Hey guys…which is better for tighter curves? body mounted or truck mounted couplers?
Thanks, Ken
Supposedly, truck mounted couplers, but I replace all truck mounted couplers with body mounted couplers for better reliability especially when backing up.
Depends on many factors. In general for short trains on really tight curves a truck mounted coupler always aligns with the track so they couple and uncouple better. Plus there is no lateral stress on the coupler or car body entering, exiting a curve. Doubly true on an s-curve.
On the other hand with truck mounted couplers there is lateral stress on the wheel sets going around a curve. The stress directly on the truck makes them want to go straight. This means the longer/heavier the train the more sideways stress there is on the actual wheels grinding them into the side of the track.
For body mounted couplers there is more sideways swing of the coupler (away from the centerline of the track) on curves. Putting a short car right next to a long car can cause derailments. The tighter the curve, the longer the car, and the further inset the bolster the more pronounced this effect. On an S-curve the sideways swing is in opposite directions causing real problems.
Very few prototype cars have truck mounted couplers.
I would never think of using truck mounted couplers on my HO equipment (larger curves, longer trains, looks goofy). I would never think of using anything but truck mounted couplers on the G-gauge stuff (tight curves, short trains)
The only time there ever is a choice in my o/p is on passenger cars for the sheer length issues.For me personally every piece of rolling stock be it a passenger car or any type of freight cat etc. has body mounted couplers. In my O/P truck mounted couplers are strictly train set quality and have ZERO realism. If you run them you might as well still use horn hook couplers.
Tight curves you mean like 15 or 18 inch curves? If so it doesn’t matter since 40-50’ cars will work on these curves with body mounted couplers.
Avoid truck mounted couplers as they will only cause you grief.
Kenny, are you having derailment problems in turns?
When I got started I like pulling long trains and had tight turns and nothing but problems. Before I changed over to all body mounted Kadee’s I did a few other things that helped me a lot.
1 Got the car’s up to NMRA weight standards. If you don’t know the rule it is as follows. If your car is 7 inches long take 7 X .5 + 1 = 4.5 oz that is what your car should weight in at. If 5 inches 5 X .5 + 1 = 3.5 oz. same math regardless of how long the car is.
2 Get a Truck Tuning tool, Micro Mark’s sell them. It is used to clean up the area where the axles mount in the trucks. If you don’t know what it is, look in the posting that is listed as OMG it happen again. You may be shocked how much easier your rolling stock can roll. Easier they roll less side forces you will have in a tight turn and the longer train you can run.
3 If you have any rolling stock with plastic axles, replaces with metal axles. Plastic axles will warp, ask me how I know? I was using Walther’s Metal Axles with Plastic Wheels when I started correcting my rolling stock.
With out changing the couplers or there mounting points I was able to get up to 40 cars going around 18" turns.
I now have all body mounted Kadee’s and have not looked back. I can lash up my shortlist car to my longest and have no problems. My turns are bigger now I will add.
Cuda Ken
As others have said, there are a range of factors to consider. I have a lot of 18-inch curves on my layout. But, I model the Transition Era, so I don’t run today’s long engines, well cars, or any freight cars longer than 50 feet. Mostly, my rolling stock is 40 feet or less, and nothing in that range should have a problem with curves using well-mounted body-mount couplers.
I do, however, have two sets of passenger cars. I’ve got an ancient set of Mantua streamlined metal cars, actually made of aluminum. These are about 75-foot cars, and they have truck-mounted couplers. They wouldn’t make it around the curves with body-mounts, so I live with the slight lack of realism. The other passenger train consist is Rivarossi coaches. They aren’t quite as long, and they have special body-mount couplers with a swing mount, which allow not only the coupler to move side to side, but the entire draft gear, giving a wider range of movement.
A lot of my rolling stock has been with me for a half-century or more. I had a lot of freight cars with truck-mounted horn hooks, and I’ve converted them all to body-mount Kadees. They look and perform much better now.
one thing not brought up is the problems with backing up a train with truck mounted couplers. On truck mounted couplers the backward force will cause the trucks to pivot and can cause derailments , specially on a longer train.
Most of my freight cars have both - but the ‘trucks’ are of the type the Reverend Awdrey referred to as, “Troublesome,” four wheel cars of (maximum) 18 ton capacity.
More accurately, all of my couplers are body mounted. On radii down to 550mm (<22 inch) I can handle 20 meter cars, which are just about equivalent to U.S. prototype 60 footers in geometry. The really tight curves, 350mm (<14 inch) radius, are restricted to shorter cars (with one exception) and teakettle tank locos (again, with one exception.) The exceptions are a heavy machinery flat - but it has four trucks and span bolsters, so the couplers are mounted on the equivalent of short flat cars - and a cosmetically modified Mantua Uintah (wide gauge) 2-6-6-2T. The articulated will take a 12 inch radius, but that’s what its prototype was designed for.
The major objection to truck-mounted couplers (ordinary-size trucks, 2 or more per car) is that the interaction between couplers can (and, when backing up, will) force the flanges against the railheads. They will find every irregularity - and let you know exactly where it is! Unless you lay and maintain your track to Shinkansen standards, body-mounts are much more forgiving.
Chuck (Modeling Central Japan in September, 964 - in 1:80 scale, aka HOj)