Knuckle Couplers

Knuckle Couplers

This article was written specifically in answer to some HO questions.
However, these basics apply to other scales.
(The photo descriptions are at the bottom of the page.)

Q) I want to use Kaydee couplers. Do I just throw out the old couplers and put the new ones on?

Tools for the Conversion A) Kadee (not Kaydee) couplers are the way to go as far as I am concerned. I converted many years back and have never been sorry. However, I did NOT convert everything I had overnight. As I had a fair amount of horn-hook couplers, I created two 'transition' cars that had a Kadee on one end and a horn-hook on the other. I also did the same with one caboose. That way I could have locos and cars with both types of couplers. In point of fact, I did throw away all of my old couplers as I replaced them with Kadee's. The knuckle coupler looks so much more realistic than do the horn-hook and they can be magnetically uncoupled.

Click for larger viewIn most cases, the Kadee and flat spring will fit right into the coupler pocket of the car or locomotive. There are some cases where they won't fit right and I would suggest removing the molded on coupler pocket and replacing it with the one that comes with the Kadee's if necessary. I use the Kadee number 5 almost exclusively although there are a number of coupler models now that are designed to fit various applications where the pocket may be too high or too low or they might need to be plastic rather than metal. You can see a list of couplers and applications on the Kadee website.

Horn Hook Coupler on a car I would like to point out that there are other knuckle couplers now available and some cars and locos come with them already installed. I have tried several, but still prefer the Kadee. However, if you buy a car or loco with Kadee compatibles already installed, you might want to leave them in place until and unless you have problems with them.

I have just bought some of the new 'near scale' number 58s and have installed them on a couple of cars to see how well they couple up with my other cars. So far, they work well and look better.

Q) Do I want delay uncouplers or the regular uncouplers and what's the difference?

Open the coupler pocket Well, that is your choice. You don't even need uncoupling magnets if you don't want them. A Fondue spear or something similar that comes down to a point will slip right in the couplers and a twist will uncouple them. There are also uncoupling tools marketed by two or three companies to help you do this manually without magnets.

That said, I use the delayed uncoupler magnets at key spots in my yards. The delayed magnets will permit you to back onto the magnet and stop. Take slack, pull forward and then back into the coupler and push the car(s) to where they need to be without recoupling. You can place a delayed uncoupling magnet at the lead to a yard ladder, uncouple and push the cars into sidings or even toss them slightly and let them roll. You can't do that with the regular magnet or with a Fondue stick. :-)

Kadee Spring in pocket I recommend the delayed. Be sure to put some kind of marker or sign by them so that you know exactly where they are so you can spot the couplers over them for the best results.

Q) Now, what is the physical difference between a delayed uncoupler and a regular uncoupler? Isn't the uncoupler simply a magnet just strong enough to pull down the fake brake hose on the coupler?

The 'Glad Hand' has to be moved sideways to uncouple, not down. The best way to describe this is that the regular will only uncouple when you are over the magnet and if you attempt to shove the cars back, the couplers will re-couple. The delayed magnets shift the knuckle off center staying there allowing you to push back without re-coupling. For a few cents difference, get the delayed. Both sit on the ties. The delayed is a little wider than the regular.

Aligning the coupler height Are they 'just magnets'? No, not at all. As I mentioned, the 'glad hands' aren't pulled down, the couplers are pulled apart. You can't do that with a regular magnet. Also, Kadee also has stronger magnets for placing under the track and a real super-magnet that some people mount on a movable arm under the track so that cars will not uncouple unless you want them to. They also have an electromagnet for the same reason. But I have found that if you are experiencing accidental uncoupling over the magnet, you probably have something wrong. The glad hand is dragging or a coupler is too low or the magnet is actually above the rail, etc.

Mate! By the way, get a Kadee coupler height gauge and set the coupler height and glad hand position to it. Do this for any of the knuckle couplers that mate with the Kadee. Kadee has a couple of sizes of small washers, which can be used to raise a car on its trucks and you can always shim the coupler down slightly if it is too high. Getting the coupler at the right height is very important no matter who's coupler it is.



Note: (although not rolling stock) The standard Athearn diesel locomotives use the frame as one polarity of the track power to the motor. If you are going to run those locos nose-to-nose or tail-to-tail, it would be wise to use the Kadee's with the plastic shank in those to avoid possible shorts. The #28 is a straight replacement for the #5. I have never had a problem with this but others have. (Of course, I seldom ever doublehead so I wouldn't have this problem.)

Photos: Digital photos by Roger Henlsey
1) Conversion Tools, Kadee #5 Bulk Pack and insulated washers. 2) Kadee 5 parts. 3) Horn-hook (x2f) coupler on car. 4) Car trucks and coupler pocket cover removed. 5) Kadee #5 coupler pocket spring installed. 6) Car reassembled and testing coupler height. 7) Coupler mated.

Page last updated May 22, 2001