For close coupling of the Stewart chassis, simply buy the KD #450 set, it will give you the 3’ distance between units and is MUCH easier to install. Thats yet another reason to avoid the Athearn blue box F7 chassis as a method, vs. Stewart on a Genesis shell. Stewart all the way.
I have installed the close coupling kit on an Athearn frame before and IMHO the installation is not that hard on said Athearn frame. Contrary to the mention in another post, the only place where I see I will need to use the Dremel on the basic frame is to remove the front coupler mount. I will need to get creative on the super weight as the train will be pulling at least 16 cars. (I am pretty sure that I will be powering one of the B units as well.)
intermountain regal drives work well too
[I] I had a similar situation but with different brands. I have a complete set of Norfolk and Western coaches but didn’t want to spend the money for engines, although I had to E units that matched my coaches. The E units are Norfolk and Western by Rivarossi but did not run as well as my E units from Proto 2000 of which I have six, one with a new Tsunami 2 Sound decoder which is 2 amps and work great on my DC layout.
So out of curiosity I removed the shells from the Proto’s and then placed the Rivarossi shell on the Proto chassis, including the one with the decoder. The Norfolk and Western shells slid right over the Proto chassis, a good fit by the way, coupled everthing up with the coaches and it ran beautifully. Now I have a six car Norfolk and Western passenger train with two E units and sound. It is very exciting to watch this consist roll, it’s a beautiful sight.
I do have two really nice B+O F units from Athearn but I wanted better chassis. I placed the two B+O units on two Stewart drives and they work great, just to let you know, and they are both as smooth as a Rolex watch.
Robert Sylvester
Newberry and Columbia line
You can fit an Intermountain shell onto an Athearn RTR drive, probably a BB drive also but I haven’t actually tried that combination.
Intermountain casts four wedge clips into the fuel tank shrouds. You must slice these off flush.
The Athearn chassis has two tabs instead of wedges on the shell. These tabs almost fit into the center slot in the top of the fuel tank shroud on each side. The tabs with paint on are 1.0 mm thick and the slots in the shell are a very tiny bit narrower.
I used a #11 exacto to carefully slice a very thin strip out of the bottom of each slot. Leave the top of the slot as is, that locates the shell snugly onto the frame.
I worked in stages to ensure I did not make the slot any larger than it needs to be. Ideally the shell snaps on tightly.
So, I stumbled on to this thread looking for experiences with this very topic
In my case, I have a fully powered stewart/Kato a and b, but I have a shell only for another a to complete the a-b-a setup. So for me, I’m looking for it to be a dummy and so finding a $50 Kato drive or even just the frame seems a little overkill when the athearn frame and trucks can be unpowered just as easily.
And I have a bunch of frames.
What I see when try to mate these is that the start shell is just physically narrower. The athearn frame is too wide to clear the sides of the shell.