I received an email from Kadee advertising some new self centering trucks. The very small photo shows a truck bolster with a hole, and a screw through the hole – looks like pretty standard stuff to me. Their website does not give much information but does indicate it is patented technology.
Can someone explain what exactly is different about a Kadee self centering truck?
Dave Nelson
yes, by all means, please explain. i looked at their web site and realize now why my life has been so unfulfilled for the last 63 years. i must have had operational problems that went un-noticed all this time.
grizlump
Yes, I can. Or rather, the patent can. The patent number they show on their website is 7 434 518. You can find that patent here: http://www.freepatentsonline.com/7434518.html.
If you scroll down toward the bottom you’ll see something that says “download pdf 7434518”. That has all the sketches showing the new construction.
Regards
they’ve actually had self-centering trucks for several years now. Basically, there’s an insert that goes through the truck from the bottom and attaches to the frame. Two small “pins”, one on each side of the post, fit into V-shaped grooves on the truck bolster. When you pick the car up, if that center post is aligned properly, those grooves will ensure that the truck centers itself.
It’s sort of an interesting idea, but part of me says “Why? Most of us are capable of centering the trucks manually.”
The recently released Kadee cars come with them factory installed.
I thought the whole point of the self-centering trucks was that they perform better on the layout.
On my layout, they seem to have less side to side rocking motion after passing over an uneven joint than other cars. They just center much faster than other rolling stock. I have 3 of the new Atlas steam era boxcars, and one of them just rocks a lot more than the others. All of them seem to rock more than recent Kadee cars.
John
I would think that, between tire profile and flanges, there wouldn’t be much call for self-centering trucks in the HO world.
-Crandell
You THINK you don’t need that, especially when you can take any old car and get it accurately on the rails in one try, every time. But then pick up a Kadee car with the self-centering trucks - it really is easier! You’d think self-centering would be an issue with curves and turnouts, but check out the Kadee design, when the weight of the car is on the trucks, the self-centering function is disengaged and doesn’t interfere with the free swiveling of the trucks. Quite clever, actually.
–Randy
All I want is for the trucks/wheels to stay on the rails.
Mark
That, thankfully, I don’t have much problem with. And I use that ‘junky’ Atlas track. Go figure.
–Randy
I’m not sure the self-centering feature makes much difference in freight trucks - there isn’t quite the wallow I often see with steam engines. But I think the technology could prove quite useful in helping a pilot truck guide a steam locomotive the same way the prototype pilot truck does.
I also see some benefit in helping reduce car body wobble, similar to the way some other multi-point truck mountings do.
Is the average modeler going to notice the difference? If you can’t see or enjoy the difference between sprung and rigid trucks, the even more subtle differences with self-centering trucks aren’t going to matter. But as one goes to finer scale wheels and track standards, rigid truck frames and single point truck mounts don’t cut it the way they did with the coarser standards. P87 wheels and track pretty much require some equalization for successful ops.
just my thoughts and experiences
Fred W
Can’t argue with that!
Actually, the primary purpose seems to be to get the truck on the rails when the car is being lowered into place by the Great Hand of God (aka 0-5-0 skyhook.) If your car is on the rails and your trackwork is bulletproof, this thing is about as necessary as an air bag.
And now, what happens when the layout has about 77% of its trackage on curves of various radii? Seems to me that the gadget would be more nuisance than help…
Oh, well. Most of my freight cars only have four wheels, so centering their truck is moot.
Chuck (Modeling Central Japan in September, 1964)
Guys, as Randy and Mark have indicated, the “self-centering” feature on Kadee trucks is NOT in play when the car is on the rails. There is no difference in operation between the two types, even on curves. The only time the feature is functional is when the car is being placed on the rails via the Giant 5-Fingered Airlift, and then it just aligns the truck with the longitudinal axis of the car, to make it easier to re-rail it. I consider it to be interesting, but not worth paying the extra money for…
Unfortunately, (or perhaps fortunately!), our models are not heavy enough to make the method the prototype used to allow pilot trucks to guide locomotives practical. I have, however, seen model pilot trucks with centering springs (e.g.: the Varney Casey Jones4-6-0), and they actually do help guide the locomotive into curves. With the modern RP-25 flanges, however, one has to use a very light springing to make it work, and the locomotive will need some really serious weight.
Thank you. That is most helpful, particularly the drawings in the PDF – although back in my mind I seemed to recall some Japanese made freight cars from the late 1940s that I was given eons ago that had a similar two part construction centered around the hole in the bolster.
When you actually slog through the typical patent language (which always sounds like a Monty Python sketch to me – it helps to imagine John Cleese reading the patent) at least part of the novelty of the design which deserves the patent is the greater ease of construction at Kadee’s end of things by eliminating the tiny springs, while not lessening and perhaps even improving trackability. Not much is said in the patent about the wheels keeping parallel to the car when lifted.
On that front, years ago I had an inexpensive Hornby DoublO train set (actual OO scale tinplate) that my mother found for sale at a department store for $2.99 a set (0-6-0, two passenger cars, and a circle of bullhead rail). The passenger car trucks had a shaft that extended towards the center of the car, with lengths of neoprene tubing on the shafts, which functions as a very soft spring that kept the trucks parallel to the car when lifted.
Dave Nelson