Full-width diaphragms.

[chessie system fan]

Hi all.  I'm planning on building a few passenger cars that had full-width diaphragms.  A few questions come to mind.

1.  Does anyone make any? I don't think so, but just making sure. 

2. What would be the best way to simulate one? 

[draskouasshat]

http://www.desplaineshobbies.com/store/product/44247/N-FULL-WIDTH-DIAPHRAM/

[Bob Bufkin]

I hade some years ago.  Don't remember who made them or where I got them.  They wer rubber and didn't work that well on curves.  Must have sold them or given them away.

[SkipGear]

I'm not sure what the DesPlanes diaphragms look like but the car really needs to be designed with them in mind. There needs to be some place for the diaphram to recess into in the curves.

I've done a lot of looking at the ones used on the Cincinnatian and that has what has stopped me from completing work on the car set. I can't decide how I want to make them work properly. I am pretty close to stealing the design from some of the Kato Bullet train sets or maybe even joining the cars with the diaphragms exclusively via rare earth magnets. The trainset just wouldn't look right without working full width diaphrams so until I figure it out, the train is on the back burner.

[peteski]

Both Con-Cor Pioneer Zephyr, Aerotrain, Kato Daylight diner 3-car unit (along with bunch of other European prototype models) feature operational full-width diaphragms and they are designed just like Tony says: the diaphragms are designed to go into the car bodies while the train traverses curves.  That is the only really viable option for N scale models (where the materials used are thicker and less flexible than in 1:1 trains and where the N curves are much sharper than 1:1.)

[chessie system fan]

Thanks for the link Drasko.  Predictably, there's no picture.  Anyone know what they look like?

Tony, it's actually the Cincinnatian I'm seriously thinking about doing.

Pete, incidentally, most of the trains you mention are articulated and have the diaphragm over the centered truck.  I did more digging and found that the diner in the Kato Broadway set has a full-width diaphragm.  I can't say I like how they did it though.  It looks like it's just molded in with the body.

I wonder how well something like this would work: the cars don't have diaphragms at all, but are drawbared together with the diaphragm attached to the drawbar?

I shall ponder over this, and maybe even build a test mockup later today.

[peteski]

You're right Aaron, the ones I mentioned are articulated. But in N scale, if your non-articulated cars with full-width diaphragms were realistically closed coupled, they would need the same type of diaphragm designed as the articulated models because of the very tight curves we use.  Unless you are using realistically gentle curves on your layout.... 

The problem is exasperated by the out-of scale (overly thick) material the N scale diaphragms are made of. The just can't compress as much as the 1:1 scale ones.

[eja]

Why not roll your own out of packing foam? 

The semi dense stuff used in packaging cuts easily with a two bladed electric knife and compresses enouth that it should hand the problem of curves?

[SkipGear]

Here is a shot of the diaphragms in question....

http://www.cincinnativiews.net/images-3/Cincinnatian-Price%20Hill-Avondale%20Coach%20Lounge-Restroom.jpg

and the cars coupled...

http://www.cincinnativiews.net/images-3/The%20Cincinnatian-Winton%20Place.jpg

[SkipGear]

Aaron,
 I have the cars designed and ready to go in the computer. I was going to do out of styrene with my vinyl cutter as a one piece wrap over a sub frame.

[Bob Bufkin]

Correction to my post.  They were not made of rubber but some sort of soft foam.  Looked a lot like the ones on the Cincinnatian.

[draskouasshat]

I would consider some thin black tissue paper doubled over and glued inside of the car body. It would be flexible enough i believe.

[SkipGear]

I had considered the foam idea that Bob metioned. They are sold like that for HO already. The problem is lack of weight. The foam is going to put a lot of abnormal loads on the cars and couplers. I deal a lot with foam in RC cars and anything soft enough to work would have huge grain and just wouldn't look right. The same would be true of the Drasko's idea. These were hard metal diaphragms, not an accordion type rubber connection so a flexible accordion joint would just not look right.

The Kato Bullet trains use a combination of very light springs behind the diaphragm and a kinematic coupler that allows the cars to expand their coupling distance in the curves so as not to pinch the diaphragms too much. It is a lot of engineering to make work. Maybe a job to do on shapeways.

[Sokramiketes]

I'm not sure what the DesPlanes diaphragms look like but the car really needs to be designed with them in mind. There needs to be some place for the diaphram to recess into in the curves.

The Des Plaines kit addresses your concern.  There is an extension for the car end, and then a sprung inner diaphragm.  They use the same springs as the standard American Limited diaphragm kits and work as well. 

[GaryHinshaw]

Is it accordion style?  Can we get a picture?    Any way that it might be adaptable to an Auto-Max diaphragm?

http://www.railcarphotos.com/PhotoDetails.php?PhotoID=54582