Does the Metal Kadee Centering Spring have to go above the coupler?

Model Railroader General Discussion (Model Railroader)
1

I just realized that in all the kit instructions, the metal spring goes in above the coupler. Does this effect the operation, or could I reverse it?

2

I have done so, when I didn’t know any better. It works fine. Glueing the coupler box does not work, when that spring eventually wears out. DAMHIK [:S]

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Hi Harrison,

If you look at the spring you will see that the two sides are different. My understanding is that the spring is designed to allow the coupler to move more easily in one direction to facilitate uncoupling. As was said, the spring does seem to work when reversed but I would question why you would do that when Kadee has specified that the spring should only be installed on top of the coupler. I know it may make the couplers easier to assemble, but if you are having trouble putting them together Kadee has a jig that holds the coupler while you assemble it.

https://www.kadee.com/index.php?main_page=product_info&products_id=424

The easier solution is to buy Kadee #148 couplers. They have the centering spring built right in. They are much easier to work with. I don’t use the #5s anymore, just #148s. There are versions with underset and overset shanks if you need them.

https://www.kadee.com/advanced_search_result.htm?main_page=advanced_search_result&search_in_description=0&keyword=%23148

Dave

4

Dave, Before I converted to KDs in 66/67 we had a highly respected local “Master Modeler”( not NMRA type) come to the Columbus HO club to teach us how to “correctly” install KD #5s.

I never notice all of my centering springs was installed upside down until 1977 when my wife made a observation while watching me assemble BB car kits…

She ask me in innocent voice: “Honey, why are you putting that brass thingy in upside down?”

I foolessly stated it wasn’t upside down…

Some where modelers was happy and cheerful but,there was no joy at my work bench that day[sigh] -----she showed me the instructions.[D)][B)][:$]

5

I installed them all upside down for years, until I found out I was doing it wrong.

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They all worked just fine with the spring installed incorrectly. I would not sweat it if you have some that are wrong.

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-Kevin

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[(-D][(-D][(-D][(-D]

Basic survival rule for a long life: listen to your wife![swg][(-D][(-D][(-D]

Dave

7

I was not aware of the design feature of the large brass spring. I, too, have gone to the easier to install #148 for most installations.

But it raises an interesting technical point. If the original (separate) centering device was designed weaker on the uncoupling side, did Kadee design this behavior into the #148, which has a whisker on each side?

EDIT: A different angle on the whisker edge on each side would accomplish that but not center the spring. What might work would be a slightly weaker whisker on the uncoupling side. That would require that the springs each just barely touch the sides of the coupler box when centered, so that the stronger spring did not push the couple off center. I suspect that sophistication was not included. The springs on each side seem the same, 0.12mm diameter and appear the same length. And the effective length is the same, as each spring touches its side of the box, the same distance from the pivot point.

Just a matter of interest.

8

I noticed a bit back that there is a right and wrong way to put a #5 in, but I don’t think it would seriously effect operations if the springs were in wrong.

I don’t think I have actually ever put the springs in on the wrong side, but I have on numerous occasions put the entire coupler upside down so the trip pin was pointing up! I can confirm they will not work properly if you put them in that way!

9

My understanding is the KD bronze spring is designed to allow the delayed coupling action (if you use that feature). If it isn’t installed per KD instructions, that feature may not work properly.

Here is a link to the instructions:

https://www.kadee.com/instruc

If you click on the HO No. 5 instuctions, a PDF opens which include diagrams which show the bronze spring above the coupler in the box.

In some cases I have installed the spring under the coupler to give it a bit more height and the coupler worked fine, although the delay action may not work as well as it is supposed to.

10

Thanks for the feedback everyone.

I have done that to. [banghead]

11

yes, the spring goes above … this is because the brass wears quicker than the plastic will, and adversely affect the operation over time …

however, unless you operate a great deal, you can safely put the spring underneath … it does fit there as well …

12

Hi Isaac,

Been there, done that! Why does it always happen with the coupler that was giving you the most difficulty in the first place?!?[(-D][(-D][D)][(-D]

Dave

13

I try to put the springs on top, but there have been some cases where it fit better below the coupler (like on some of my Athearn BB kits where the center pin faces up instead of down). I don’t use the extra features of the couplers, so for me, it’s never caused a problem.

14

Or it happens in front of other people. First club show I was at (and not the first club I was a member of, and FAR from my first time using Kadee couplers), someone backed in to a cut of Athearn hoppers too had and popped a coupler. I was standign right there so I gradded it to fix it, but I was also talking to a spectator, along with another club member who had been there significantly longer than me. And promptly put the coupler in upside-down. Doh! How come when I’m sitting by myself at my workbench, assembling kits, i NEVER put one in upside down?

–Randy

15

I never gave it much thought as to which is the right way. Almost always I am installing the couplers with the car turned upside down so naturally the first thing I do is put the brass centering spring in first which puts it on the top. I guess if you are using the KD coupler pockets and installing them on the car you could do it either way but I can’t remember the last time I did that.

I’m glad to know I’m not the only one who occasionally puts the coupler on upside down with the pin pointing up.

16

One great feature of most Kadee coupler boxes is that the cover is thinner than the box.

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If you assemble the whole thing upside down in the box, you can use this feature to correct some slight coupler height issues.

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This is mentioned in the 30 series intruction, but it works with other coupler boxes as well.

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-Kevin

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17

That’s because there is nobody there to be embarrased in front of! Why would Murphy waste his time when he can’t embarrass you?!?[swg][(-D][(-D][(-D]

Dave

18

Harrison, the box spring is designed to “only” to be installed “on top of the coupler”. If you look closely at at the spring you will see a big difference in the spring arms. As mentioned, there’s a strong and weak side to help with uncoupling and delayed action. Also, note the end of the shank on the #5 type of couplers have different angles that are not symmetrical and these match the different spring arm angles. This is why it’s important to always have the spring on top. If the spring is installed on the bottom it may work OK but eventually there will be problems. Note that when the couplers are coupled and in operation this takes the centering spring out of the performance issue so the spring on the bottom has no affect. It’s when the coupler has to be uncoupled and centered properley that problems will arise and the spring may wear out faster. Remember that this is all late 1950s technology which is still the most popular in our coupler line, presently even more than our whisker couplers.

Sam Clarke R&D Kadee Quality Products

19

Thanks for the offical verdict Sam!

20

I am so happy that someone from Kadee takes the time to respond and clear things up.

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Thank you Sam.

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-Kevin

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