Diaphragms on HO passenger cars

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Charles Smiley

cspmovies
I hope to open a topic on other people's use of diaphragms on passenger cars.

The photo below is of a pair of new Roundhouse 60-foot baggage cars. The were almost a full inch apart as-built. Ridiculous!

So mounting new long shank whisker Kadees in pockets setback to create a 0.4-inch spacing looks much better and I hope to find diaphragms that can operate down to 32-inch radius curves with this spacing. They need to be far more flexible that the old Walthers paper accordion types I used years ago.

SO any discussions and photos on this topic with your successes and problems would be appreciated - perhaps by many others too.
 

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jwb

Member
I haven't made a systematic study, but Walthers (i.e., the more recent plastic cars) passenger cars have spring loaded diaphragms that appear to work without causing too much trouble. American Limited Models also makes diaphragm kits that are sorta-kinda flexible. To some extent, this may need to be something you test and tweak for the conditions on your own layout.
 

Charles Smiley

cspmovies
The problem is that none of these geniuses tell you the required, or recommended, car spacing before you buy the diaphragms -- which to me seems astonishing.

There fixed...
 
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I have used three of these cars to make an approximation of the cars used at Mount Rainier Scenic Railroad (681, 901, 902). I have to agree, out of the box the spacing was horrendous. I used Sergent compatible shank couplers in Kadee boxes to shorten the gap way up. I eyeballed the position of the couplers to about where they looked like where they should go based on seeing the cars in person. The first try I got the car spacing a little close for the 18" curves on my buddy's logging layout. I plan on getting some American Limited diaphragms to fill the remaining gaps, after I widen out the spacing a little bit.
 

jwb

Member
As far as coupler spacing, you're almost certainly going to have to do your own testing for individual makes of car and diaphragm. Are the Athearn/Roundhouse cars still with truck mounted couplers? This might also be an issue. The good thing is that Kadee gives you a medium and a long shank length (short probably a non-starter.) But this will depend on the curves and switches on your own layout, what cars you have, what cars you run together, etc etc etc.
 

trailrider

Well-Known Member
For years I have used Walthers folded paper diaphrams with the plastic striker plates. On my railroad I have 18" and 20" radius curves, and with Athearn and some older 85 ft. cars mixed in a single consist, I find it necessary to leave some gap between the striker plates so they don't really contact each other tightly. I generally cut the folded paper pieces in half along the bend lines, so the diaphragms are shorter. I also bend the outsides of the striker plates slightly curved to prevent them from catching on each other coming out of the sharp curves. May not look completely prototypical, but they work reliably, and don't look all that bad. The problem now is that the Walthers paper diaphragms are out of stock (maybe discontinued???), and I have had to look on ebay for them. I have tried other manufacturers' diaphragms, but don't get the same reliability.
 

Charles Smiley

cspmovies
The car lengths, and where the pivot points of the trucks are located seems to have a lot to do with how close cars can couple on the "ruling" curve(s) on a host layout. My worse-case locations are some #8 curved turnouts on the mainline. I have about 36-inch minimum radius curves. I'd like to get down to 32-inch on a proposed layout extension. Reverse curves are little problem too - even with a tangent section of over 80-feet between them and easements into the curves. I want the diaphragms to have some spring-force against each other but not be so stiff that they push the cars into derailments. The Walthers paper accordions were really bad in that regard. They looked OK on the display shelf but they need to be replaced if there's any hope of operation here...
 

Charles Smiley

cspmovies
trailrider,

Walthers also made some great passenger car wood/metal kits. They had heavyweight roof styles you had to carve in wood and stamped metal sides. Too bad they don't offer those any longer too.
 

Charles Smiley

cspmovies
I avoid Ebay. It's an ethics issue.

I did look via your link however and they mostly are plastic 80 footers. I have a lot of those. I've decided to concentrate on 60-foot stuff of the Harriman round-roof style.
 

Boris

Beach Bum
I have used the old Walthers folded paper diaphragms on Athearn BB passenger cars with mixed success. I removed them from the cars I am currently using, because they tended to tangle on crossovers and cause derailments. I have a set of BB cars, plus an AHM-Rivarossi Pullman to upgrade, and I am considering the American Limited diaphragms on these. I will probably change over to floor mount couplers, with this project, as I want to substitute 4 wheel trucks, to more accurately represent Reading Company cars.

Joe
 




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