Kadee Body Mounts for Aristo Heavyweights

Kadee makes specialized components for body mounting Kadees on these cars.

Initially I just threw the truck mounted couplers on these cars, and I was having uncoupling problems behind my new E8. The couplers just rode over each other. What helps make this much worse is that the design of the Aristo 3 axle truck is such that pressure/weight from the body is not evenly distributed fore and aft since the pivot point is not in the center of the truck.

This causes the truck to be way out of level. Also, the long coupler tang has too much leverage against the truck and it's springs. 

The result is excessive travel up and down of the coupler.

So I decided to try the Kadee body mounting system, even though I have some sharper than hoped for vertical transitions.

(Being body mounted, the coupler "attitude" is not from the coupler tang on the truck, but the overall attitude of the car, which should be worse)

The bottom line, it was worth it, and works better everywhere. The reality is the consistency of the car attitude is superior to the up and down motion of the long coupler tangs and the weight distribution problems.

I decided to try this out on the first car in my train, the RPO car, which is one of the two new cars Aristo has started making (the other is a full baggage car).

The Kadee solution:

The Kadee parts consist of:

The way it works, there is a square recess at the end of the car. You cut the old coupler tang off, screw the bracket to the coupler housing and then to the shim, and the whole works is glued into this square recess.

Not so fast! Aristo changed the underbody of the two new cars, the recess is gone, and you have to cut away part of a plastic crossmember to do it. (Thanks a lot Aristo!).

You also need to notch one side of the shim, because you need clearance there too!

To mark what to cut out, measure from the leading edge of the diaphram back to the back of the shim, exactly 2 inches.

Then mark the crossmember with the angled end of the shim, and then cut it away, I used a carbide bit on a dremel.

Notch the other end of the shim to clear the end of the car, and the whole thing sits in place. Kadee says to glue, but use a number 44 drill (.086") through the two holes and use Kadee 2-56 screws and nuts to secure it. These are the long ones that come with Kadee 830's.

The picture below shows the assembly in place:


 

And, instead of gluing, I was able to use screws, you can see where they come up through the floor inside. They are the two screws in the center in the picture below.

This works ok, but I think it is not the best solution.

  • You don't really need the flex bracket for 8 foot diameter and above
  • It does not provide close coupling
  • The "slack action" coupler is really a poor choice for passenger cars and close coupling because of the in and out movement of the coupler forces you to increase car to car spacing.

Better solution:

I looked for a way to use the spacer block #881 with a fixed coupler mount.

The 830/906 is not a solution if you want close coupling, the coupler box would hit the truck.

I found that a center-set coupler was pretty good spacing, height and setback in an 831 housing.

Here's a picture of it in a car:

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So the mount is pretty simple, below is the mockup:

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I decided to put the screw heads inside the block, so you have to mill down the inside a bit so the screw head is flush with the top of the block:

look carefully.

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For the observation car, I used a "T" bracket just like Ted did, but since I cut off my plastic bosses and put screws through the holes, I just put holes in the bracket to match my screws, which are exactly 47.5 mm apart.

Then my 3mm truss head screws will go through the bracket.

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