I own a couple of HO brass F-7 locomotives from various importers, mainly OMI and CIL. Unlike recent plastic models, brass locomotives have no provisions for prototypical short coupling, and there are no after market parts to be had. By drilling, tapping and soldering I finally managed to change a Kadee #4 coupler into something that does seem to do the trick - well, almost, because it lacks spring action. What do other modelers do in order to get close coupled F-7 units, preferably with Kadees? Challenger’s instruction that come with their models are no help, because there’s still a far too large gap between units.
You can always alternate short and medium shank couplers.
I don’t think any brass diesels come with NO holes drilled/tapped for coupler mounting. The choices I’m aware of are the two-screw mounting style or the single-screw. If it’s the former, this might work:
http://www.walthers.com/exec/productinfo/224-8
It’s obvious what its “trick” is.
If it’s the latter, Kadee, as you know, offers several shank lengths. Are ALL of them too long?
Neat that you still have a #4 around!!!
The correct spacing between end walls of EMD F’s is 3’. It actually looks too big to me, but it’s not. Or, so says the Great Northern Railway and Kalmbach Publishing. You might be trying to couple them too closely.
And then, lastly, I note that you didn’t say anything about the truck gearboxes crowding the coupler mounts. Cutting the back of the coupler box off is usually the solution. Unless it’s not.
And that lack of a centering spring? See Sergent couplers. It’s all the rage.
Ed
The Kadee #30 series box is actually the shortest, The #33 short centerset will usually allow for 3ft spacing and still clear the trucks. I find the tortion springs to be cumbersome/ tricky to work w/ initially, but do give the best coupler action and centering of any of the other draft boxes. The #33 box (short centerset) Will position the coupler height pefectly as long as there is 29/64ths (rail to top of box mounting on pilot) placing the lid on top. These 30 series boxes allow quite a bit of flexability as they can be inverted. Allsorts of arrangements for coupler height can be done w/ box position and
LION uses drawbars instead of couplers on close coupled locomotives. Even a four car unit can be picked up by hand. Well, both hands. My subway cars are six units long, all connected by drawbars, I build a little tool to pick it all up as a single unit.
Also it allows you to wire them together for better pick-up. 48 wheel pick-up anybody.
ROAR
I just figure how close the two units need to be, based on the diaphragms and spacing needed to go around curves, and then make a drawbar out of styrene the right length. These Stewart FT’s are very close to each other, but will take a 22" radius curve…
As Bob mentions, the 30 series are nice and short and work well for F units.
Kadee has an item (252) that lets you use one of their new whisker couplers in a 30 style box. Basically the 252 is a 30 series box without those annoying torsion springs.
For my Athearn Genesis F units I use the #252 boxes, #158 for B unit couplers and A unit rear couplers, and #156 for A unit front couplers.
Accurail makes dummy couplers with a non-moving head that’s almost exactly the same size and shape as a Kadee coupler. They have a pretty short shank, so would cause the units to couple pretty closely. If you don’t plan on coupling / uncoupling a lot, but want the option to be able to separate the units, that is an option. (The dummy couplers will couple with Kadees, or at least if you get them coupled to a Kadee they stay coupled with no trouble.)