Metal vs Plastic: Couplers

[Jumijo]

I've noticed that metal couplers are big selling points in toy train manufacturer's advertisements. Some even go so far as to ridicule pieces equipped with plastic couplers. I got to tell ya, I don't get it. All the plastic couplers on my rolling stock I have work far better than any of the metal versions. I find metal couplers to be prone to binding (aren't as easy to close - even after lubing), and require more force to couple together. I'll take plastic couplers that will close when I back two cars together slowly as opposed to the slamming needed to link up metal ones.

So what is the attraction? Durability? Weight?

Jim

[wrmcclellan]

Jaabat,

I tend to agree with you. I have much of my original Lionel from the 50's and most have plastic couplers, they all still work, and none of them broke. I was not kind to them either when I was a kid. High speed ramming/wrecks, high speed derailments, etc., were the order of the day.

BTW - I think the reliability issues of some plastic couplers was due to the modern era plastic armatures letting cars uncouple too easily under load, but not the coupler itself.

[lionelsoni]

Don't plastic couplers date from about 1970?

Aside from uncoupling too easily, there is also the problem of chronic failure of the plastic knuckle spring.

[brianel027]

Lionel started using plastic couplers during the late 1950's if my date isn't mistaken. These were the type with the copper-strip armature.

The drawback to plastic couplers is the knuckle itself. The metal ones have a spring inserted with the metal knuckle (which is a royal pain to put together). The plastic ones have a thin piece extending from the knuckle which acts as a spring. This piece on the K-Line knuckles is thincker and also stiffer than that of the Lionel type, which is why I recommend using the Lionel ones for replacements.

I have had cases where cars with die-cast couplers let go of eachother... the case here is the amount of tension the armature puts on the pin leading up into the knuckle itself. This is easily fixed on the plastic trucks by removing the armature and bending or flexing it in an upward direction. This helps put more tension on the pin going into the knuckle. You can also heat the piece up and bend it that way.

On the early K-Line die-cast trucks, the plastic armature was made of either a thicker or less flexible plastic. The armature has a tendency to become removed from the coupler itself when activated over an uncoupling track. Using one finger, hold the base of the armature (furthest away from the coupler) and gently bend the armature repeatedly. This will help it to operate better... be careful... you don't want to break the piece. I've done this hundreds of times and have only broke one or two, but that's still too many.

On the K-Line die-cast truack when they first when to a all metal assembly, the pin extending into the knuckle was too think. This is one reason for what causes the cars needing to be slammed (the other is the shape of the knuckle in correspondence to the car it is being coupled to). Using a jeweler file, you can file down the thickness of the pin and make the couplers work better.

[ChiefEagles]

Couplers that "let go" under load are fixed with Orthodonist's rubber bands for retainers. My oldest daughter had braces and about the time I got back into trains [after my childhood] she was in a retainer. I used the small but strong rubber bands over the coupler. It holds the [what I call] the uncouple tab closed so the knuckle can not open but will allow it to drop down when crossing an activated uncoupling track section. Just slip it over the knuckle and back toward the "thumb tack".

[3railguy]

The Lionel plastic couplers of the late 50's and 60's with the spring steel armatures have given me little grief. MPC switched to plastic armatures and those gave me lots of grief which I cured with super glue. LTI used metal couplers with plastic armatures. Those are just as bad as MPC. They put the meat in the wrong place. The newest metal coupler design on Lionel's newly tooled scale freight cars give me zero grief. Never had a problem. Atlas trucks have been good too. can't recall those failing either. MTH metal couplers have not been as good but I understand they changed the design to be like Lionel. K-Line couplers were real bad up until recent years.

[Anonymous]

I would like to replace the plasatic coupler on my 783 tender. Strange that the finest locomotive General Mills ever made had that thing. Anyone know of a replacement?

[Anonymous]

I'm glad that the K-Line freight cars with the plastic couplers passed the governments 5 mile an hour front end cra***est,because you do have to slam them at high speed to get them to hook up. What i did with mine is throw caution to the wind & took a drummel motor tool & filed down the whole knuckle assemple. inside & out. It works pretty well now,doesn't require the same force. as before. Easter.

[lionelsoni]

It seems that the Lionel plastic couplers before 1970 had metal knuckles and metal knuckle springs, and that the armature was also metal. I think most of the problems started when General Mills began to make these parts out of plastic.