I had two objectives in mind when starting a post over on the 3RS forum. One was a better way to mount Kadees on AtlasO cars in a manner that the pocket's location relative to the car's end sill was consistent with prototype practice. Mounting Kadee pockets using the existing Kadee and Atlas holes typically results in the pocket protruding beyond the end sill - not enough for a cushion car, too much for a non-cushion underframe car. I learned that Mario's 3D printed AtlasO mounting adapter/shim nicely satisfies this objective.
My second objective relates to improving the appearance of freight cars by offering an alternative Kadee draft gear pocket with a near prototype width on its face.
Left to right in the photo above are cars with AtlasO, Yoder, and Kadee coupler pockets. The AtlasO and Kadee pockets have .45" interior width openings at the face. The Yoder lost wax brass pocket opening is .30" wide. IMO the narrower pocket look noticeably better. I've operated narrow pocket cars over 42"r on curves on my previous railroad (51" on my current mine branch) without issue. What is lost with narrow pockets is Kadee's delayed coupling feature which requires a wide coupler swing to misalign the coupler heads when cars are positioned over a fixed magnet. I believe a narrower Kadee mounting pocket would be a viable option for most 40'-50' cars on layouts with modestly tight curves.
Whether the shimming/mounting feature should be one piece with the narrow pocket or separate pieces is an interesting question. I believe separate pieces would satisfy the widest audience - but with the flexibility of CAD and 3D printing perhaps customers could be offered both options. I wonder how many O scalers would be interested in equipping some or all of their freight cars with better looking Kadee coupler draft gear.
