I built an entire railroad and figured the radius on 18" using hook/horn couplers on my Athern passenger cars. Since then I have purchased a lot of cars with Kaydee knuckle couplers that won’t make the tight curves. Is there a Kadee coupler that matches an athern horn/hook in length or how do I convert all the Kadee stuff to athern. I am ASSUMING that the Kaydee couplers are #5 but really have no idea what model they are. I have thousands of people waiting on the platform for the train but they can’t get on because it can’t get there without falling off the rails.
I really dont think the Kadee couplers are the problem. I have some curves at 18 degrees and find Kadee #5s perform just fine. In fact, I find that I need usually to switch out the mfg supplied couplers with new car purchases to Kadee #5s to avoid uncoupling problems on curves.
You are really pushing the limits by running passenger cars on 18" R. First you must make all couplers either truck mounted or body mounted. Truck mounted will take a tighter radius pulling but may give trouble when pushing during switching moves. Also, a long road locomotive equipped with body mounted couplers may pry a car with truck mounted couplers off the track.
Check Kadee’s web site http://www.kadee.com/index.shtml for truck mounted couplers to replace those of various manufacturers and for a body mounted swing bracket they make to enable body mounted couplers to work on tighter curves. (It will allow 36’ box cars to operate very well on a 6" trolley radius.)
I have had little luck with the swing bolsters that come on some HO passenger cars. The ones with an arm and plastic centering ears often suffer from fatigue of the centering ears. More than once they were fatigued from their position in the packaging before I opened the box.
The ones with a pivoting coupler box linked to the truck by arms is a nice idea but not built with the precision needed to keep the couplers at the right height or precisely centered for automatic coupling.
Eighteen inch radius is better suited to a logging operatrion, a trolley line or prototypes of the later 1800s. If you really want 20th century big-time passenger operation, you may be more successful rethinking your design.
As the others have indicated the problem is probably not the coupler but where the coupler is mounted. Athearn passenger cars have the hooks mounted so that they swing with the wheels. I am guessing some of the others you have purchased have the hooks mounted on the body.
Truck (wheel) mounted couplers follow the curve of the track. Body mounted couplers will swing out. The tighter the curve the worse the swing. This swing will cause derailments. The longer the car the worse the swing. Hooking two cars of different lengths together can cause derailments. Mixing truck and body mounted couplers will cause derailments.
It would be good to choose one or the other.
If you have tight radius curves and long cars then all truck mounted couplers would probably work better. That could be difficult though, depending on the exact cars you have purchased. It is usually easier to convert to all body mounts. Then you have to start learning all the tricks to make them go through sharp corners.
Kadee #5 will drop into the Athearn passenger cars. They work far better than horn-hooks, or those cheap junker knuckle style things newer Athearns come with.
Do you have other passenger cars with body mount knuckle couplers, or is it freight cars coupled to passenger cars giving problems? The only Walthers passenger cars that might go 18" curves OK are the 60’ heavyweights. The longer ones are going to give you problems.
Does anyone still make trucks with coupler mounts?
I’ve got some very old wood passenger cars I’d like to restore, but they’d never make it around my 18-inch curves with body-mount couplers. Truck mounted couplers would be an option, but I don’t think I’ve ever seen them.
Does anyone make the swinging body-mount coupler systems as an add-on, or are they only available as part of new cars?
Athearn heavy weight passenger cars go around my 18" curves, no problem. I retained the Athearn truck mount for the couplers, installed Kadee #5’s and no sweat. The Athearn cars are “selectively compressed” (short) but they look good and even stay on the track coupled to shorter 50’ milk cars. For that matter, I can run 80 foot IHC passenger cars with body mounted #5 couplers on the same 18 inch curves.
Couple of things help running long cars on 18 inch curves. Make all the cars in the train the same length. Short cars or locomotives coupled to long ones can cause trouble. Don’t mix body mount and truck mount couplers in the same train.
If anything the Kadee couplers are better at staying on the track that the horn-hook couplers. The horn-hook jobs exert sideforce on the cars which the knuckle couplers to not. I’d check the standard things for derail problems. Coupler height, gladhand height, free movement. Wheel gauge, track gauge, dirt on wheels, trucks that fail to swivel properly. Track faults, kinks, improperly seated rail joiners.
