Jim Kelly -"The case for body-mounted couplers"

[rogergperkins]

Putting coupler location on the list of "to-dos" for the next layout, assuming at age 73, we will be moved to a house where there is room for a layout. 

I stopped by the LHS yesterday afternoon and dropped $20+ USD for some body mountable couplers,  coupler-less trucks and the MTL tap and drill package.
I did one end of one MTL double door boxcar to test the concept.

1. I am not certain how many spacers I should have used to put the body mounted coupler at the proper level to align with the locomotive coupler; I used only one.
2. My first attempt with this car was not successful....thus emphasizing the multiplicity of factors that come to play on this issue of backing n-scale trains.

Happy Easter.

[jdcolombo]

Putting coupler location on the list of "to-dos" for the next layout, assuming at age 73, we will be moved to a house where there is room for a layout. 

I stopped by the LHS yesterday afternoon and dropped $20+ USD for some body mountable couplers,  coupler-less trucks and the MTL tap and drill package.
I did one end of one MTL double door boxcar to test the concept.

1. I am not certain how many spacers I should have used to put the body mounted coupler at the proper level to align with the locomotive coupler; I used only one.
2. My first attempt with this car was not successful....thus emphasizing the multiplicity of factors that come to play on this issue of backing n-scale trains.

Happy Easter.

Hi Roger.

Don't know what coupler you were using, but today many pieces of rolling stock have the underbody at the right height to mount a 1015 without any shims.  Different MT couplers have different coupler heights.  MT makes a coupler height gauge (a coupler mounted in a hefty piece of steel that sits between the rails) that I urge you to get (DO NOT waste your money on the "micrometer-style" height gauge; I've never been able to get this to work usefully).   Another possibility is simply to use an MT truck with a truck-mounted coupler as a "height gauge".

What I do is take a 1015, drill a hole in the underbody, and mount the coupler.  Then I check the height against the gauge.  Too high? use a small square of styrene as a shim.  I use .010, .015, and .020 X .250 strips for this purpose - cut a piece of strip to the length you need, and use some plastic cement (if the underbody is plastic) or CA to cement the shim to the underbody.  Drill through from the top of the underbody where your previous mounting hole is with your same drill and mount the coupler with the shim in place.

By the way, I never use a tap for plastic underbodies.  I use a "one-size smaller" drill bit than the tap drill, and let the mounting screw self-tap into the plastic.  You DO need to use the tap for metal underbodies.

Final suggestion: use a small piece of 400-grit sandpaper to "rough up" the top surface of the coupler box before mounting.  Otherwise, the delrin plastic of the coupler box is so slippery that it will move even when the mounting screw is tightened.  It might move even if you rough up the surface.  If it does, I put a TINY drop of medium-viscosity CA on the very back tip of the coupler box before mounting to hold it in place.

John C.

[rogergperkins]

I selected 1016-1-B(rown) because that is what the LHS had.  I used one shim on the MTL double door 40' boxcar mount.
I checked again today with the MTL gauge and it seems to align.
I note that the clearance between the wheel set axle and the mounting screw is very small.

[jdcolombo]

Hi again, Roger.

Most MT boxcars and other "enclosed" rolling stock (e.g., reefers and tank cars) are built to use a 1027 coupler, which is hard to find at an LHS (they're even somewhat hard to find mail order!  You can get them directly from the MT store, part number 001 02 014).  The 1027 has a lower coupler height than the 1015/1016.  It also has a little "pin" in the back of the top of the coupler box to keep the coupler from twisting.  If you look at the underside of a standard MT underbody, you will see a pad with two holes.  The front hole goes all the way through the underbody, and needs to be tapped.  The back hole is for the pin on the 1027 coupler box.  Here is a PDF about the 1027:

http://www.modelbaneteknik.dk/n-scale/kobl/mt1027-e.pdf

You can use a 1015/1016 (they are the same coupler, except that the 1016 has a longer shank for a wider swing), but as you've seen, you need to use one of the shims that come with the coupler.  With the shim, the 1016 should come out at exactly the right height.  The only downside is that the 1016 doesn't have the nifty little pin that keeps the coupler from twisting.   That's why I like to use 1027's on the MT rolling stock that is built for them.  On everything else, I use the 1015/1016 and a little CA if necessary to keep the coupler from twisting.

I've converted about 500 pieces of rolling stock since I started back in 1994.  Newer stuff is a LOT easier, because most manufacturers now build their underbodies to take a 1015/1016 without a shim, and many even offer a pad with the mounting hole marked.   Stuff manufactured more than 10 years ago tends to be a lot harder - with trial and error on the height and a bit of luck in precisely locating the mounting hole along the centerline of the car. 

Don't worry about the close clearance between the axle and screw.  That's normal.  Sometimes, however, the axle has a bit of flash from the molding process that needs to be trimmed off with a hobby knife.  Occasionally, just because of tolerance issues, an axle will rub against the screw.  In these cases, I take a dremel with a fine tapered grinding wheel and thin down the center of the axle a very tiny bit.  This situation is very rare, however.   The other solution is to order some 3/16 or 1/4" 00-90 flat-head screws from Walthers or some other source (N Scale Supply has them, I think).  The flat-head screw is "fluted" and will sit absolutely flush with the bottom of the coupler box (the mounting hole is already countersunk for this kind of screw).  I don't know why MT doesn't supply these kinds of screws to begin with - I guess they are slightly more expensive than the round-head ones they give you.

If you need any conversion help, e-mail me directly at jdcolombo@gmail.com.  Happy to help - I've converted just about every kind of rolling stock made by every manufacturer out there, except for well cars and some other very modern equipment that doesn't fit my layout timeframe.

John C. 

[bill pearce]

The other beauty of body mounts alongside reliability, is the fact that shims are not necessary. Simply carefullt take a file to the bolster and lower the car to a correct ride height.

[Mark5]

The only test of this hypothesis that I can do is to back a train of MTL heavy weight passenger cars (with body mounted coupler from the factory) around my layout to determine if they work without causing derailing.

Some of the MTL heavyweights have the truck pivot points closer to the center of the car, which is poor design in my opinion. Since there was a choice, it would have been far better to have the pivot points closer to the ends of the car, thus minimizing coupler overhang on curves.

I think Skip re-located the truck pins on at least one of his MTL HW cars. That's what I want to do too.

Mark

[rogergperkins]

John C., thanks for the additional details and hints.  I am accustomed to using the assembled versions of the MTL couplers.  I do not see an assembled version of 1027 listed in the MTL database of exploded coupler diagrams.

I noticed the couplers I used have a small peg on the shims which appears to help align them with the two holes on the MTL cars.
I also placed an MTL boxcar load in the car to which I mounted one body coupler.  More testing.

[randgust]

Very little of this holds true with any of my own experience, except the stringlining.

I have about 95% truck mounts and have no intention of changing, although I've gone on a fairly agressive campaign of body lowering through the construction of new bolsters.

As a part of regular operations, I have to back several 20+ car trains through an Atlas C80 #5 crossover between mains.   I do it slowly and carefully, the only problem has been excessively light cars such as MT 55-ton hoppers on the front end.   But no habitual derailments.  So I've dismissed the entire arguement of truck-mounts causing excessive derailments as long as you touch up points and gauge.   If you do have rough switchpoints and frogs, yeah, you're definitely going to derail more.

I am using original MT wheels, not low-pros, with a few test exceptions.   There's a lot more meat in the flanges.  I'd be curious to hear how many that are having trouble with truck-mounts derailing are using low-profiles.

I've liked truck mounts because they keep the couplers in geometry alignment with the trackline center for coupling and uncoupling and I used 100% delay uncoupling as well.    I've mixed in some body mounts, all went fairly well until I got the first BLMA F89J flat and it stringlined and fell over anywhere near the front.  Never had that problem before with MT flats, or Alan Curtis, or Con-Cor, the car is heavy enough, we're talking on a 15" radius curve with 20 cars trailing.  I haven't concluded that it's due to the body mount on an 89' car but now I'm wondering.  I just demoted the car to end-only service.

I have a bunch of newer cars with body mounts and other than the long cars, no noticeable problems other than coupler alignment if I'm trying to couple or uncouple anywhere near a curve.

I'm just not convinced, that's all, and because I think the truck mounts do a better job of keeping the coupler aligned to the track centers (vertically and horizontally) for delay uncoupling - particularly on long cars - well, sorry, just as usual, I'm the contrarian. 

[rogergperkins]

I am neither an advocate of body mounted couplers nor am I against them.  I have two type of cars that came with body mounted couplers: MTL heavy weight passenger cars and FVM wagon top boxcars.

I found Mr. Kelly's article of interest because of the simple idea that back a string of cars was a way of testing couplers among other aspects of a layout.

Now the topic has listed the pros and cons. 
Maybe time to let sleeping dogs lie.

[randgust]

I'm an old IBM mainframe guy decades past and I have a 25-year old son that's a software engineer at MIT.  He's got several sayings he's fond of and I've adopted including 'the problem with standards is that everyone has their own', and my new favorite 'the problem with variables is that they change!'.

There's a lot of variables here to isolate.  This forum in particular is full of doers instead of thinkers, so I don't dismiss anybody, I'm just dumping in another dataset here. 

The unintentional benefit of struggling with this early on with truck-mounts on the 89' cars (the original long-shelf MT's) had HORRIBLE results, mostly with vertical pull-aparts and/or pin snagging, not backup derailing, and led to my Fitzgerald-led modifications on coupler faces (aka RDA couplers).   People actually frutzing with this stuff off the grid have made some big-time contributions.  We really are our own test labs here.   

[robert3985]

I've been body mounting couplers and lowering cars since I bought my first N-scale MT car waaaaay back in the 80's.  I've also been running lo-pros since then, which I cut myself when MT wheelsets were two plastic wheels and one metal axle.  I started using MT Z-scale couplers as soon as I discovered them after testing a few in long 60+ car trains and finding they worked just fine by themselves and mated up to MT N-scale couplers.

I run maximum train lengths now of 30 40' cars on my home layout due to my passing siding lengths, and I don't back up whole trains a lot through complicated trackwork.  I also handlay all of my turnouts to tighter standards than RTR turnouts, and my minimum radius is 24".

I also snip off the "dongles" on every coupler as I don't use the "Magnematic" function as I prefer to uncouple cars using an uncoupling pick.

Frankly, I don't see any operational difference between talgo mounted coupler or body mounts.  I do it for appearance's sake and it works just great for me, as do lo-pro wheelsets and Z-scale couplers.

I suppose it might be different if I was using RTR turnouts or sectional track or running extra small radii, but I'm not.  I'm also really anal about smooth, permanently attached trackwork, so that might have something to do with my near total lack of running/derailment problems.

Ahhh...body mounted Z-scale couplers,...vs body mounted N-scale couplers...

[Nick Lorusso]

I've been using body mounted couplers for a while and just started switching couplers to Z on my cabooses for now. Only issue I have with the z couplers is that they seem not to stay closed. I'm using the stock screw that comes with the package of 905s. Any suggestions?

Nick

[robert3985]

I've been using body mounted couplers for a while and just started switching couplers to Z on my cabooses for now. Only issue I have with the z couplers is that they seem not to stay closed. I'm using the stock screw that comes with the package of 905s. Any suggestions?

Nick

I've never had that problem Nick.  However, I'm thinking you might be torquing the screw too much.  It's a trade-off between torquing the screw tight enough so that the coupler doesn't rotate vs making the coupler stiff. 

To make sure I get both a well-functioning coupler and one that doesn't rotate, I put a very small dab of Walther's Goo on the coupler body before I screw it in, being careful to not allow any Goo to work its way into the holes in the top of the coupler box, and I also squirt Kadee Grease-em or any other graphite dry lube into the coupler body and work it around a bit.

Here's another coupler on a much modified/superdetailed brass Hallmark "welded UP" caboose (CA-8, CA-9).  You'll note that I almost always paint my couplers, as shiny black isn't prototypical in my experience.  A nice, warm gray is perfect and it doesn't impair their function, but ya gotta be semi-precise with your paintbrush to keep wet paint off the surfaces that slide against each other.

[Nick Lorusso]

I've never had that problem Nick.  However, I'm thinking you might be torquing the screw too much.  It's a trade-off between torquing the screw tight enough so that the coupler doesn't rotate vs making the coupler stiff. 

To make sure I get both a well-functioning coupler and one that doesn't rotate, I put a very small dab of Walther's Goo on the coupler body before I screw it in, being careful to not allow any Goo to work its way into the holes in the top of the coupler box, and I also squirt Kadee Grease-em or any other graphite dry lube into the coupler body and work it around a bit.

Here's another coupler on a much modified/superdetailed brass Hallmark "welded UP" caboose (CA-8, CA-9).  You'll note that I almost always paint my couplers, as shiny black isn't prototypical in my experience.  A nice, warm gray is perfect and it doesn't impair their function, but ya gotta be semi-precise with your paintbrush to keep wet paint off the surfaces that slide against each other.

Thanks Bob,
I'll give that a try.

[Cajonpassfan]

I use Z scale body mounted couplers on all my rolling stock (about 150 cars/locos) and have never had any problems.  I even ran a 50 car train to see if I would have any issues with derailments or unwanted uncouplings, but couldn't get anything to come uncoupled or derail.  Normal train length for me is 18 or so cars.  Backing isn't a problem either.

I'm a big advocate of Z scale couplers on N scale rolling stock. 




Erik

Eric, that's some seriously nice work...!
Body mounted 905's? Do you have grades and if so, how many cars before you get uncoupling problems?
Thanks,
Otto K.