N-Possible Coupler Announcement (Nashville 2022)

[jagged ben]

Things I love:
The ease of coupling
The look of the couplers, especially as compared to what comes standard.

What I don't like:
The apparent complete lack of slack I mentioned above, or at least the inability to see it in the video.  From what I read it should be around 6" per car for non-cushion type couplers which coumes out to 0.1875" per coupler, or about 1/64" per coupler and 1/32" per car.

Questions:
Are they compatible with the MT TSC? 
Just replacments for 1015 style boxes at this point?  1023 and 2004 in the works, I hope?

Bottom line... I will buy some and try them when they are made available!

[wazzou]

The ease in coupling is truly impressive.  I’ll reserve judgment on the slack until I can test that aspect.
Color me optimistic.

[peteski]

I find it amusing that after decades of complaining about too much slack and slinky effect, now people are not happy with a lack of slack.
I have not really been paying much attention, but do the other "slinkless" couplers (like McHenry, Accumate, etc.) have slack?  And where is the slack?  At the coupler shank's pivot point, or the slack is in the coupler head itself (or in both places)?

[Chris333]

Slack is hard to achieve.

[jagged ben]

I find it amusing that after decades of complaining about too much slack and slinky effect, now people are not happy with lack of slack.
I have not really been paying much attention, but do the other "slinkless" couplers (like McHenry, Accumate, etc.) have slack?  And where is the slack?  At the coupler shank's pivot point, or the slack is in the coupler head itself (or in both places)?

Well, it may not be the same people.  I've pretty much never complained about slinky effect and for whatever reason I don't see it as much as some people do.  (YMMV)   But I like to run long trains on steep grades with DPUs, and that's gonna be tricky if the train has no slack.

[x600]

Slack is hard to achieve.

And not always easy to cut, apparently.


Greg O.

[Chris333]

https://subgenius.fandom.com/wiki/Slack

[learmoia]

The drawing below is a 'scale' coupler box I started to mock up when the TCS coupler came out..

I don't recall if it's based on the museum boxcar, or the 30,000 gal tank (I took photos and measurements of both).. 

But it gives the dimension of max possible slack in an N scale coupler (not including any slack within the knuckle.)

~Ian

[John]

I won't comment on the design until I can try it out but from the videos @turbowhiz has a viable product

I think this has a real future

[Maletrain]

I think the distinction should be between "slack" and "springiness".  The problem is that springiness is not scalable to N scale from the prototype.  But, nonspringy slack should be scalable.

I don't now how the pivot point and the uncoupling mechanism are related in the Npossible coupler, so I can't make any comments on how to make nonspringy slack in those. 

But, it seems to me that a slightly oblong hole in a pivot point or a bit of extra clearance in the knuckle engagement could be used to introduce a controlled amount of slack.

I think that jagged ben has a good point about probably needing some slack to make distributed power in model trains work well, especially "pusher" helpers on long trains.

I am looking forward to buying a batch of these to try.  They certainly look much better, and seem to couple and uncouple very nicely.

But, I will need to experiment with small amounts of nonspringy slack to see how that works in actual practice, compared to the springy slack that the MTL couplers provide in large quantity.

[ncbqguy]

I am not sure why “slack” is desirable in scale.
The 1886 West Burlington air brake tests revealed that slack (and link and pin couplers had plenty of slack!!) was very damaging to equipment and contents.   They blocked the couplers to remove as much as possible and agreed it was superior.
Yes, slack allows starting a few cars at a time….but in modern railroading also results in pulled draft gear and broken knuckles.
It can result from cushion draft gear running in and out with rough train handling but I don’t think we are on the verge of modeling Cushioned Underframes.
The slop in couplers contribute to the unwanted slack action and false uncoupling.  The unpinned draft gear and springs magnify it.
The close fit of the scale couplers shows it makes a difference on the good track of the FreemoN layout.
When I was at Kato USA the second run of smoothside cars were delivered right before the local NMRA Division Train Show and North West NTRAK’s setup there.  I brought my cars to show off.  I used a retailer ramp to put the cars on the layout. The first car rolled down the ramp and then the second one coupled to it.   The third rolled down, coupled to the second, and the first uncoupled and rolled forward a bit.  The %&#@!! Cars acted like a Newton’s Pendulum and wouldn’t stay coupled on straight, level track much les rough NTRAK module joiner tracks.  The factory, without being asked or having us review the design, came up with a new, smaller coupler.   Not only was the height insufficient to keep cars coupled, but subsequent use revealed they had a self-disassembly feature.  The “repair” kits sent out weren’t much of an improvement.  The magnetic couplers that followed never got much of a customer reaction and they are still on Kato USA equipment today.
Most of the M-T compatibles/copies are pivoted and don’t center/close using metal springs. 
Why would slop/slack be desirable in N Scale?
Charlie Vlk

[turbowhiz]

Sorry for the minimal response here everyone, it’s been a lot on my plate over the past few of weeks on this whole project, nerveless my other responsibilities.

Seems that people have been most concerned about the slack, or lack thereof, so I’ll address that first:

According to this railway age article (https://www.railwayage.com/mechanical/freight-cars/mechanical-couplers) new type E couplers have 25/32” worth of slack. They would wear from there, but let’s take this at face value. That’s about 0.00488” or .125mm of slack per coupling in N scale! The N-Possible prototypes have about that much slack; Don’t underestimate just how much better model trains operate with a lower slack coupler! Yes, prototype couplers have slack. No, they don’t have coupler slack even in the same universe as traditional MRR coupler designs. Don’t confuse coupler slack with draft gear movement.

This video is a fantastic visual reference to what is going on:

Note that slack; Its not in the coupler head, its in the draft gear.

The origin of MRR couplers with massive coupler head slack, even in larger scales, is about the effective standardization of the Kadee designs and their mechanical requirement for a high amount of coupler head slack for magnetic uncoupling functionality. The classic Kadee/MTL N scale coupler has egregious amounts of coupler slack, exceeding that even of their HO scale brethren in literal never less scale measurement. And the HO scale Kadee couplers have massively excessive slack relative to the prototype as well.

Only the traditional N/Z scale “MTL” coupler has draft gear slack, in all of the MRR coupler designs I’m aware of. Kadee has done operational cushion underframes in HO, but that’s a whole other animal. And as we’re all aware, physics doesn’t scale, and well yeah, the draft gear slack spring interaction is the source of our slinky issue with MTL couplers.

The critical operational benefit of the low slack type head design is that the couplers STAY ALIGNED under buff (compression) conditions. The prototype does this, but MRR couplers of Kadee (or compatible designs) lineage DO NOT. They are unable to mechanically stay aligned at the head level (because of the massive slack), and consequently will tend to shift to their lateral travel limit, especially when a corner is encountered. The ability of couplers to stay aligned under buff allows for much more prototypical train handling characteristics, even with your models. You can effectively push any train you can pull; You can much more reliably operate DPU’s and helpers. Push-pull commuter trains work. Lightweight rolling stock is more reliable. I’d say it’s the equivalent improvement of moving from truck mounted to body mounted couplers in terms of buff reliablity. Under buff conditions: Truck mount<Body Mount<Aligned head design (body mount of course).

I respect people’s concern with respect to “reading slack” in helper/dpu type scenarios. But honestly, with couplers that stay aligned under buff, you will be shocked with just how much more “force tolerance” you have. Its massive. Operations with helpers/DPU’s are so much more reliable that you will never want to go back. I’ve operated test trains in extremes absolutely impossible to operate with traditional couplers that don’t stay aligned under buff.

I’m sure the number one question everyone is asking is “When will these be available!?” At this point, I’m actively exploring multiple avenues with respect to bringing these to market. I’m keeping all options on the table at this point. I respect that for something as crucial as a coupler, a long-term reliable supply is imperative. I can assure you - these will be coming to market!

Andrew

[oakcreekco]

Just my experience based on my little mainline pike, but N gage slack is a headache and not needed.

Nothing drives me crazier than MU'd engines bouncing back and forth while running on my mainline. It's a problem regardless if it's a DC or DCC lashup.

Now there's rolling stock, which can vary from 2 Bay closed hoppers to auto racks. They all have their own "slack traits" while running, and this varies with placement in the consist.

Based on what I run, and how I run, no slack is a good thing.

Looking forward to trying some of these out.

[u18b]

Grade makes a huge difference.

My testing of my Western Maryland Shay carrying four hoppers up and down a grade caused me to hate the slinky effect.

I like these couplers- except for no remote/magnetic uncoupling.

This is not a knock on these couplers- they look great.

But I'd probably prefer a couple with no slinky and can still uncouple cars remotely without massive hand power.

My 2 cents.

[ednadolski]

I find it amusing that after decades of complaining about too much slack and slinky effect, now people are not happy with a lack of slack.

Big difference between "slinky" and "slack".... this is the "slinky":

This too -- you can even see some of the cars even actually come to a stop for an instant.

This only happens with spring-design couplers like the MTs, I've never seen non-spring couplers do this, no matter how much "slack" might be in them.

Ed