Body mounting couplers on 89ft flatcars

[BigLocosForMe]

To try to improve the tracking of some Micro Trains 89ft flatcars I've got, I'm planning to remove the existing sort-of truck mounted couplers and replace them with body-mounts. What I'm wondering though, is could I potentially get away with, rather than drilling and tapping the flatcar and using screws to mount the couplers (as indicated by Micro Trains directions,) could I instead use just a dot of CA?

Or, would I be risking getting CA into the coupler itself and rendering it non-functional as well as almost non-removable?

[WP&P]

Even if the CA is successfully applied, I would worry about the long term viability of that approach. With the screw, all of the forces acting on the coupler get transmitted into the body by means of a mechanical connection. With the glue, you're applying shear forces to a glue joint that could break at some point.

Maybe there is some way to fabricate a harness that grips the coupler box, made out of thin brass or aluminum sheet perhaps, so that the harness can have a big surface area for glue contact.

Also, for such a long car, maybe it would be wise to use a long-shank coupler and set the coupler box recessed a bit, so the coupler face has more side to side movement.

[BigLocosForMe]

So the couplers I'm thinking to use are the ones that are currently on the cars: https://micro-trains.com/index.php?r...product_id=326
Getting them off the cars will require snipping the "arm" that goes from the coupler box back to the fingers on the trucks. I figure I can snip it off without completely trashing the coupler box then it's either a smidge of CA or try pushing out the pin that's in the coupler and replace it with a screw.

My main concern with using the screw is, drilling into the underside of the flatcar.

[MRLdave]

Not sure what you are meaning by "tracking ability". But body mounting couplers on long cars can often DECREASE tracking ability, especially on tighter radius curves. You actually lose articulation and the couplers will torque the car off the track. (why WP&P suggests going to long shank couplers) when it reaches its limit. It WILL help if you are backing the cars a lot, if that's what you are refering to when you say "tracking ability". And if you have large radius curves, it certainly is more prototypical to body mount. But body mounting isn't a fix-all , so if you try, since it sounds like you have multiple cars, I would just do one car, and see if it solves whatever problem you are trying to fix.
Flatcars are a special problem for body mounting......with a boxcar, if the screw sticks thru the chassis, it's hidden inside the car.....with a flatcar it's hanging out for all to see. And the tolerances you have for drilling deep enough to give the screw a decent bite, and drilling thru the car are pretty minimal. In theory the glue should work, and if it fails, it isn't any worse than an uncoupling, but again, I'd do one car and do some testing before you proceed with the rest.

[donzi]

I agree with @WP&P

Tensile strength in a Shear force direction is not a strong point of ACC adhesives.
I've mucked several couplers up by accidentally getting ACC in the box attempting to glue lids on, now I melt them on.

What about a UV cured adhesive applied as a filet around three sides of the coupler box?

[BigLocosForMe]

if you are backing the cars a lot, if that's what you are refering to when you say "tracking ability"

So because of my limited space, there is quite a bit of backing, and worse, a couple of the curves are on the tight side. It's on an Ikea table top, so just a hair under 24" deep, so the largest curves are around 11" radius or so (KATO Unitrack) So I don't really have room for "pull through" sidings, sadly...

I'm thinking I might go for the CA on one car, if it shears off, I can either clean it up and re-glue it, or see if I've got enough room to use a screw without punching through the deck of the car...

[Army-Gandydancer]

I have some 68' DODX flat cars with body mounted couplers. The corners of the cars will hit when backing up on any curve less that 11". The cars in question are Micro-Trains DODX flat cars. They do okay on 11" curves but still want to tilt and derail when backing up.

[MetroRedLn]

I personally would not recommend body-mounting 89' cars if you have a minimum radius of under 15". You're going to have derailments galore. Either live with truck mounts or find a way to accommodate larger-radius curves.

[Heiko]

To try to improve the tracking of some Micro Trains 89ft flatcars I've got, I'm planning to remove the existing sort-of truck mounted couplers and replace them with body-mounts. What I'm wondering though, is could I potentially get away with, rather than drilling and tapping the flatcar and using screws to mount the couplers (as indicated by Micro Trains directions,) could I instead use just a dot of CA?

Or, would I be risking getting CA into the coupler itself and rendering it non-functional as well as almost non-removable?

I'm pretty certain you will be able to remove remains of the coupler, even if you mess it up - CA is not that strong...

Now I don't know those particular cars, but I usually prefer drilling holes, especially in metal frames. Can you remove the deck before drilling? Or add a new deck afterwards?

I have on some cars added small drops of CA along the sides of the coupler box sides to avoid the coupler box swinging around the screw (to avoid overtightening the screw...). I did so by dripping CA on a piece of scrap wood and transferring tiny CA droplets with a pin, very carefully to avoid glue running into the coupler mechanism.

Heiko

[pbender]

CA can certainly be used to hold couplers on cars.

I haven’t used that trick on MTL 89’ cars, but I have used CA only to hold couplers onto red caboose flatcars because I didn’t want to see the screws through the deck. That has worked out fone for the most part… in almost 20 years of thoee cars being that way, I’ve only had to reglue couplers once or twice.

Paul

[NtheBasement]

Another warning here that the geometry of the situation is going to make body mounting worse than truck mounting. Not just due to the length of the cars, but my 89 foot flats also have a long distance from bolster to end of car. That will cause the coupler to swing even further to the outside of the curve.