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Discussion Starter · #1 ·
This may not be a problem for most people as admittedly I can be very rough with my equipment, however over the weekend I did manage to break a coupler off one of my Jackson & Sharp coaches.  We were backing one car behind the engine into a string of cars and gave it a decent  jolt, which broke the coupler mount off of the front end of the car behind the engine.  I do see a potential problem with they way they are mounted that may lead to problems in the future due to rough handling and/or fatigue.

The coupler box is only mounted to a cast post sticking out of the car floor.  The post is ~5/8" long and 1/4" diameter and is the only method of attachment for the coupler box.  My coupler broke off where the post meets the floor.  Sorry for the blurry pictures but I hope they're enough to show what happened.

The coupler box with the mounting post still attached (to the left rear of the picture).  Please note as well that the coupler is not mounted to the box in any way as well.  A pin (barely visable in the right front of the box) rides in the coupler shank and the whole assembly holds the shank against the end sill.  No bolts/screws hold it to the box.


The area where the post is cast with the foor.
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

Ouch! That does look a touch problematic. And not something a longer screw would fix. I suppose you could probably drill some holes in the plastic "walls," thread some wire through, and tie the coupler box to that to add some strength. I'm cutting my platforms off and building new ones, but I'll have to still keep that in mind.

Later,

K
 

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I think that you could probably get a fix that would be sturdier than the orginal by placing a flat head machine screw down through the top of the platform and then through the broken post. Then fill over the top of the screw head with some epoxy.

John
 

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I've already failed one by accidentally running one train into the back of a J&S consist sitting on a siding.  The post is plastic and sheared right off.  I was actually lucky, I only broke the one.   This is definately a weak point on these very nice cars.  Other AMS stock use a metal post to secure the coupler.  The good news is that the right amount of epoxy fixed the problem. 
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

I haven't had this problem, but I have had springs come out of the couplers after running for a while. I went looking for them and noticed they popped out at the end of my 9' diameter curve.
 

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Discussion Starter · #6 ·
I plan to epoxy the coupler pocket back in place.  If that doesn't work I'll epoxy and pin it back in place as EBT suggested.
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

Would replacing the coupler with a Kadee help?
 

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Posted By jimtyp on 02/21/2008 10:05 AM
Would replacing the coupler with a Kadee help?


No.  It's the mount that failed, not the coupler.
 

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Discussion Starter · #9 ·
The only way I see a Kaydee helping is if you remove the post on the cars and building a solid platform for the new coupler box to mount on. 
 

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I had the same problem with a broken coupler post in late January, just before we left for Arizona.  The train became uncoupled and the K ran aroung the loop and slammed into the rear of the coach.  There were several cars in the train, including a brass Accucraft post office car.  This was a fairly heavy train so perhaps that is why mine broke. 

I'm planning to fill the area around the post with epoxy when we get back.  I probably won' t do it to all of the coupler pockets.  I'll just fix them on a when needed basis.

Chuck N
 

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I noticed this response from Accucraft about the J&S coupler problems. One to Twenty Point Me.com.

It looks though Accucraft will be incorporating a design change into future releases of the cars.
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

Gary

Making a "fatter" post to put the screw in hardly constitutes a "design change". The design suggested is the same, just a bigger mass of plastic to shear off. Making a cuopler box that could have horizonal screws in it from the side to resist the shear forces would be a design change.

Did it not occur to them that these cars might be in between some of their own relatively heavy brass San Juan cars? E=MC**2 and all that other physics; you know, Newton's Laws of Motion. I think they have not yet been outlawed in California (home of Accucraft), and might still appy even if they had been declared illegal in Berkley because they interfered with the basic right of particles to have unrestricted freedom of movement and the right to assemble.

Cheers

Jim
 

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Jim,
I agree that the "fatter" post is NOT a design change. I was just noting that Accucraft was atttempting to solve a bad problem. I received two J&S coaches last month and took a quick look at them. It seems to me that somebody wasn't really thinking when they made this post so weak. The plastic cars are fairly heavy, let alone putting them in a consist of brass cars. One thing for sure, the larger and heavier rolling stock in 1/20.3 is starting to test the strength of these couplers.:D
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

Gary

The big failing with the Accucraft couplers (and the "DUMB" Kadee design it copied) is the elimination of the sprung draft gear that is in a Kadee 820 / 830, which of course goes all the way back (in US model train manufacturing) to the cast O scale dummy cxouplers of the 1930s and 1940s. Kadee put in their original MK-4 HO and it became pretty much there standard design in all the scales. The Accucraft and "short box" Kadees use spings on the side that only provide for pivoting in the horizontal plane. It does almost nothing (useful) in properly absorbing the shock of cars running together.

Turn over one onf the new Bachmann 1:20 tank cars. Has a coupler box that matches a Kadee 830. But it has a solid shank coupler with "whisker" (an HO coupler term) centering springs. There is nothing in the train to absorb the "Buffing" forces of cars runing in and out as speeds change and gradients change. This isn't such a big deal in N and HO. But the S and O scale coupler guys are sticking with draft gear springs because of the mass of the cars.

The "springs on the side" design is easy and convenient. It may even work reliably for a few lightweight "G" geight cars. But it really stinks for these heavy 1:20.3 cars and locos. What we need is an Accucraft coupler grafted onto an 830 shank, or a real friction plate draft gear assembly like the prototype.

Just my opinion

Cheers

Jim
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

Gary

( "G" geight cars ) rhymes with ( "G" freight cars )

Jim
 

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RE: POTENTIAL Accucraft Jackson & Sharp problem

The larger limitation of the Accucraft coupler pocket design is that it has far less side-to-side play than the "standard" Kadee coupler pocket. On long cars (especially passenger cars) this can be a major issue on tighter radius curves, and particularly on S curves going into a siding. I'd love to see Accucraft switch to a larger coupler pocket on their rolling stock. There's no reason why it can't be done. These are large cars with plenty of room for such things.

Later,

K
 
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