N-Possible Coupler Announcement (Nashville 2022)

[Ed Kapuscinski]

I had a chance to test a train of these on the Modutrak layout at NMRA Novi.  Wow. 

Modular layouts, even Modutrak, can sometimes have some messy joints that test coupler's verticle range.  So the big question was, will the smaller scale coupler head have any issues separating at module joints. 

Watching these couplers navigate joints, I'm impressed by their ability to hold at the outer edge.  But it makes sense.  There's no draft angle to contend with, like a Micro-Trains coupler.  And they arn't made out of slippery engineering plastic.  So they hold at the edge even better, despire their more scale height.  Add in the lack of coupler bounce, and these will ultimately prove to be more reliable I'm sure. 

There's an arguement to be made that these are better than MTL even for the N-trak and FremoN modular layout runners.  And that's pretty impressive. 

Oh man, I think I might need to add a "what people are saying" thing to the website now.

And yes, I agree 100%.

[turbowhiz]

I had a chance to test a train of these on the Modutrak layout at NMRA Novi.  Wow. 

Modular layouts, even Modutrak, can sometimes have some messy joints that test coupler's verticle range.  So the big question was, will the smaller scale coupler head have any issues separating at module joints. 

Watching these couplers navigate joints, I'm impressed by their ability to hold at the outer edge.  But it makes sense.  There's no draft angle to contend with, like a Micro-Trains coupler.  And they arn't made out of slippery engineering plastic.  So they hold at the edge even better, despire their more scale height.  Add in the lack of coupler bounce, and these will ultimately prove to be more reliable I'm sure. 

There's an arguement to be made that these are better than MTL even for the N-trak and FremoN modular layout runners.  And that's pretty impressive.

I do a live demonstration of this at my booth at shows; I'll get a video produced one of these days.

The NP joint here holds where the MTL joint slips when you tension the cars, every single time, even though there is considerably more vertical gathering surface with the MTL joint. The interesting thing I find (since I've done this probably over a 500 times now in public) is that the amount of force required to get the MTL joint to slip is quite variable. It sometimes holds to a very high force, well in excess of any reasonable train length, and sometimes fails at a very low force. But it consistently gives up first.



(it fails with short shanks on the MTL side too.. The booth demo I use 3 PS-2 hoppers)

Sorcery? No, just good design.  Another significant factor aside from the material and lack of draft angle is the N-Possible lapped knuckle shank... It adds a lot of strength to the knuckle shank and helps it stay straight (and therefore the knuckle itself stay in vertical alignment). As well, since the actual joint is a whole lot closer to the car(s), you have a whole lot less leverage on the shank itself too.

All these factors combine to create a significantly more reliable joint, even when stressed on the outer limits of the gathering range.

[Rasputen]

I could only put in one type in my cart. When I added another (medium) to the existing (short), the CVR shopping cart replaced the exisitng item with the added. I tried several times and just kept ping-ponging back and forth with the result of only having the latest addition of one item in my basket.

I had this same problem - I even tried another browser with the same result.  I think it is related to the "Keep Shopping" button.  I had to go back to the CVR main screen and continue from there in order to get everything I wanted in the cart.

[Jesse6669]

@turbowhiz this is really looking good.  Very exciting, and hoping for a US source before long. 

Do you have a photo comparison to MTL Z couplers?  I could swear this has come up before but I can't find it.  I'd love to see how these look on a Z-scale car.

[robert3985]

@Jesse6669 - For the comparison between MT 906/903's here's a quote.  It's on page 32 of this thread...

My 905's showed up. Well, technically 903's, which needed to be assembled. I'll say that there is absolutely no comparison with respect to the ease of assembly of my couplers vs the 903's. Or any other MTL coupler to be honest, but the 903's are just that little bit more "fun".

It looks like my scalebox short shank parts should just work in any place you've installed a 905. The slack in coupled distance will be shorter on account of the head slack alone, and the slack out coupled distance will be longer, but all in the same range with the same hole placement. One major benefit of the NP coupler is that you can have much tighter coupled distances by account of the minimal slack action. If you have a high slack design, you will have a collision when the slack is in even if you're slack out distance is correct.

The NP box is longer towards the front by about .3 mm. The NP box top is just a hint thinner (like .05 mm).

The NP scalebox is shorter then a stock 905, even when accounting for clearance, and would work in places where you've shortened the 905 box too. There is much less width at the front, but conversely there is width needed for clearance of the coupler spring levers on the NP coupler that's not needed on the 905.

The NP spring design allows for much shorter overall length then the MTL longitudinal design (you do trade width behind the pivot point for this, but its a good tradeoff). I will have future designs that will be significantly shorter overall then this launch short shank design which will come in handy in certain scenarios. Like carbody diesels with minimal truck clearance for example.

There is absolutely no comparison with respect to off center slip resistance. The NP couplers compare favorably with traditional N scale MTL couplers in this respect, the Z scale couplers aren't even in the same league.


Top view slink in:



Top view Slink out (ignore the trip pin I'm using to hold the slink...)



Side view slink in:



Side view slink out:
 


End View (note that the top ridge on the scalebox is cosmetic, and can be easily removed if desired)

Cheerio!
Bob Gilmore

[GaryHinshaw]

More important, what do you recommend for M1.2 taps?

Amazon has a pretty substantial collection of M1.2 taps.  That said, the M1.2 specs are very close to 00-90; the main difference being that 00-90 has 90 threads per inch while M1.2 has ~100 per inch (a 0.25 mm pitch).  As a test, I tried threading an M1.2 screw into the 00-90 threaded hole in the MT-1055 gauge and it fit just fine, so in a pinch, a 00-90 tap would probably work for most metals.



For holes in plastic, I just drill a #63 hole (0.37" = 0.95 mm) and let the screw tap the threads.  This has been working very well in my scale box installs.

I had a chance to test a train of these on the Modutrak layout at NMRA Novi.  Wow. 

Completely agree.   This weekend I just had my 4th operating session since starting my conversions.  We moved and switched about 500 cars, including ~200 N-P equipped cars and they just work, full stop.  Such a joy.

[Maletrain]

As Gary posted, the M1.2 screws have 101.6 threads per inch, compared to 00-90 screw's 90 threads per inch.  The diameters are very similar, so screwing an M1.2 into a hole threaded for 00-90 will surely work in plastic.  Like Gary, I don't even bother to tap holes that small in plastic - I just drill a hole the size specified to be tapped and let the screw threads serve as the tap as I screw them into the undersized hole.

But, metal might be a different situation.  I would expect an M1.2 screw to jam in a metal hole tapped for 00-90, if driven in far enough.  But, with the amount of "slop" in the fit of screws in tapped holes, I expect an M1.2 could go in a few turns without jamming.  It only takes about 3 thread pitches of (proper) engagement for screws to hold well, so maybe the shallow holes we use for mounting couplers would work.

I don't have any 00-90 nuts handy.  If somebody on here has a 00-90 nut and an M1.2 screw, please see how many turns the screw can go into the nut without jamming and post the results.  If not, I'll try to tap a hole for 00-90 when I get back home tonight to do the test.

[Lemosteam]

I have put these in plastic and metal.

BTW- you can make your own tap by grinding a groove into the thread with one edge parallel with the centerline of the screw, with the open shoulder pointing in the direction of the tightening direction.

I buy 100 packs of the flat head screws on ebay.  They are the same as mentioned above. and the seller offers all of the lengths you would like.

https://www.ebay.com/itm/183914679946?var=691608951011

The eBay store also has stainless versions of these.



Also has the wafer head in stainless.

https://www.ebay.com/itm/135064585530?

[GaryHinshaw]

I don't have any 00-90 nuts handy.  If somebody on here has a 00-90 nut and an M1.2 screw, please see how many turns the screw can go into the nut without jamming and post the results.  If not, I'll try to tap a hole for 00-90 when I get back home tonight to do the test.

In the photo above, the screw is threaded all the way through the hole in the gauge with no real resistance.  I'd guess the hole has ~6 threads.  Evidently the tolerances are pretty generous.

Thanks for the ebay link John.

Added - I located a 00-90 nut and it does not thread much more than 1 turn on the M1.2 screw.  The MT gauge threads must be somewhat loose.  Stick to matching screw and thread specs wherever possible, especially in metal frames.

[Lemosteam]

Good metric taps should also be readily available. I bought a low budget set a while ago, and they are sweatshop grade, lol.

https://ebay.us/m/qEnOWm

[garethashenden]

Good metric taps should also be readily available. I bought a low budget set a while ago, and they are sweatshop grade, lol.

https://ebay.us/m/qEnOWm

While I am generally of the belief that its worth spending a bit more on good tools, I cannot suggest that anyone spend the hundreds of dollars that top tier taps cost for this use.
Maybe the $30 that McMaster wants, but no more than that.

Tapping is a complicated subject tangentially related to my job. Lots of factors in selecting a tap aside from thread and cost; material, blind or through hole, cnc/hand tapping, etc. But for a few train cars here and there cheap should be fine.

[nscaler711]

I am definitely excited to see these, I do wonder if there will be a version that are a bit shorter in the box for the tighter fit of locomotive pilots (so trucks can swivel properly) or even cars whose trucks sit further towards the ends off cars like bethgons and RD-5s.
They doo look pretty narrow which is great since the 1015 boxes are so wide and don"t allow trucks to swivel on some tighter radii. 

[robert3985]

I am definitely excited to see these, I do wonder if there will be a version that are a bit shorter in the box for the tighter fit of locomotive pilots (so trucks can swivel properly) or even cars whose trucks sit further towards the ends off cars like bethgons and RD-5s.
They doo look pretty narrow which is great since the 1015 boxes are so wide and don"t allow trucks to swivel on some tighter radii.

@nscaler711 - Page 30 of this thread should fully answer your question as to what N-P coupler will be closest to fit your needs.  Turbowhiz has also posted measurements in this thread...so browse the thread and your measurement questions will be answered.

Additionally, the N-Possible website is up with excellent product photos and explanations here: https://www.n-possible.com/

Cheerio!
Bob Gilmore

[Lemosteam]

While I am generally of the belief that its worth spending a bit more on good tools, I cannot suggest that anyone spend the hundreds of dollars that top tier taps cost for this use.
Maybe the $30 that McMaster wants, but no more than that.

Tapping is a complicated subject tangentially related to my job. Lots of factors in selecting a tap aside from thread and cost; material, blind or through hole, cnc/hand tapping, etc. But for a few train cars here and there cheap should be fine.

Boy did I screw up that post.  The linked taps are NOT the crappy ones I bought.  That is a decent set for ~$8.

[ednadolski]

It looks like my scalebox short shank parts should just work in any place you've installed a 905.

This is good news for Z scalers -- I have some 905s in my AZL SW1500s and they will really benefit from a low-force, no-slink coupler 

Ed