Large Scale Central

Kadee 906 conversion step-by-step

Modeling Technical Modeling
#1

I posted a 3D file for a 906 adapter for USAT/LGB rolling stock with the link and pin pockets, and was asked for a step by step demo. I’ve refined the adapter so it can be either glued or mechanically fastened. Gluing is desirable for flat cars where you don’t want screws poking through the deck.

Here is the adapter:

The flat side goes toward the car, and the little notches are used to center it.

Step 1: Confirm draft gear box height

On most of these cars, the gauge lines up with the top of the link and pin pocket opening.

Step 2: Cut off the bottom of the pocket

I forgot to take a photo, but you can see it below.

Step 3: Remove the frame and cut out the two interfering beams

Before and after:

Step 4: Mark the centerline

It’s generally 2" between the remaining frame members. I use a flexible 1" ruler and lightly score a line with an Xacto.

Step 5: Slice lip off gear box cover for flush fit

Before and after:

Step 6: Dry fit the gear box and mark the location

I put the screws in finger tight and line up the box with the back edge of the car. I mark how far back the adapter lands. Centering is done in the next step.

Step 7: Line up the adapter using the notch and window to center it on the score mark, and glue it down

Step 8: Screw coupler assembly to adapter.

  • Use 5/8" screws if you don’t want to go through the deck.

  • Use longer screws and pre-drill pilot holes if you do.

#2

Here’s the final result (I guess I hit a limit on the previous post):

And the thing: https://www.thingiverse.com/thing:2591494

#3

Very nice. Can these be purchase?

#4

Oh man, thanks for that.

#5

Louis Sommers said:

Very nice. Can these be purchase?

I’m not super interested in getting into the business of selling parts, but I’d be willing to print a bunch and distribute them at cost.

An alternative is to use the same process, but use 1/4" nylon spacers with washers instead. This only works on a car where you can screw into the platform, like a box car or reefer. That’s what I did before I had my 3D printer. Here’s a photo of a USAT woodside reefer. In this case, I also modified the draft gear box to retain some of the details on the coupler pocket instead of just shearing it off.

#6

Unless you have super wide curves, your wheels will grind against the KD, making that type of body mount useless.

#7

Ten foot diameter curves are the minimum… (5 foot RADIUS)

#8

They are fine down to a little less than a 4’ radius.

#9

You can do the same modification using Styrene shims…but those spacers do look nice, for those that don’t know how to work with sheet Styrene.

#10

Yes, Eric…you can go down to that minimum, but I wouldn’t recommend it…nice work, BTW…

#11

Fred- thanks. I wasn’t arguing with you; we responded simultaneously. i did all my testing on some 4’ USAT track, and didn’t have any issues. I have one curve in my basement that’s a little tighter, and they just barely rub. I ground a little material off of the screw posts on the geraboxes on one car, and that solved the problem.

Mod course if the curve gets much tighter, they won’t stay coupled anyway.