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

[Denver Road Doug]

Gary, thanks for starting a thread on this.  Probably will get my vote for post of the year. 

[bbussey]

- With the rectangular tubing, what's a good way to attach this to the car body?  Can it just be epoxied on in some cases?  Also, do you ever see any wheel clearance issues with this?  (Edit:  seems possible to grind away portions of the brass tubing if they have any issues with the wheels/axles.)

You make the tubing long enough to drill another hole in the back to mount it to the underfloor with standard 00-90 screws.  The brass tubing is thinner in height than all current coupler boxes, so the axle clearance isn't an issue.

[Philip H]

SO, now that we have afix, who's got the best deal on Accumates or FT's at bulk prices?  And where are Craig's bulk truck packs???????

[GaryHinshaw]

Looks great Gary!  One other update - the method can be adapted to MTL couplers by cutting out quarter circle wedges around the screw hole to clear the coupler centering pins.

The FT couplers look intriguing.  They might be worth exploring further.  Do they come with MTL-compatible trip pins?

Thanks Bryan.  I'd be curious what tools you use to work with this tubing (especially to make an MT-compatible cutout like you suggest).  It seems like a mini-chop saw and drill press would be invaluable for bulk production.

The FT couplers were designed with auto-uncoupling in mind but, as I understand it, the knuckle spring was too stiff to allow this to work properly, so the trip pins were clipped off for this run of couplers (but there is a trip pin in there, which is used to secure and pivot the knuckle).

-gfh

[GaryHinshaw]

Awesome work Gary!

Thanks Craig.  As you can see, the field is still open; but not WIDE open. 

[Sokramiketes]

The FT coupler almost looks too small for a tank car, as the prototypes would have taller shelf couplers.   

Good info on the brass tubing though, will be good for extended draft gear on a variety of models.

[GaryHinshaw]

Nice work Gary!   Thanks for posting this.    I have a few questions:

- The FT looks great with the Athearn tanker!  What is the longest car and smallest radius curve that you have tested the FT on?

- With the set screw (a) where did you get them from, and (b)  do you ever have any issue with them loosening up over time?   Maybe a small bit of thread locker could help with that.

- With the rectangular tubing, what's a good way to attach this to the car body?  Can it just be epoxied on in some cases?  Also, do you ever see any wheel clearance issues with this?  (Edit:  seems possible to grind away portions of the brass tubing if they have any issues with the wheels/axles.)

Ed

Thanks Ed.  I hunted around the 'net for set screws and ended up with these:

http://www.fastener-express.com/1-72-x-332-set-screw-cup-point-alloy-qty-20.aspx

This outfit was very good and they have a lot of related parts to choose from too.  My experience is that once the point is hitting the roof of the pocket, there is enough tension on the threads that they stay in fine.  Thread locker would certainly be worth trying, but probably not necessary.  Be sure to get a really small Allen wrench too!

I haven't tried many cases of attaching the tube to cars yet...  :, so I cede to Bryan's advice there.  I also have not tested the FT couplers too much in the field yet, so this is definitely still beta.

-gfh

[GaryHinshaw]

Great work, Gary. I'm particularly excited that you found a very simple mounting approach (simple is always better). Congrats!

I am sorry I couldn't persuade Will to offer them separately. However, you've already shown how tricky this could be. If he had provided couplers with just pockets, you would not have had the chance to mount them the way you did, since the pockets probably would not have included the bolster. So, it worked out well that you did the beta testing; it might help lead the way to new products. Perhaps someday these will be offered separately, but I could not say when the someday might be.

David, I appreciate your help over on the Z thread.  It's only a matter of time before something like this appears ready for N scale prime time. 

This actually might be a case where an etched pocket wrapper makes sense (one with little loops to hold the air hose and a little hook to hold the cut lever).  But a set of prongs behind the pocket would be the simplest & most robust mounting point, I think...

The FT coupler almost looks too small for a tank car, as the prototypes would have taller shelf couplers.   

Good info on the brass tubing though, will be good for extended draft gear on a variety of models.

I agree on the shelf couplers!!  Credit Bryan for the tubing (Sep/Oct '07 NSR, I think it was).

-gfh

[pfs]

Great info/work as always.

[jsoflo]

As I noted to Gary in weekend update, my problem has not been overhead axle clearence, it has been the width of the coupler box on MT short shank 1015 couplers. I really want to use these trucks on my MT 3-bay Ortner hoppers (which ride very high and are an FEC necessity) but the wheels collide with the coupler box on even a large radius turn (there is little room for any sort of turn before contact by the inside the wheel with the coupler box), it appears that the more narrow the coupler box is, the more extreme the turn it will handle (of course).
How does the brass tube or Z scale Bowser coupler compare in width to the MT?
and this is a GREAT topic!!

[GaryHinshaw]

Jan, I was going to try looking at the Ortner tonight.  What min. radius are you going for with these?

-gfh

[bbussey]

... I'd be curious what tools you use to work with this tubing (especially to make an MT-compatible cutout like you suggest).  It seems like a mini-chop saw and drill press would be invaluable for bulk production.

The FT couplers were designed with auto-uncoupling in mind but, as I understand it, the knuckle spring was too stiff to allow this to work properly, so the trip pins were clipped off for this run of couplers (but there is a trip pin in there, which is used to secure and pivot the knuckle).

I haven't tried it yet, but a small milling bit in a Dremel should do it.  MTL simply cuts out that square quadrant.  I copied the MTL design for the G26 coupler pocket, but on the XIH boxcar I simply used a larger diameter quarter-circle and it works fine.  You just need clearance for the pin and it doesn't have to be perfectly shaped, as long as it stops at 180 and 270 degrees.

I love your modified design of the brass coupler pocket.  I still have a number of cushioned underframe cars to modify, and your version is easier and better than mine.  Plus, you don't have a visible screw head on the bottom face.

By the way, regarding the FT coupler, I would contact the manufacturer and see if they will sell you the coupler parts in bulk.  The worst that can happen is that they say no, which leaves you no worse off than you are now.  I have a feeling that if you explain how you're using the parts, they will be receptive.

[bbussey]

SO, now that we have afix, who's got the best deal on Accumates or FT's at bulk prices?  And where are Craig's bulk truck packs???????

FWIW, I have an overabundance of Accu-Mates.  Originally the G26 was going to have them in order to help keep the cost down.  But I mis-measured the diameter of the pivot post when submitting the last tooling modifications, and the Accu-Mate pivot hole is slightly less in diameter than the MTL 1015 pivot hole.  Since it was my mistake, it was cheaper to buy a few thousand 1015s rather than fix the pivot post diameter.  But in hindsight using the 1015 was a better outcome.

[daniel_leavitt2000]

The full throttle couplers look awesome. But I'm a little reluctant to spend $5 on couplers, $2-3 on metal wheels on a car that I already converted to MTL and MTL low profile wheels.

[GaryHinshaw]

Bryan, our Railwire liaison to Full Throttle, David K. Smith, reports that Will is unable to sell couplers separately at this time:

http://therailwire.net/forum/index.php/topic,21926.msg206220.html#msg206220

I am mostly posting the FT part of this thread to report on my tests to date and to suggest what my 'dream coupler' might look like, in case any manufacturer is taking notes.  

I certainly agree with Daniel that $5-6 a pop is too much for couplers.  But that's the price of the trucks (with nice metal wheels) plus couplers.  If there were a way for Will & Bowser to market the couplers separately, they would definitely be cheaper, and there would be a whole new market: N scale.

Cheers,
Gary