Large Scale Central

Mounting Kadee couplers to USAT

Modeling Rolling stock
#1

I once standardized my fleet to the old Bachmann low coupler height for quick and easy conversations.But now I’m in the process of slowly converting to Kadee #1 and/or Burl’s couplers. I had always assumed that the mounting pads on the USAT cars was for the #1 coupler, not the G size as I found out tonight.

Other than drilling new holes for mounting the #1 box is there any other methods? I looked at Ted D’s notes over on Greg’s site, but Ted uses the G size coupler and mounting box.

My other option is to just gut the Kadee mounting boxes and use a resin copy of Burl’s draft gear that I had 3D printed a while ago.

#2

Check out Greg’s site : https://elmassian.com/index.php?option=com_content&view=article&id=12&Itemid=813

Go to the main menu sidebar to the left!

#3

Sean,
Reread my first post. Greg’s site has good info but its all for the “G” size coupler installs, not the #1 scale ones.

Edit to say: USAT are designed for a 906 box, not a 907. I would prefer to use the narrower 907 box.

Most likely I just end up using a cast of Burl’s draft gear as it has a more prototypical draft gear box and opening.

#4

Sorry

#5

Not a problem. Just wondering if anyone else had come up with a solution.

#6

Are you referring to the large modern cars like the 53 foot tankers and 3 bay hoppers?

#7

Paul,
I looked at 40’ steel boxcar, and 50’ boxcar/reefer. They look to have the same pattern. BTW, the coupler in using is the #1906.

#8

Craig,

Come on down a little early Saturday and I will show you how I have been mounting my Kadee #1 couplers.

#9

Craig,

I have used a lot of the older 820/920, same as the 1906 for mounting. My favorite is the 1789/1907. By far the most used conversion on my locomotives and cars. Most freight cars including the USA boxcars only need a 1/16 shim with the 1789. There is one variable to consider on some cars. If you have added your own metal wheels it could change the coupler mounting height a little dependimg on the wheel diameter. Very important to use the Kadee gauge.

#10

Very important to use the Kadee gauge.

I second that.

Also I use a piece of 1/8th thick stripwood as a gauge, to make sure the trip pins are 1/8th inch above the railheads. Most times I find they are too low right out of the package.

#11

What’s the correct height? I know on the prototype it is 34 1/2" +/- 2" from the centerline of the couplers. I was planning on making 34 1/2" my standard as any interchange with regular equipment isn’t likely to happen if I got to Proto 29 track instead of 45mm. I will likely keep one locomotive, boxcar (extra battery) and a caboose set to 45mm gauge so those will need the correct height couplers.

#12

https://kadee.com/html/829-880ins.pdf

1 1/16 from railtop to coupler centerline for #1 scale

1 1/8 from railtop to coupler centerline for G scale

#13

34 1/2" in 1/29 is 1.189"
Kadee calls for a 1.203"

Diferrence of .014"

1/16" = .0625"

So it looks like if I use USAT mount without a 1/16" spacer plate, the carbody would need to be raised another 1/16" to get within a few thousands of a scale 34 1/2" height.

#14

Craig,

I would just use the Kadee gauge. That way your locos and cars will be standard and able to run with cars on many different layouts. I have friends who bring equipment over here to run and there is no problem because all is the same. Hope to see you Saturday.

#15

Oh but that’s the easy solution. :wink:

#16

Craig, spoken like a true basher/builder. But think about this; if you make this part easy, then you can spend the time saved on this part somwhere else, on something hard.

#17

David Maynard said:

https://kadee.com/html/829-880ins.pdf

1 1/16 from railtop to coupler centerline for #1 scale

1 1/8 from railtop to coupler centerline for G scale

That 1/16" makes a “yuge” difference!

#18

I’m confused… so, I think I’ll try to figure it out. (you guys check my math)

So the centerline of the #1 coupler should be 1-1/16 from the railhead, that’s 1-1/16" lower than using the stock G scale coupler on these cars, and following the guidelines.

We are talking the body mount Kadees, so we are talking the 906 in G scale: (I’m going to stick with the new style knuckles here)

Which is at the perfect height on the USAT car, and would be 1/16" too low to meet the #1 scale “standard” height.

Then we are going to use the 1906 #1 scale coupler:

So the question is how does the centerline of the 2 couplers in their draft gear housings vary?

So if you look at the instructions… ( https://kadee.com/html/S-G_body_mount_couplers_ins.pdf )

For G scale, (measured from rail head) the center of the coupler is 1-1/8" and the bottom of the mounting pad is 1-19/64, if you subtract this numbers you get the distance from the mounting pad to the centerline of the coupler, 1-19/64 minus 1-8/64 equals 11/64" for G scale

(Note a typo on the centerline for G, show wrong fraction but right decimal)

For #1 scale it’s 1-1/16" centerline and 1-13/64" coupler pad, so 1-13/64 minus 1-4/64 = 9/64"

To be clear, the distance from the centerline of the coupler to the outside of the coupler box is 1/32" less for the #1 coupler as compared to the G coupler.

so a number #1 coupler put on a “G” scale pad is 1/32" higher than a G scale coupler, but you want the center line 2/32" lower, so bottom line, a #1 scale coupler on the USAT car is 1/32" (0.03125") lower than desired… I could probably live with 3 hundredths of an inch off the desired height.

I would think that if other cars are at the 1-1/16" centerline this would not cause operational difficulties, and not look bad.

Greg

#19

That’s about it, Greg. This also gives the smaller #1 coupler more “wiggle room,” when coupled to the larger “G” Coupler, going over less than steller track. Like mine.

What happened to the emoticons, and the link button? Enquiring minds want to know.

#20

Funny you should mention the emoticons, I tried to find them and they are gone… Maybe Bob updated the WYSIWYG editor and it went back to a default configuration.

My site has a similar editor, and I can configure which buttons show in the editor.

Anyway, I shure would not lose sleep or worry about trying to mill 1/32" of an inch off the usat coupler pads.

Greg