N-Possible Coupler Announcement (Nashville 2022)

[learmoia]

https://www.ebay.com/itm/297437730138?chn=ps&mkevt=1&mkcid=28&google_free_listing_action=view_item

So if you had the coupler against the frame of the car and custom bottom lid to hold and center the coupler... that accepted the screw from the top (gigity...).. Would that work?

~Ian

[Sokramiketes]

If the deck height is a match to the prototype, then the only other thing that could be off that much is that the draft gear should actually extend up over the deck of the car. 

So, do you want to do it right?  Better modeling through peer pressure...

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[Sokramiketes]

Ha, look at this one.  Is this a triple deck remnant?

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[turbowhiz]

It sure looks like these boxes are screwed in through the top... So do these cars work with a metal underframe underneath a complete plastic deck on top? It looks that way... To service the coupler, you need to remove the underframe from the deck?

(The trainworx gondola's have that setup. I have to say I really find that VERY annoying!)

How I would approach this conversion (based on this picture so purely speculative):
Cut the entire metal box section out of the metal underframe. And then glue a topless box onto the plastic deck. You'd need to glue it as there is not going to be enough material to put a screw in on the plastic deck (unless you go through the top but that would make for cosmetic things to deal with on the top side)

[wcfn100]

The Trainworx gondolas are the same way.

Jason

[samusi01]

Ha, look at this one.  Is this a triple deck remnant?

Not sure about a triple but definitely for racks.

[peteski]

Trainworx flats have metal underframe and metal deck.  The bottom part of the coupler box is retained by a screw installed from the top of the deck, then covered with the metal deck. The top part of the coupler box is actually in the metal underframe itself They use MTL underslung couplers.

Is the N scale MTL coupler height actually modeled to scale (is the coupler placed as 1:160 height of the 1:1 couplers).  I always thought that original rapido couplers first used in N scale toy trains were placed at some height pulled-out of a hat (or based on European coupling standards). Then MTL couplers came along, they just used the same height for compatibility and for easy rapido/Kadee coupler conversion.  If that just happens to be in correctly scaled height, that would be a bit of a happy coincidence.

[garethashenden]

Prototype coupler height is 31.5" to 34.5" from the top of the rail.

Some quick math;
(31.5)(25.4)/160 = 5.000 mm
(34.5)(25.4)/160 = 5.477 mm

N-Possible couplers are specified at 5.5mm, so a few microns over the high spec. 

[robert3985]

Prototype coupler height is 31.5" to 34.5" from the top of the rail.

Some quick math;
(31.5)(25.4)/160 = 5.000 mm
(34.5)(25.4)/160 = 5.477 mm

N-Possible couplers are specified at 5.5mm, so a few microns over the high spec.

At 5.5mm to represent the "high" height of prototype couplers at a prototype height of 34.5"...the NP's height spec comes in at a prototype height of 34.6456", a whole .1456" (prototype height) or an RCH less than 5/32nds of an inch higher than the max prototype height...

Yup, a few microns higher than max prototype height...which I converted to inches for us metric-impaired modelers.

I think I can live with that...

Cheerio!
Bob Gilmore

[turbowhiz]

Prototype coupler height is 31.5" to 34.5" from the top of the rail.

Some quick math;
(31.5)(25.4)/160 = 5.000 mm
(34.5)(25.4)/160 = 5.477 mm

N-Possible couplers are specified at 5.5mm, so a few microns over the high spec.

Rounded up .0136 mm from the NMRA (and MTL) spec of .216"/5.4864mm +- .01". I figured that 5.4864 would be better expressed as 5.5 for simplicity (less then a thousand of an inch for the non-metric minded). I guess the NMRA isn't so great at rounding, since the S2 spec says 5.48mm, but eh. So effectively the N scale coupler centerline standard is prototypically accurate, especially if you stick to the low side of specification. Of course you can set the coupler height to whatever you want, so long as you keep it consistent enough model to model its all good.

It does look to be possible to get those Trainworx flats converted without an insane amount of work by the looks of it. Certainly not an easy conversion, but not impossible. I'm thinking that getting to the OEM screw is a nightmare in the first place, and arguably the hardest part? Is the metal deck top glued to the cast metal underframe? How do you access the coupler screw?

(I know from the Trainworx gondola I converted its a nightmare to get to on those models.... The underframe was extremely well glued to the plastic body.)

[learmoia]

The Trainworx cars might might be a rare case where you need to use one of Ed's Adapters..

I've solved the compatibility issue.

(Attachment Link)

 Looks a bit silly, but works well so far.

(Attachment Link)

[James Costello]

(I know from the Trainworx gondola I converted its a nightmare to get to on those models.... The underframe was extremely well glued to the plastic body.)

I've got a bunch of Trainworx gons to do, so I'd love to see a full guide on how to do these one day.

[jpwisc]

I've got a bunch of Trainworx gons to do, so I'd love to see a full guide on how to do these one day.

I second that! I think the FVM MILW cabooses were done in the same fashion. I used a grinder to cut the screw off from underneath after plucking the coupler box off.

[Iain]

might just convert all my flats as they'll run as a unit, anyway, and then figure out some sort of dummy coupler for connecting to locomotives/cabeeses

[Altoona]

I have not seen this posted yet
https://midwestmodelrr.com/n-possible/?_kx=d_4BbIadZLroerpBz0l8Siob7PYAy0_ThOBGWWpK7XM.HSREbH
Judd Barton