# Swapping Bachmann 1:22.5 couplers out for USA 1:29 couplers



## catherine yronwode (Oct 9, 2013)

Okay, i have a question for the experienced ones. 

1) I like the look of knuckle couples. 

2) I run three consists of Bachmann Big Haulers (freight, passenger, and circus) at 1:22.5. 

3) In my opinion, Bachmann 1:22.5 knuckle couplers are out of scale with their own trains (too big in appearance) and they decouple spontaneously at all the wrong times. 

4) I run one consist of USAT billboard reefers at 1:29 behind a Bachmann Annie.

5) In my opinion, USAT 1:29 knuckle couplers look great and they stay coupled. 

6) I want to swap out all my Bachmann 1:22.5 knuckle couples for new USAT 1:29 knuckle couplers. 

7) Do i need to hire someone to do the job or can i do it myself -- and if i can do it myself, what tools do i need to do to accomplish this, and how do i do it?

Please reply in simple step-by-step terms. Please take it for granted that i know nothing about couplers or the varied ways they can be mounted. 

Thanks for any opinions or helpful suggestions. 

cat


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## Dan Pierce (Jan 2, 2008)

For rolling stock, all that is neeeded is a screwdriver to remove the Bachman coupler and then install the USA.
The freight cars I have one can interchange the following couplers on LGB, USA, Bachmann with either Knuckles or hook and loops as the mounts are identical.

Hartland and Aristo use a different mounting procedure.

Also, Kadee are made for most large scale rolling stock and for many engines.

While you can mount the knuckles on the truck, they are much better when body mounted.

Why is this?? when running down the track, the trucks flex vertically and knuckles uncouple as one rises when the other lowers, so switching them out may not solve your problems unless you go to body mounting. And the longer the train the more often this occurs.

At open houses I always suggest that double hook and loops will minimize failures and keep trains short for problem free operation.


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## catherine yronwode (Oct 9, 2013)

Thank you. That was exactly what i wanted to know. 

About the Bachmanns uncoupling problem -- i think maybe they are old, worn couplers. I got some used rolling stock off of ebay, and those cars, and ONLY those, from that one purchase, have weak, weird coupling. The little pin-thing (i don't know its technical name) slips and the couplers uncouple. This is only on my Jackson Sharp coaches. All the other Bachmann cars have a positive "click" when you move the pin-thing and they stay coupled. I still don't like the way they look, but at least they stay together. 

So, next question:

How does one "go to body mounting"?

Is there an illustrated article describing this?


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## Pete Thornton (Jan 2, 2008)

catherine yronwode said:


> Thank you. That was exactly what i wanted to know.
> 
> About the Bachmanns uncoupling problem -- i think maybe they are old, worn couplers. I got some used rolling stock off of ebay, and those cars, and ONLY those, from that one purchase, have weak, weird coupling. The little pin-thing (i don't know its technical name) slips and the couplers uncouple. This is only on my Jackson Sharp coaches. All the other Bachmann cars have a positive "click" when you move the pin-thing and they stay coupled. I still don't like the way they look, but at least they stay together.
> 
> ...


Catherine,

I found that any small object on the track, like a dried leaf, would trip the coupler lift pin [that's what it is called.] Bachmann couplers hang down very low!

One solution to old, weak couplers is to paint them! Don't know exactly why, but it's been claimed for years that spraying them with black paint will stop them wanting to uncouple. Guess it makes them stiffer or something. I think it works - but I replaced my Bachmann couplers with USAT years ago - for the same reasons that you want to.

Re: body mounting. 
I'm sure there is a thread somewhere around here that includes body mounting the couplers - but it is probably hidden in a "how-to" about something else, like making a flat car.

First thing you have to do is make a coupler height gauge - a piece of wood with a coupler screwed to it and slots for the rail underneath. Sit it on the track and then you can tell exactly how high each coupler needs to be. (Obviously, you make it the height you want to be your standard - probably the height of the 1/29th couplers on the USAT frieghts - or maybe check around for the exact scale height.)

USAT couplers have a long springy tang behnd the mounting hole that keeps the coupler centered. You need a long "U" shaped channel the right width that you can cut to a fixed size to hold the coupler. I'm not sure what I used but I will look around for some photos.


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## s-4 (Jan 2, 2008)

Cat,
I would step up to Kadees if you're going to go body-mounted. They have track mounted height gauges to help you convert your cars. Its usually a matter of drilling a few screw holes on the underframe of the car and then adding shims (wood, plastic, whatever you have) to bring it to the right height. Be aware though, body mount coupling height is much higher than the factory coupling height....so you will have to change everything! 

Its both an aesthetic and performance improving upgrade, but its a comittment for sure! 

I have body mounted couplers on all of my 1:20.3 equipment and its great! I would do it to my 1/29 scale equipment in a heartbeat, but the diesel locomotives are going to require a lot of work to allow straight-shank couplers. This is because the diesels have body mount couplers already, but they are molded too low. Still, despite the work, its a worth while thing to consider.


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## Pete Thornton (Jan 2, 2008)

I wouldn't argue with S-4 that it is quite a commitment. Personally I am not a fan of Kadees - the USAT couplers were less expensive, more prototypical, and easier to fit.

I found a couple of photos in my 'how-to make a 2-bay hopper from a 3-bay" (in 2007.)




















What you see there is a piece of rectangular brass tube, 1/8" x 3/8" (I think) with a hole drilled through it for a bolt that holds the coupler. The bolt also passes through the body of the car. On this hopper, I used extra length and cut off 3 sides to make a flat tang with a hole that fits over the truck mount.

A Dremel cut-off was used for most of this. I also cut a 1/16" slot at each corner of the end and bent the 1/8" side brass outwards to let the coupler swing a little more.


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## Homo Habilis (Jul 29, 2011)

You may want to Google "site:mylargescale.com body mount coupler" for a number of threads discussing various conversions.

Also, whether using Kadees or not, you could review their various > methods < for their couplers and adapt them to you own needs.


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## catherine yronwode (Oct 9, 2013)

Thanks, all -- i will not be choosing Kadees, as i do like the look of the USAT coulpers better. 

After looking at all the talk of body mounted couplers, i think that is beyond my skill level. I think that i got the answer i needed -- one CAN swap USAT couplers for Bachmann couplers with no modifications. That makes me happy.

Also, thanks for the term "coupler lift pin" -- so much more technical-sounding than "that little pin-thing on the coupler" -- and, yes, the problem with the affected cars is that tiny items between the rails that do not interfere with power (e.g. leaves) will cause that lift-pin to lift ... and bye-bye train. To be fair, NOT ALL of my Bachmann couplers do that, but the USAT couplers NEVER do it, running on the same track under the same conditions. 

I may try the painting trick in the meantime. Thanks for sharing that.

You folks are very kind for helping me. Thanks!


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## Greg Elmassian (Jan 3, 2008)

Wow!

Dan says body mounts are better - BUT if you have tighter curves they won't work, so we should establish the curve diameters/radii FIRST.

Pete: WOW! no side to side movement in that mount? What do you have 20' diameter curves?

Greg


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## catherine yronwode (Oct 9, 2013)

This is the tightest curve on my layout, a half-circle loop at one end of the dogbone:


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