Best Of Notes on body-mount couplers (work-in-progress)

[ednadolski]

I've been working on getting a drawing together, and it is almost ready to go.   It looks like the cost should work out to $2 per fret.  Each fret has 8 parts, and since one car needs 2 bodies and 2 covers, that works out to $1 per car.  There are a total of 8 different types of frets, as this picture shows:





(IMPORTANT: please note that this drawing supersedes any/all previous lists, so be sure that you refer to the parts from this drawing.)


To go ahead with an order, what I need is for all interested persons to please send me a list of exactly which parts you want, specifying the quantity for each type.  I'd like to submit the order in two weeks, so please have your requests to me by then.   The drawing may need to be revised based upon how the request numbers work out. Once the parts arrive (and look OK) then I'll notify everyone, and you can send the payment (paypal) for the parts + whatever shipping you prefer.   I expect the order will take about 2-4 weeks after placement.

As always, if you have any questions or see anything that I've overlooked, by all means please let me know.  I'm glad to work together on this, it's exciting stuff! 

Cheers!
Ed

[bbussey]

To clarify -- this etched pocket only accepts the bowser coupler?  Accu-Mate and McHenry couplers will not fit?

[GaryHinshaw]

That's correct Bryan - the dimensions are specifically intended for the FT couplers.  The design would work just as well with Accumates and McHenry's if the pocket dimensions were adjusted.   Ed might be willing to do that, or provide the artwork for someone else to do that.  But he has the latest files, so I'll let him respond.

-Gary

P.S. This design will not work well with MT couplers.

[GaryHinshaw]

Ed, this looks like a great way to package the parts, and I think the price is turning out to be quite reasonable.  I'll make up my wish list and send it to you off line.

Just to add a few comments about some of the questions raised:  the body and cover styles are interchangeable.  The only difference between the two cover styles is the air hose length - consult your prototype.  The choice of body length requires a bit more thought, and since we've only completed a handful of installations between us, we don't have an MT-style conversion sheet prepared.  But here are some rough guidelines:

* cushioned under-frames required the long body.
* many other installations benefit from the long body, e.g. mounting couplers to tank car tanks, rather than end platforms.
* similarly, many cramped installations will benefit from the short body.

For reference, the overall length of the short body, when assembled, is 0.300" from the back of the spine to the front of the pulling face; the long body is 0.350".  Both can be trimmed to a shorter length, but that can mean opening the back of the slot (which I have not found to be a problem).

The shims are strictly for convenience when fine-tuning coupler height.  It is useful to have pieces cut to the same size and shape as the box, but they are not needed for many installations (and/or you can easily fashion your own).   IIRC, the MT height gauge specifies an under-frame height of 0.266" for MT body mounts, while these boxes want 0.246" to maintain the same coupler height as the center of the MT (and prototype) standard.  In practice however, I often lower cars and/or have situations where I don't end up using a shim.  YMMV.

Let us know if you have any other questions.

-Gary

[bbussey]

Some thoughts before you jump into this without a bungee chord:

• Do you plan on marketing this product, or just making it available to Railwire members who request it?
• How readily available are the Bowser couplers, how reliable are they, and how do they perform coupled to the other brands?
• You tested the coupler assembly under simulated load, but did you test it under load in practical use while connected to additional coupler assemblies as well as other coupler brands, and through various trackage configurations?
• Did you test the coupler assemblies through S curves to test side-to-side action and confirm the equipment remains on track?
• Did you test the coupler assemblies on long cars with short wheelbases, such as the Greenville 60' boxcar, to confirm the equipment remains on the track?
  
• Did you test the coupler assemblies behind long wheelbased motive power with body-mounted couplers through various radii trackage to confirm the equipment remains on track?
• Why not design the coupler pocket to accept Accu-Mate and McHenry couplers if the dimensions are not adversely affected?
• How do you uncouple the Bowser couplers without touching the cars, with a RIX-type tool?

[DKS]

Why not design the coupler pocket to accept Accu-Mate and McHenry couplers if the dimensions are not adversely affected?

Not possible. Completely different internal geometry.

[jagged ben]

Some thoughts before you jump into this without a bungee chord:

...

Bryan, I know it's a long thread, but I'm pretty sure most if not all of the answers are there if you read through it.

[bbussey]

I've followed the thread throughout.

[GaryHinshaw]

Many of these questions have been covered, but this is a sprawling thread, so I'll collect the answers here for ease of reference.

   • Do you plan on marketing this product, or just making it available to Railwire members who request it?

Speaking for myself, the only plan at the moment is to make them available to interested parties on a co-purchase basis through this (and subsequent) announcements.  The only serious testing that has been done is on Ed and my layouts with selected equipment, where they have performed extremely well.  If a plan to market them as an actual product develops, we will need to do more testing, especially on the minimum radius questions.  But this is a niche item that will never generate large sales numbers, and I have neither the time nor inclination to get into the manufacturing business.  I can't speak for Ed in this regard though.

At the moment I would only encourage anyone interested in trying them to purchase a small lot for testing before committing to a significant purchase.

   • How readily available are the Bowser couplers, how reliable are they, and how do they perform coupled to the other brands?

The good news - which makes this scheme feasible at all - is that Bowser has agreed to sell the couplers as a separate item for $1 per pair.  See this post for ordering details:

https://www.therailwire.net/forum/index.php?topic=21980.msg309136#msg309136

The couplers themselves are extremely reliable.  The most comprehensive review I'm aware of (outside of this thread) is by DKS:

http://jamesriverbranch.net/clinic_2.htm

For my money, they are the best coupler available in N or Z, period.  Their shank design is very similar to the McHenry, but they employ a cast-on leaf spring for closing the knuckle, instead of a separate coil spring (and they are about half the size). They will mate well with MT, Accumate, McHenry and Kato N couplers (and MT Z couplers).  See, for example:

https://www.therailwire.net/forum/index.php?topic=21980.msg206847#msg206847

Caveat: to mate with an MT you have to physically lift one coupler over the other (similar to a Kato-MT mate), but they touch-mate to all other brands.

   • You tested the coupler assembly under simulated load, but did you test it under load in practical use while connected to additional coupler assemblies as well as other coupler brands, and through various trackage configurations?

Yes.  These two videos show examples: 13 to 16' long trains being pulled up a 2.3% grades through ~18" radius curves.  The leading cars are FT equipped (with these pockets), the rest of the train is a random mix of 4 brands, including some FT's:

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I have not tried them under significantly heavier loads (steeper grades, or longer trains) but these tests were fairly extreme relative to my needs.  Inspection of the couplers during these tests gave me no reason for concern whatsoever: the couplers showed no sign of deformation under stress nor any tendency to ride up or down relative to its mate (the latter being helped by the snug pocket dimensions).

   • Did you test the coupler assemblies through S curves to test side-to-side action and confirm the equipment remains on track?
   • Did you test the coupler assemblies on long cars with short wheelbases, such as the Greenville 60' boxcar, to confirm the equipment remains on the track?
   • Did you test the coupler assemblies behind long wheel-based motive power with body-mounted couplers through various radii trackage to confirm the equipment remains on track?

Yes, but only to the extent I needed to for my application.  For example, I have mounted extended pockets on some Red Caboose 62' beer cars (which have a short wheelbase).  These performed fine with 18" radius curves (including S curves), but have not been tested on sharper curves. Similarly, I have run standard-length equipment behind locos with body-mount couplers through 18" curves with no problems.   (Note: I did have an issue with AZL couplers in extended pockets causing neighboring cars to derail on S curves, but those couplers are much stiffer side to side.)

Like any body-mount campaign, minimum radius will have to be considered by the user on a case by case basis.  But the FT couplers in these pockets have almost the same side-to-side flexibility as an MT coupler, so they don't really present any new challenges in this regard.

   • Why not design the coupler pocket to accept Accu-Mate and McHenry couplers if the dimensions are not adversely affected?

Sadly, the dimensions are not compatible.  If the box were sized for a McHenry, for example, the FT coupler would have no centering tension, and it would sag in the box.  One of the beauties of the FT coupler is that it accommodates a closer-to-scale draft gear.  But again, a trivial resizing of the design would accommodate Accumates & McHenry's.

   • How do you uncouple the Bowser couplers without touching the cars, with a RIX-type tool?

Yes, manual uncoupling is achieved with a Rix-type tool. Magnetic uncoupling was not able to be made workable by the FT developers.

-Gary

[GaryHinshaw]

I should add that there are larger issues associated with the performance of body-mounted vs. truck-mounted couplers that have little to do with the specific coupler brand, especially with 89' flats and auto-racks.   In my experience, when these cars are at the head of a long train, the body-mounted cars will tend to string-line when going around curves upgrade (even 18" curves), and the truck-mounted cars will tend to derail going downgrade due to torsion on the trucks.  (This experience is based entirely on MT-equipped cars).

I have not yet committed to any single approach with my longer equipment, until more testing can be done.  But again, this is not germane to the FT couplers, and I don't wish to debate the larger question in this thread.

-gfh

[ednadolski]

Hi  Bryan, just to reiterate what Gary wrote, I don't have any intent to market or productize these pockets.   I'm happy to make this available to interested folks, but at the end of the day it's really still just a research project.  At present I don't have an interest in doing this sort of thing for any other coupler, partly due to time limitations but also since IIRC the Accumates & McHenrys will fit in the rectangular brass tubing anyways.

Ed

[bbussey]

Very good gentlemen.  It sounds as if you've considered all of the options.

[Denver Road Doug]

One question...can you post the information about the mounting hardware and where to order it from.  Assuming, just a screw or two and possibly styrene rod?   And also maybe the appropriate drill/tap set.

Better yet, maybe order a bajillion of them and offer a handful of them as another $2 component?   Pretty sure this isn't something any typical hobby shop is gonna carry, so ALL of us will be ordering them from somewhere, no?

[Denver Road Doug]

Assuming, just a screw or two and possibly styrene rod?

TWSS.

(Figured I'd beat y'all  's to it.     )

[GaryHinshaw]

The accessories needed are minimal:

* a stock of 00-90 screws (pan head or round head). 
  Walthers has quite a variety as do numerous other suppliers.  (You might want some 00-90 nuts too, but I haven't used any yet.)
* a 00-90 tap. 
  Walthers and MT both offer these, among others.
* Drill bits:
  #64 or 65 to make a tap hole in the car body. 
  #59 or 58 to make a clearance hole for the styrene rod (see below). 
  #55 for a 00-90 clearance hole (if needed).
* 0.040" styrene rod,
   e.g. from Plastruct.

I have been going through some installations with the last fret and I was thinking I would write some coherent notes on suggested techniques and will post them here in a day or two.

HTH,
-gfh