I have some F7 that go back 30 years, and their coupler system was flimsy then, and today is still the same. Besides the flimsy little plastic cap that’s supposed to hold the coupler, both in the front and the back, they hang out way too much. Did anyone ever come up with a way to improve this system?
much appreciated
Mill/tap/Kadee Box
David B
That’s the answer. If you don’t want to even this little bit of machining, you could glue a Kadee draft gear box to the frame, but that would make it hard to ever take the shell off again.
Use a number 5 or 58 for the rear. The cab end needs a longer shank coupler to clear the pilot, but Kadee makes those, too.
American Limited also makes a close-coupling adapter that clips into place. It’s much easier to do than the mill/drill/tap method, though probably not as strong. It’s part # 6100 for a 6-pack of close-coupling adapters by themselves, or they sell them with diaphragms and spacers specifically for the Athearn F-units.
On my F7s (which are incidentally currently in for a new paint job), I’ve installed Kadee #27s on the nose of the A unit, and #7s on the rear, and on both ends of the B units. Mine were mounted in the Kadee boxes–drill out the little ‘hole’ on the pad with a #50 drill, and tap for a 2-56 screw.
Check the Kadee “what fits what” list. It will give you the number of a Kadee coupler that comes with the little round coupler box. The box mounts with a 2-56 machine screw. You have to drill the coupler lug on the Athearn frame and tap it 2-56. I use a drill press which bores thru the frame rapidly, but you can do it with a hand held pin vise, just takes a little longer. You want to make sure the coupler is insulated from the hot chassis to avoid shorts when double heading. If memory serves, use of a nylon 2-56 screw (included with the couplers) is sufficient to keep the metal coupler from contacting the hot chassis.
That is the most simple solution. Drilling a hole and tapping it not even close to being hard. Don’t use a standard Kadee box on the rear. it sticks out too far in the back and can interfere with the rear truck. Use one of the shallow rear #30 or #20 series couplers. I prefer the #30 because the rear of the box is not square (saving even more space).
The mill/tap/Kadee box worked well for me on my Athearn F7’s. It’s been awhile, and those units have not been converted to DCC. I believe I used a #38 on the rear; but am coming up blank at the moment for what I used on the front. (Is this a senior moment, or just getting in from the job and too much multitasking going on)?? One of the above posters mentioned a longer shank coupler for the front, which sounds right. I’ll return and post that coupler number when (and if) the fog in my brain clears.