Large Scale Central

Coupler Replacement Advise Needed

I am looking to to replace the couplers on all of my Bachmann cars with Body mounts and would like advise on which ones to get. the min radius I will have to negotiate is 2 1/2 foot and I also want to be able to use a servo controlled coupler on the tender to couple and un-couple the cars. I do not want to use the new Kadee electronic couplers.

Would the Kadee #831’s be good for what what I want to do? I also have a few Delton cars I want to put body mount couplers on as well.

Any advise is welcome.

Dan S.

If you want to use the 831 gearbox, I would go with a 789 Center set knuckle. 831’s are too high on the car with their large offset. (IMO)

http://www.kadee.com/htmbord/page789-1789.htm

For the Delton cars, the job is pretty simple. I use Accucraft couplers, but they are mounted in Kaydee draft gear so my method would work for Kaydee couplers as well. See the entire write up here: http://www.largescalecentral.com/forums/topic/17251/thinking-about-body-mounted-coup

Bachman cars might be similar. Here is a teaser pic…

Thanks for the information, I like the look of the Accucraft couplers as well and the fact they have the little hole on the top that I can hook a servo actuator to to remotely uncouple the cars from the tender. The Kadee’s can’t do that without using their electronic one. Plus they are less expensive. I was looking at this one to use. http://accucraftestore.com/index.php?productID=831 But might get these instead: http://accucraftestore.com/index.php?productID=787

Dan

I would recommend:

not doing it, if you minimum radius is 2.5 feet.

I don’t see “good” operation until the radius is over 4 foot, preferably 5.

Have you experimented with body mount couplers on your curves?

Outfit a couple and try it. I don’t think it will work well.

Greg

Dan Stuettgen said:

Thanks for the information, I like the look of the Accucraft couplers as well and the fact they have the little hole on the top that I can hook a servo actuator to to remotely uncouple the cars from the tender. The Kadee’s can’t do that without using their electronic one. Plus they are less expensive. I was looking at this one to use. http://accucraftestore.com/index.php?productID=831 But might get these instead: http://accucraftestore.com/index.php?productID=787

Dan

The links you posted are for two different scales and two different mount types. The first being 1:20 designed to mount to a flat car end surface. The second being 1:29 designed to mount under a car.

My photos are the Accucraft 1:20 coupler head mounted in a Kaydee draft gear box. The 1:29 heads are different and would not mount that way.

Greg Elmassian said:

I would recommend:

not doing it, if you minimum radius is 2.5 feet.

I don’t see “good” operation until the radius is over 4 foot, preferably 5.

Have you experimented with body mount couplers on your curves?

Outfit a couple and try it. I don’t think it will work well.

Greg

Dan, I was going to comment on this too, but not having track down I felt perhaps I wasn’t qualified. Greg is correct to be concerned that on a radius that tight the the ends of the cars past the truck bolster will swing out far enough to bind body mounted couplers. Was to offset this are to use couplers with longer shanks and lots of side to side movement. Also shorter length cars will be less problematic Longer much worse. And of course but may not be an option use wider radius track. Pick your longest cars mount a pair of couplers and do some experimenting.

Dan, if you go back and research this topic on this site and MLS you will find the general consensus is that 10 foot diameter (5 foot radius) is the common “dividing line” between body mount and truck mount for average length cars, not even long ones.

If you are changing to body mount for appearance (which I fully understand), I’m sure you will have to go to either radically extended length shanks and/or draft gear that allows much greater side to side, as Randy said above.

But those methods will also not look very good, and you might be shooting yourself in the foot so to speak, increased car to car spacing with a “giraffes neck” on the couplers, or draft gear boxes with the sides cut away, and also most likely a wide notch at the end of the car.

If you run 20’ cars you might make it, but I think it’s dicey too.

Regards, Greg

With 2.5’ radius, I’d stick with the truck-mounted Kadees on your rolling stock. As others have stated, that’s too tight for body-mount couplers to work reliably unless your rolling stock is all on the very short side. I would agree that 4’ radius is the absolute minimum you’d want for reliable operation with body-mounted couplers, and that’s pushing it if you’re running equipment longer than “typical” LGB-length freight cars. “S” curves going into and out of sidings will hang you up. Even at 5’ radius, my 1:20 passenger cars won’t go through an “S” curve going into a siding. (Which is why I use #6 switches.) There’s nothing wrong with the truck-mounted Kadees. They work very reliably. You’ll want to make sure your trains aren’t overly-long, as the weight of the train puts strains on the trucks that may lead to derailments or unwanted uncoupling, but at 2.5’ radius, I get the sense your trains aren’t that long to where that’d be an issue.

You can still do the remote uncoupling with truck-mounted Kadees on your rolling stock. There are a couple ways to go about it. You might find that you can get away with a body-mounted uncoupler on the tender and truck-mounted couplers on the rolling stock. The tender is likely to be fairly short, so the offset from center when entering your curves is likely to be fairly reasonable–within the side-to-side play tolerances of the couplers. You’re not going to have much luck uncoupling on curves, but that’s usually an issue regardless. Alternatively, you can truck-mount the coupler on the tender and control it remotely. You’ll want to mount the servo on the bolster of the truck, so it’s always in the same alignment with the coupler. That shouldn’t be at all difficult to do.

Later,

K

I think Greg has it just about right for track radius. On my Fn3 stock I run all body mount Accucraft couplers. Most areas of my track they perform fine. I have one “S” curve created by two opposing Wide Radius (10ft Dia) switches that will occasionally cause wheels to lift from the track. This is a yard lead and I always run very slow. Most times the car will land back on the rails properly; but it looks pretty awful. I also have one spot indoors where the curvature is a bit tight that will occasionally cause a derailment due to the body mounts. For the most part my railroad performs well with body mounts but most all of my curves are very broad.

The short Bachmann Fn3 2-Bay hoppers will even go through an R1 switch coupled to a very short engine (Porter).

I agree with the advise to do some testing before committing to a major change. Not sure how I missed that you have some 2.5’ radius track. That will likely be a big problem with body mounts.

Thanks guys for all of the input, Looks Like I have to go back a re-evaluate what I want to do. I have yet to put track down and had planned on Starting in January, and I had planned on using 10 foot diameter and 8 foot diameter curves throughout the railway and home made #5 and #6 turnouts as all the track will be hand laid on Ceder Ties.

Maybe I will just have to figure out what accucraft coupler will work on the tender that will couple to the existing bachmann ones and still be able to remotely uncouple the tender from the cars.

I will have to do some experiments with one of my Bachmann tenders as she what I can work out. I will keep you posted.

Dan

Colorado and Rio Grande Southern

http://danshobbies.webstarts.com/index.html

Thanks guys for all of the input, Looks Like I have to go back a re-evaluate what I want to do. I have yet to put track down and had planned on Starting in January, and I had planned on using 10 foot diameter and 8 foot diameter curves throughout the railway and home made #5 and #6 turnouts as all the track will be hand laid on Ceder Ties.

Maybe I will just have to figure out what accucraft coupler will work on the tender that will couple to the existing bachmann ones and still be able to remotely uncouple the tender from the cars.

I will have to do some experiments with one of my Bachmann tenders as she what I can work out. I will keep you posted.

Dan

Colorado and Rio Grande Southern

http://danshobbies.webstarts.com/index.html

Thanks guys for all of the input, Looks Like I have to go back a re-evaluate what I want to do. I have yet to put track down and had planned on Starting in January, and I had planned on using 10 foot diameter and 8 foot diameter curves throughout the railway and home made #5 and #6 turnouts as all the track will be hand laid on Ceder Ties.

Maybe I will just have to figure out what accucraft coupler will work on the tender that will couple to the existing bachmann ones and still be able to remotely uncouple the tender from the cars.

I will have to do some experiments with one of my Bachmann tenders as she what I can work out. I will keep you posted.

Dan

Colorado and Rio Grande Southern

http://danshobbies.webstarts.com/index.html

Sorry about the triple post guys, The cat stepped on the enter key.

Dan

So where did 2.5 Ft Radius come from? You should be fine with 8 and 10 foot diameter curves.

Dan Stuettgen said:

Sorry about the triple post guys, The cat stepped on the enter key.

Dan

That’s halairiuos.

Dan in you first post you said your curves were “down to 2.5 ’ radius” or 5 foot diameter. In you last post you speak of 10 or 8 foot diameter. This would be or be much more workable than 5 foot Diameter. Is this your new plan or did something get mis-typed? If your going to run 10 and 8 foot Diameter I would stay on your plan for body mounts.

And don’t test with the short tender, test with your longest cars.

The 2.5 foot radius was because I might have a couple sidings where I will be using tighter curves. But for the Yard and mainline, it will be 8ft and 10ft diameter curves as I am hand laying all of it using a track system I am developing, so I can hand lay the track on Sintra bases and then install them after the track is done. Take a look at my website and look at the turnouts photos under projects and you will see what I mean.

Dan

Colorado and Rio Grande Southern

http://danshobbies.webstarts.com/index.html