This is how they are able to operate on 36" radius.

I close the gap with Kadees.

Or in 3 rail O-72 that magic radius we all hear about.

John Johnson explained to me some easy math regarding our tight turns to run railroads in a relatively small space.

Reality a 16 degree minimum on the Union Pacific used on reversing Y's just for example. Slightly tight for mainline use is in o scale 2 rail an equivalent is 90" radius.

Some 3 rail figures compared to 2 rail.

O-108 Diameter
54" radius

O-72 Diameter (full circumference)
36" radius in 2 rail from center point to edge

O-120 minimum to run my new Key FT's are 60" radius.

I hope that makes sense and yes to most review.

Changing coupler location is of course the secret.  You want to pick a minimum radius, try it with two cars, then convert your fleet.  74" radius is not quite enough for me to run an SP articulated coach with correct spacing.  I had to add a sixteenth of an inch.

 

From my limited diaphragm experience, I think paper is the best.  I use metal strikers and paper bellows.  Cloth works well for full width diaphragms, but I only use those on articulated cars.  Both hold paint well.

 

I have had zero luck with rubber diaphragms.  Their shelf life is quite limited.

Update:  I'm taking advantage of having a few of my CZ cars apart while performing the window upgrade to evaluate the best option for Kadee installation.  I'm planning on using the usual 2mm screws but at 12 or 14mm in length with nuts and lock-washers affixed on top to secure the resulting coupler box/shim sandwich to the metal floor.  The floor already has well-placed holes that are too big to tap 2mm screws and the Kadee box doesn't accommodate larger diameter screws which is why I'm using bolts/washers. Doing it this way should bring the cars approximately .400 closer.  I chose against gluing the plastic shim to the floor bottom and forcing 2mm screws into it as I may want to disassemble it in the future and I prefer a mechanical fix if one is available and within my skill-set.  I had to order the longer screws and hope to have them next week.  If there's any further interest let me know and I'll be happy to share my results.  Chris

 

Atlas,

 

Please know that my only criticism here regarding your gorgeous CZ cars is the user unfriendlines one encounters installing Kadee couplers.  I believe I speak for others here as well, please give us better options when it comes to couplers.  

 

Thank you,

Chris Cinque

An opinion:

 

What's really needed on cars like these is what's called "kinematic close couplings";  these are couplings that have 'draft gear mechanisms' that sense the curvature, and increase the car to car distance accordingly -- on straight track the distance between diaphragms is minimal.  These have been available in European HO [ because of the buffers ] for years;  Kato [ who else ! ] is putting them on their recent HO and N Superliner / Daylight passenger cars;  and they are usually on the "Lenz" coupling which predominates on European RTR 0 gauge equipment -- MTH Euro freight cars [ and the Rheingold cars ] w/ scale wheels have them.  

 

For cars such as the CZ a dummy Tightlock is suggested;  the CZ would have been an ideal set for these, since I believe it generally ran as a block over its route.  Obviously pads for KD's would be an in-the-box option.

 

Best rgds, SZ

 

 

 

 

Gents,

 

 First photo: The car on the right has the Kadee.  The only 2mm screws that I had which were long enough for now were 16mm in length, I'll try 12's or 14's when they show up next week.  All that I need to finish is the nuts and lock washers.  The holes in the floor while being well placed are too big to tap a 2mm screw.  The next photo shows Atlas coupler on left vs. Kadee on the right two.  Last two photos show spacing difference with Atlas OEM vs. Kadee mod.  Not sure what minimum radius will be now but I suspect 60" won't be a problem as the diaphragms easily compress a little.  This mod didn't require a lot of work and the .400 closer spacing is far more pleasing to my eye.  I wouldn't want to bring the spacing any closer as it would probably result in the diaphragms coming in contact more often and while they look good they are fragile.  

 

Christopher

 

 

 

 

 

 

STEINZEIT wouldn't it be better to just run them on larger radius track? to make these or any full length passenger car look realistic a minimum of 60"(o120) curves are necessary. the bigger the better i run 84" RADIUS. a complex coupler mount will only increase the cost and then we will hear more whining about Atlas!!!

 

Certainly.

 

SZ

What's really needed on cars like these is what's called "kinematic close couplings";  these are couplings that have 'draft gear mechanisms' that sense the curvature, and increase the car to car distance accordingly..<snip>..- MTH Euro freight cars [ and the Rheingold cars ] w/ scale wheels have them. 

Interesting. I wonder if MTH makes them available in their parts dept. And, if so, could we adapt them to our passenger stock.