Help with a Kato coupler spring?

[Maletrain]

I just received a Kato F-7 A-B set and tested it.  All works fine, except there was a loose spring in the box, which inspection showed had come from one of the couplers on the B unit.

I have tried to reinsert that spring for a while, and seem to be at a loss to get it into any place where it will stay.  I thought I had it a couple of times, only to have it pop out and make me play go-find-it-in-the-carpet, twice.  (I won that, both times.)

So, now I am out of ideas, even though I am not out of springs.

I am wondering if there is something wrong with the coupler or box that is the reason the spring was out when I got it.  If so, it is probably useless to keep trying to put it back.

Any ideas or experience that others have with Kato springs would be appreciated.

At this point, I am thinking of just cutting the box off the truck and body-mounting a MicroTrains coupler.  It is on the end I would couple to a train, anyway.

[peteski]

So it is the coil spring for truck-mounted coupler (not the thin leaf spring for a body mounted coupler)?  Those flat ones are a pain to deal with. You should be able to put it back where it belongs.  I just did this on my F3.  Mine is from the current run (not the original split-frame model), so I'm not sure if yours will be the same.

Unfortunately the truck has to be removed from the chassis.  I pull off the loco's shell (2 sharp toothpicks are needed at the latch areas). Then I unlatch the plastic worm bearing and electric pickup insulator on both sides and raise it slightly to gain access to the truck's latches.  Don't push it up too high not to bend the pickup strips. Then using a mini pry bar (I made from a broken dental tool) I slightly pry out the truck mounts until they pop off the chassis latching tabs. I do this on both sides.  Then the truck just drops out of the chassis.




Next thing to do is to unsnap the coupler box cover. I again use my little pry bar. Then I use use tweezers to pull the cover off.  The coupler will stay in the box which makes things easier.



If you hold the truck with the coupler dangling down, there is plenty of room between the back of the coupler shank and the spring retaining post to slide the spring back in. 



While holding one end of the spring with tweezers slide the other end over the post, then tuck the end held by the tweezers behind the back of the coupler shank.



Once the spring is seated, push the cover back on. Notice that the the back side of the coupler box cover has sharp wedges so  when it is reinstalled with the spring in the coupler box, it should easily wedge itself behind the spring.  Pretty ingenious.

[Maletrain]

Thanks Peteski!  Your pictures also were enough to show me that the parts on mine don't seem to be broken.  (So I am wondering how in the heck the spring came out of there in the first place, before I received the loco.)

You said you just did this with a Kato F3.  If this a common problem with Kato couplers?  If I put the spring back where it belongs, is it likely to just come out again?  I haven't had this problem with other Kato stuff, but I know they change things, and, frankly, I have not run the other stuff as much as I would like to, yet, either.

[peteski]

I have never encounter fallen out spring on those couplers.  I just did the procedure for you. I did not try to yank the spring out to simulate it falling out. I Started with a functional coupler, then took it apart to remove the spring, then reassembled it while taking photos of the process. 

I would think that it is extremely unlikely that the spring fell out on its own.

[Maletrain]

Oh, Thanks for doing that.  I thought you were saying you did it because you had the same problem.

So, yes, it is a mystery why I got a B unit with a separate coupler spring sitting in the box, no where near the coupler. 

I guess I will try to take it apart and put the spring back.  But, frankly, doing that twice seems like more work than replacing with a MicroTrains coupler the first time.  So, I will probably try to see if there is something wrong with this coupler when I take it apart. But that won't be today.

Anyway, thank you for your effort on my behalf, Peteski.

Edit:  Plans changed, so I did work on it today, followed Peteski's directions, and got the spring in (and the loco back together and working).  The coupler does work and the spring does not fly out when I put some pull on the coupler. So, I guess this is success.  But, the spring does look a bit out of OEM configuration after getting snagged a couple of times, and I had to reform it a bit. 

Thanks again Peteski!

So, if that spring comes out again, I will put a MicroTrains coupler on the body.  Any recommendations for which MicroTrains coupler?  I'll probably go with the N scale versions instead of the Z version for this application (heavy load, no switching), but it does look like a Z would fit more easily. 

Recommendations?

[peteski]

If you want to change couplers then I recommend using a short T-shank Precision Masters Unimate coupler sold by Red Caboose. They are currently owned and sold by FVM. While non-functional (as far as uncoupling goes, they will give you close coupling between locos.  Makes a big difference visually.

EDIT: Corrected info about Unimate couplers.

[Maletrain]

Peteski, I have used a lot of those T-shank, dummy knucKles on old cars that came with Rapido couplers.  My problem with them is that they tend to droop a bit and sometimes uncouple when running trains at my club (with not-so-perfect track work).

So, if I have more issues with it, I will probably replace the Kato truck mounted coupler with a MicroTrains body-mounted version of some sort, tapping into the metal fame for a 00-90 screw, because I don't expect CA or epoxy to hold reliably on a MicroTrains Delrin coupler box.

But, the space for a coupler box look bit tight by the Kato trucks when the Kato box is cut off the truck.  I expect others have done that, so I am looking for whatever they learned and can provide as advice for what to use or what to avoid.

[peteski]

Peteski, I have used a lot of those T-shank, dummy knucKles on old cars that came with Rapido couplers.  My problem with them is that they tend to droop a bit and sometimes uncouple when running trains at my club (with not-so-perfect track work).

So, if I have more issues with it, I will probably replace the Kato truck mounted coupler with a MicroTrains body-mounted version of some sort, tapping into the metal fame for a 00-90 screw, because I don't expect CA or epoxy to hold reliably on a MicroTrains Delrin coupler box.

But, the space for a coupler box look bit tight by the Kato trucks when the Kato box is cut off the truck.  I expect others have done that, so I am looking for whatever they learned and can provide as advice for what to use or what to avoid.

When installing the T-shank don't use the spring, and instead glue a piece of styrene to the back of the "T". That will fill the side openings in the coupler box and prevent the coupler from drooping.  Yes, the coupler will not be able to swing sideways, but that doesn't seem to cause operational issues, and no more drooping.  I don't remember the thickens of the styrene strip, but just pick one that will fill the remaining space in the slot.

And yes, the lack of space for a coupler behind the truck is one good reason why many modelers don't body mount a coupler.  But if you want to go that way, maybe someone will chime in with their installation procedure.  But it will likely not close couple like the T-shank coupler in the truck.

[Albert in N]

   Loved Peteski's precision photos and comments.  I am glad Maletrain started this thread since I own quite a few N scale Kato F units.  My newest is a Santa Fe passenger B unit from the last run; and it had a coil coupler spring missing when it arrived (was brand new).  I had some from an earlier Kato parts order and installed it and no further problem except for too wide spacing between units.  I have installed Fox Valley dummy couplers on four sets of my F units and pleased with the spacing and operation.  Of course I left the factory couplers on the nose except for some noses with Micro Trains Line coupler replacements. The trick is to use short or medium shank Fox Valleys at your preference.  You will have to lightly clip off the edges of the T shank to get it to fit into the Kato truck coupler box (Fox Valleys are too wide to fit otherwise).  Also, you will need to clip off about a third of the Kato coupler spring post to get the Fox Valley with Kato coil spring to fit.  I have also used Micro Trains Line conversions on one set and they are a pain to convert except for the nose end of an F, plus they have only a slighter unit space improvement over the factory Kato couplers.  Currently, I have an ABBA Santa Fe passenger set that I have not decided on converting (at least the factory Kato couplers work well and the spacing is not as bad as some competitors like Bachmann Fs).  Also, the Kato factory couplers look more realistic since they are smaller.  Here is a photo of my freight Santa Fe AA set with Fox Valley rear couplers.

[nkalanaga]

The Red Caboose couplers were originally called Unimates, made by Precision Masters.

[peteski]

The Red Caboose couplers were originally called Unimates, made by Precision Masters.

Thanks!  I edited my original post.

[nkalanaga]

I used a lot of them on my Kato Fs, all of which are early-run units, and came with Rapido couplers.  The fronts of the As got MT conversions, everywhere else I used short-shank Unimates.  The BN mixed-and-matched these with almost anything, so I needed knuckle couplers, but not working couplers.  The Unimates shortened the coupling distance nicely, and can still be hand-coupled with MT-equipped units.

Actual consist, in Pasco, in 1977 or 1978:  A-B-C415-B-A.  At that time, the Pasco roundhouse looked more like the late 40s or early 50s than the late 70s.  Fs everywhere, and very few modern units.  I saw freights with up to seven Fs, all in BN green.