadee #820 couplers on several different cars, progressing from the simplest task to the most complex, as measured by the difficulty encountered in making the "coupler height adapters. Here is the order of the cars that I will present:

1. Aristo Flat Cars and Gondola Cars, which are at the right floor height out of the box.

2. LGB Box Cars, which are at the right floor height out of the box and require only a simple adapter.

3. Aristo Box Cars, which must be lowered and require a slightly more complex adapter.

4. USA Trains Cabeese, which are at the right floor height but require a complex adapter.

5. Aristo 2 Bay Covered Hoppers, which must be lowered and require an even more complex adapter.

6. Aristo Streamlined Passenger Cars, which must be lowered and require a pretty thick adapter. (Under Construction)

7. Aristo Heavyweight Passenger Cars, which are the right floor height but require a complex adapter. (Under Construction)

I have had great luck with body mounting my couplers. I hope that this article helps you to have the same experience.

 

ADDING BODY MOUNTED KADEES TO ARISTO FLATS AND GONS

Let's start with the easiest car there is for this kind of project - the Aristo Flat and Gondola cars.

The unique construction of these cars, with the underframe mounted up inside the car sides, causes these cars to ride at almost the correct height right out of the box. This means that no coupler height adapter is needed, unlike the cars that follow.

The first step in this conversion will be to invert the car and remove the trucks. You will need to cut the coupler mounting tongue off of the truck and put the large, unrealistic Aristo coupler in your scrap bin.

This leaves a bare end area that looks like this.

Now we need to drill some holes in the plastic with a #43 drill bit (.089).

Place the Kadee #820 draft gear on the end of the car with the flange up against the car end, resting on the bottom of both the end of the car and the "coupler extension support tab".

Now let's use this assembly as a jig to PARTIALLY DRILL two #43 holes through the side mount holes.

Make sure that you do not drill all the way through both layers of plastic. There is an underframe layer and then, next, the actual inside of the car floor. DO NOT DRILL THROUGH THE CAR FLOOR.

See the image and note that I am angling the drill bit tip back toward the center of the car just a bit to ensure a snug fit.

When these two holes are drilled, the car end should look like this.

Now we will mount the Kadee #820 draft gear with two 4-40 round headed machine screws that are 3/4 inch long. These should self tap through the two #43 holes you just drilled and will only be long enough to go through and engage the underframe layer of plastic. Snug these screws down.

To ensure that the draft gear is secure, we will drill one more #43 hole. Carefully drill a hole straight down into the "coupler extension support tab" through the rearmost hole in the Kadee draft gear, as shown in this image.

Insert a 4-40 round headed machine screw that is 1/2 inch long into the hole you just drilled and snug it down.

When finished, the car should look like this.

 

Testing for Correct Height

Re-attach the trucks, minus their coupler tongues, and place the car on the rails.

I use a Kadee #1 gauge coupler height gauge and I recommend that you do too.

In any case, make some kind of gauge that will allow you to apply the same standard measurement to all your cars without using another car to judge the correct height.

I think you will find that these cars, and their couplers, are now the correct height and that these are the simplest cars to perform this conversion on.

Now on to a car that is a bit more tricky.

 

ADDING BODY MOUNTED KADEES TO LGB BOX CARS

The process for LGB cars is quite simple since, like the flats and gons, the LGB Box Cars do not need to be lowered.

Start by removing the trucks and cut the coupler mounting tongue off of the truck and put the large, unrealistic LGB Horn/Hook coupler in your scrap bin.

Now drill two #43 holes in the car floor along the centerline spaced at .480 and 1.440 inches from the outside edge of the car end respectively.

When finished, the car end will look like this.

The positioning of these holes is very important because it determines the location of the Kadee draft gear and can affect the overhang and car spacing adversely if done incorrectly. This hole spacing has been arrived at by trial and error and produces a mounting that just sticks out over the edge of the car a spaces cars apart about 1 inch.

 

The LGB Box Car Coupler Height Adapter

This piece is as simple as it gets. Simply start with some 1/8" x 3/4" wide stock. Plastic will do but I found some galvanized steel at my local hardware store and used it. Cut the stock to just fit between the body bolster and the inside lip of the car end. Drill two oversize holes in this piece to provide wiggle room for the 4/40 screws (try a 1/4 drill bit). Now file all the burrs off and paint the piece flat black so that it looks like this.

Place the adapter on the car end like this.

Next mount the Kadee #820 draft gear using two 4/40 x 5/8ths inch round head machine screws by screwing them into the plastic and allowing them to self tap as on the Aristo car. Snug them down until the coupler shank starts to stick in it's swing and then back off 1/4 turn.

Replace the trucks and turn the car over and it should look like this.

 

Testing for Correct Height

As before, test with a coupler height gauge but I think you will find that it comes out just fine.

 

ADDING BODY MOUNTED KADEES TO ARISTO BOX CARS

While the title of this section states "Box Cars" it should be obvious that the same technique applies to Aristo Stock Cars and Aristo Reefers as well. Rememeber that these cars come from that factory standing 3/16th too tall off the rails and need to be lowered to achieve the realism we seek.

Start the coupler conversion process by inverting the car and removing the trucks.

You will need to cut the coupler mounting tongue off of the truck and put the large, unrealistic Aristo coupler in your scrap bin.

When finished, you will be presented with this view.

Now drill two holes in the floor with a #43 drill bit (.089 diameter) approximately .40 from the outside edge of the end of the car and .70 apart so that the midline of the distance between the holes is on the centerline of the car.

I use a jig that ensures that the holes are centered and in virtually the same place every time.

The positioning of these holes is very important because it determines the location of the Kadee draft gear and can affect the overhang and car spacing adversely if done incorrectly.

When you are finished, you will be presented with this view.

 

The ARISTO Box Car Coupler Height Adapter

Now make a Coupler Height Adapter like the one shown in this picture.

The Coupler Height Adapter is a simple piece of plastic (mine is a casting) that is no wider than the Kadee coupler body. Mine is 1/2 inch wide.

The adapter's length can either be short or long. The short version, as shown, is made to match the distance to the end of the car from the "coupler extension support tab" that is cast into the floor and measures approximately 1.1 inches long. The long version would be made to match the distance between the truck bolster and the end of the car in cases where you had removed the "coupler extension support tab".

The most important dimension for this adapter is it's thickness. For Aristo Box Cars that have been lowered by 3/16th of an inch, the thickness should be .155 inches. If you have not lowered your car then it should be .3425 inches (.155+.1875 inches).

I put a 1/4 inch diameter hole in my adapter to permit the head of the attachment screw on the end of the body to have some clearance. You might want to do the same.

I also made a small lip on the end of my adapter to allow it to space the Kadee coupler out from the end of the body by about .040 of an inch to create the car spacing I was looking for and to present a pleasing visual image. The height of the lip is about .040 inches as well. However, this lip is optional as long as the #43 holes are drilled correctly as noted above.

When you have made the adapter (by the way, I have these castings available and will gladly share them with anyone who wants to copy them) you should paint it flat black and place it on the car floor as shown.

Now assemble the Kadee #820 coupler components and note that they come with a mounting hole on the back end of the coupler. I trim this off to produce a flat-backed piece that then buts up against the "coupler extension support tab" that is cast into the floor. You would not need to do this if you have removed that tab.

I now place two round head 4-40 x 5/8ths machine screws in the two side holes on the Kadee coupler body and screw them into the plastic. The #43 holes that you drilled earlier are the correct diameter to permit these screws to self tap and you will find that they go in very snuggly and will hold forever without a nut on the inside of the car.

Tighten these screws until the coupler sits parallel to the car body and the coupler shank just swings freely. Take care to make sure that the adapter is centered on the Kadee draft gear. I snug them down until the coupler shank sticks a little and then back them off a quarter turn.

When finished, it should look like this.

 

Testing for Correct Height and Spacing

Re-attach the trucks, minus their coupler tongues, and place the car on the rails.

I use a Kadee #1 gauge coupler height gauge and I recommend that you do too.

In any case, make some kind of gauge that will allow you to apply the same standard measurement to all your cars without using another car to judge the correct height. If your adapter is the correct thickness, as outlined above, you should see this image when you measure the coupler's height.

And if you positioned the #43 holes so that the Kadee draft gear just overhangs the end of the car, you should have about 1 inch of clearance between two coupled cars. I have found this to be satisfactory for all my trackwork and it presents a pleasing visual image.

 

ADDING BODY MOUNTED KADEES TO USA TRAINS CABEESE

The new USA Trains extended vision and bay window caboose models are a beauty to behold but they present a real problem when trying to body mount couplers.

The area where you would normally put a machine screw to hold the draft gear is a see-through casting that is so beautifully done and so delicate that I hated to mar it with screw heads.

I also wanted to develope a method that would not require the removal of the trucks so that the modeler would not have to unsolder the pick-up wires.

To meet this challenge, I developed another coupler height adapter that fixed the problem.

Through trial and error I found the right dimensions and used a longer adapter style that allowed me to put 4 small 2/56 flat headed machine screws into the underside of the frame of the car in a hidden location. This permitted me to attach the coupler draft gear to the adapter without drilling any holes in the see-through walkway on the end of the car.

 

The USA TRAINS Caboose Coupler Height Adapter

Here is a picture of the adapter before I countersunk some of the holes.

The adapter started out as a piece of aluminum stock 1/4 inch thick and 1 inch wide. I cut it to be just under 2 inches long. I drilled 4 holes on the end of the block with a #44 drill bit to clear the shaft of a 2/56 machine screw. Placing these holes is not very critical except that they need to be along the edges (preferably within .1 of the edge) and no further from the end than 3/4 of an inch. On my piece the two end holes are .1 inches from the end and the side edge and the other two holes are .1 from the edge and .75 from the end.

Next, drill two 1/8 holes on the centerline of the piece at the opposite end from the 4 holes you just drilled. On my piece they are .330 inches and .990 inches from the other end respectively.

Now comes the tough part. I temporarily mounted the Kadee #820 draft gear to this block using the two holes you just drilled and some 4/40 flat head machine screws. Next I traced the outline of the daft gear in the metal.

Removing the draft gear and the machine screws, I then mounted the block in my milling machine and removed material to thin out the place where the draft gear was going to be mounted so that what remained was .10 inches thick.

After this I used a countersink bit to prepare all the holes for flat head screws. For the two 4/40 crews I countersunk on the side that will be the top of the piece. On the four holes for 2/56 screws I countersunk on the other side (the bottom of the piece).

Here is a picture of the adapter mounted on the underside of the car with Kadee #820 daft gear attached.

Here is a picture of the end of the car after the coupler has been attached.

Finally, here is a picture of the walkway showing that it has been undisturbed by my conversion.

 

Testing for Correct Height

Naturally, as with all these conversions, the final step is a check with the Coupler Height Gauge. Since this car sits about the correct height off the rails right out of the box, this adaption method should bring the coupler height right to within specs.

 

Another Approach by Brandy Bruce-Sharp

I normally favor a physical attachment of couplers with machine screws to make sure that the attachment can withstand the significant forces that long trains can put on them. However, in the case of a caboose which only appears at the end of a train, the couplers are only pulling the weight of that one car. In this special circumstance, other attachment methods may become more convenient.

One such method was recenlty employed by Brandy Bruce-Sharp, who should need no introductions since he has also written articles for Large Scale Central.

Brandy made up a special coupler adapter to mount a Kadee #821 shortened draft gear unit. His drawing of the styrene assembly is shown in this image.

Brandy used Cyano-Acrylic glue to bond the adapter to the caboose frame, as shown in this image.

Whether you use my method or Brandy's, the finished product looks great!

 

ADDING BODY MOUNTED KADEES TO ARISTO COVERED HOPPERS

In many respects, beause of some unusual angles, this is the most difficult car we have discussed so far.

Start by removing the trucks and couplers in the usual way. Remember to cut off the tang that holds the stock couplers to the trucks. Now remove the floor from under the body casting.

 

The ARISTO Covered Hopper Coupler Height Adapter

Note that the end of this car includes some angled floors making body mounting of couplers a bit tricky. The spacer that I came up with compensates for the angles and puts the Kadees at just the right height. While I was at it, I thought it might be an interesting challenge to try to include some aspects of an I beam in the casting.

This picture shows the final product from the side, and you can see the lower lip of the I beam shape that I managed to make. Here's another image showing the adapter from the bottom. And lastly, another image showing the adapter from the end.

Needless to say, I copied this part in resin castings and, when mounted on the underside of the car floor it looks like this.

I attach these to the car floor with 2-56 flat head machine screws and some epoxy glue. I then use 4/40 round head machine screws to attach the Kadee draft gear.

When you have the adapters attached, paint them flat black and then assemble the Kadees.

After reassembling the car floor to the body, here's what the final assembly looks like after you have put the car back together.

 

Testing for Correct Height

Reinstall the trucks and test for correct coupler height with a gauge as with the other cars we have mentioned.

 

ADDING BODY MOUNTED KADEES TO ARISTO STREAMLINED PASSENGER CARS - BOTH SHORT AND LONG

This section of this article is still under construction but will be finished soon, so check back for updates after the national convention.

 

ADDING BODY MOUNTED KADEES TO ARISTO HEAVYWEIGHT PASSENGER CARS

This section of this article is still under construction but will be finished soon, so check back for updates after the national convention.

 

I will gladly furnish copies of my coupler height adapters to anyone who wishes to copy them for themselves and will sell limited quantities to anyone who has neither the time or the skill to copy them for themselves.

Well that's all for this session. I hope this article gives you enough information to try a couple of these projects for yourself.

If you have any additions, corrections, or comments on the content of this , or any of my articles, please send them to me at lawrence_d_cooper@yahoo.com.

 

Thanks for your attention. Now get busy!

 

 



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1 comment
  • Dick Friedman
    Dick Friedman Good article but two questions. Where are the links and/or pics? Why no instructions for Bachmann cars?
    January 31, 2013