Just to re-activate this thread a bit:
Like probably most of you, I have several "conversion" cars equipped with different couplers on each end. Mine are a T&P gondola with knuckle on one end and a link-type at the other. I also use an IC boxcar with knuckle and a KD HO scale coupler...wait, what? "HO scale"?
Yes. In my quest to find the ultimate "sweet spot" coupler wise, I complicated things a bit when I purchased this; you may remember my posting it:
Since this is (kind of) a "scale" model, I just was not happy with those link couplers...
Not long after, I also picked up a couple of "Midgage" cars, which I also posted and discussed mounting these on one of the cars:
Since I have quite a few of these left over from my old HO scale days, and they are "era appropriate", I've decided to use these on (at least) some of these "scale" models. Now, how to tie everything in together?
As it turns out, the shaft width of the KD O scale coupler (mentioned much earlier in this thread) is almost exactly the width as the coupler box of that almost universally used HO scale coupler, the #5; so it (the #5) fits perfectly into the mounting tabs of a Flyer truck. Here is a photo of a link, knuckle and a truck with an HO scale #5 mounted:
I did have to cut off the extra mounting "ears" off the #5 box to get it to fit, but that's no big deal.
I'll admit that perhaps these HO couplers look a little small, but the good news is they will mate with both the KD S scale and O scale couplers, so how can you go wrong? 
So where I'm at now is this; here's a Flyer #302AC and the IC boxcar, both with the #5s:
Here is that old wooden boxcar, coupled to a "Midgage" car, both with the Roundhouse couplers:
...and here is that same wooden car, this time coupled to the #302 with KD coupler:
Now I can run pretty much any combination I want: link, knuckle or any one of several types of HO couplers.
I promise I will never post another thing about couplers...I promise!
Mark in Oregon
