I have a small 3.5x5.5 layout, which I usually use for operating my British trains but occasionally I like to run my North American HO stock on it. It seems that my (generally smaller) British trains can cope with its 15"R curves better than my North American ones. The knuckle couplers on many of my coaches don't like these tight curves & often uncouple. Just wondering if I should switch back to the more reliable hook & horn couplers, even though they're less realistic? I'm tired of experimenting with different kinds of Kadees to find ones that work.
Thanks,
Rob
Robert
Horn hook couplers may or may not work better. They certainly won't back as well (pushing). But aside from pushing, they tend to stay coupled quite well when properly adjusted. On most cars, the horn hooks were not properly adjusted, and tended to sag. The uncoupling pin would get caught in turnouts, causing derailments. The height mismatches caused occasional over- and under-runs. The built-in shelf would prevent the over- and under-running to the same extent of the knuckle couplers. But at the same time, the downward pressure on the shelf of a sagging partner could and did lead to derailments.
Which brings me to the question - what is causing knuckle couplers not to work for you? Is the swing too limited for your turns? Or are you experiencing over- and under-running due to sag? Are you using Kadee clones instead of Kadee couplers, where the knuckle "spring" often gives up?
British coaches are generally designed to run on less than 18" radius curves. American coaches are not, and many require more than 18". So more specifics would help us to help you. For 15" radius curves, you need to use "shorty" American coaches (scale 60ft or less). You may or may not need truck mounted couplers, but you will need long shank knuckle couplers. And a way to keep them from sagging.
my thoughts
Fred W
The other option is to resort to truck-mounting the couplers. This is where backing up will suffer, as the forces will try to skew the trucks causing the wheels to pick at the slightest irregularity. This is usually the problem with horn-hook couplers as well, as usually they were truck mounted. Horn hooks have an even stronger spring pushing them to the side, so this makes the condition even worse
--Randy
Thanks for this feedback. I'll continue to work away at this!
Some or most of the couplers are Kadees but a few are generic ones that came with these Athearn coaches. I think I was advised once (a few years ago, on this forum even!) to go with #219 Kadees. The 219 Kadees are taller, i.e. the knuckle part is higher and these are generally used for modern tank cars. It might not be 100% prototypical to use them on other coaches and freight cars, but this should reduce uncoupling, especially if some of the couplers are at slightly different heights and if there are some uneven areas of track. At least this is the advice that I vaguely recall from a few years ago!
So one of my solutions will be to replace the generic ones with Kadees.
If this is correct, I might try to use the 219's more often then.
Often, the coaches will work fine when placed in a different order. It seems that certain couplers "don't like" other couplers and I'm trying to patiently trouble shoot this.
I also have hook/horn couplers on several other coaches and they work fine -- they stay nicely coupled on the tight curves, hence my reasons for reverting back to those.
Thanks again for your feedback ... I"ll try to patiently continue to experiment with this!
Rob
a shelf coupler might be the ticket. <!-- m --><a class="postlink" href="http://kadee.com/htmbord/page119.htm">http://kadee.com/htmbord/page119.htm</a><!-- m --> I suspect it is an up and down motion that is the problem.
Lester Perry Wrote:a shelf coupler might be the ticket. <!-- m --><a class="postlink" href="http://kadee.com/htmbord/page119.htm">http://kadee.com/htmbord/page119.htm</a><!-- m --> I suspect it is an up and down motion that is the problem.
OK, it's coming back even more now! That's exactly what Gauge members recommended to me a few years ago -- shelf couplers. As far as I can remember, #218 or 219 Kadees were the shelf coupler kind, and these should work well to reduce uncoupling problems. They're prototypical for modern tank cars but you can get away using them elsewhere. I'll continue to try this.
Thanks again, Rob
The other thing you can do if the tight radius is causing problems is to make a "tongue" to mount your Kadees onto. You make it long enough to position the Kadees at the normal position, but the other end of the tongue mounts to the same screw as your trucks. The kadee will act like a talgo (truck mounted) coupler when going around tight radius curves, but it won't put the side force that leads to derailments when trying to back up the way truck mounted couplers do.
Rob: at 15" radius, you might have to go for a longer Kadee. They make variants that fit the #5 boxes but are longer.
Also check the heights against the Kadee gauge.
Look for couplers that are not mounted level -- they change height as they are pulled out.
Do you have any abrupt grade changes? Long cars can unhook on these.
BR60103 Wrote:Rob: at 15" radius, you might have to go for a longer Kadee. They make variants that fit the #5 boxes but are longer.
Also check the heights against the Kadee gauge.
Look for couplers that are not mounted level -- they change height as they are pulled out.
Do you have any abrupt grade changes? Long cars can unhook on these.
Thanks, David. I do have 1-2 longer Kadees. The LHS I used recommended these for locomotives. I did attach one of these to one of my coaches and it worked well for awhile, but now I think that is one of the couplers that is acting up!?
I still think this is part of the solution, as are the shelf couplers.
The layout is fairly flat -- I tried to work hard to make it this way. Still, there are some gradients at 1 or 2 of the turnouts where the track bulges up -- one of these is also just before some curves, so there is a combined problem (i.e. lifting up & down then swinging through a curve).
I'll keep plugging away at this !
Rob
RobertInOntario Wrote:I have a small 3.5x5.5 layout, which I usually use for operating my British trains but occasionally I like to run my North American HO stock on it. It seems that my (generally smaller) British trains can cope with its 15"R curves better than my North American ones. The knuckle couplers on many of my coaches don't like these tight curves & often uncouple. Just wondering if I should switch back to the more reliable hook & horn couplers, even though they're less realistic? I'm tired of experimenting with different kinds of Kadees to find ones that work.
Thanks,
Rob
It sounds more like a height problem than a radius problem (if it were radius, your cars would be pulling the others off the rails). Check the heights of your knuckles, and at the very least make them a standard height. they sell washer-shims to level them out. You almost have to buy the red and gray washers, simply because no two pieces are the same height, let alone standard height. they're cheap and a one time purchase ( i have a HUGE fleet of passenger equipment that i've shimmed and i still have plenty more years later).
Shelf couplers would definitely work, i use them in a lot of my Push-pull trains and that has removed almost all coupling problems (except for the occasional spring that frees itself, though this happens with all knuckle couplers so equipped). shelf couplers may also be prototypical for your coaches.
However, shelf couplers are expensive compared to Kadee #5s, and in truth, they more mask the problem rather than fix it. Ultimately, either your track is bad or your couplers are sagging, and both of those issues should be checked.