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

[ednadolski]

Would it be possible to sub part of the post with a hole for a screw to more easily mount to other cars?

Seems doable, tho I would say what I found at least with the brass parts is that the more I do, the less and less I use a screw.  I just CA them to the car body, after first assembling the coupler with a bit of 0.040" styrene rod as the pivot.  The rod simply pushes/twists into and thru the holes, and trim when done.  So far no problems with either the rod falling out or the pocket breaking off the car body.

Ed

[wazzou]

Thanks Ed. 
I just wasn't sure what kind of bond one would get with these Resins and whatever substrate they'd be attached to, be they metal or plastic.

[GaryHinshaw]

Thanks for the feedback.  I'm definitely happy with the sliding lid design (assuming my plug tweaks work as expected), and Ed has the history of the LEZ exactly right, of course.

@C855B - no bueno on the Tru-Scale compatibility, as you expected.  They actually almost mate, but the finger on the LEZ knuckle wraps around too far to engage with the Tru-Scale:*



For reference, here are a few more comparison shots to the Tru-Scale box (I don't remember if this is the short or long shank version):







The outer dimensions of this LEZ box are 5.2 mm (l) x 3.9 mm (w) x 2.0 mm (h).  The top of the box is 1.0 mm above the centre line of the coupler, so to obtain the MTL standard coupler height of 5.5 mm above the railhead, you need to mount this to a floor that is 6.5 mm (41 scale inches) above the rails (or higher).  Anything lower would require car mods.

@wazzou it would be straightforward to replace the post with a matched pair of holes and use a 00-90 screw for mounting, but the post is only 2.6 mm behind the front face of the box, so that's problematic for a lot of cars.   I think a better approach is to mimic what we did with the brass pockets: to extend the box back a few mm as a channel and mount through a screw hole in the channel.  That is probably how I will approach a generic mounting scheme.  (BTW, this particular sliding lid requires ~1 mm of clearance behind the box).   But I gather Ed has had good luck with gluing as well.

Given how easy it is to design and print custom configurations with this new printer, I haven't really thought much about a "universal" box design. Since I have so many cars to convert en masse, it is actually more efficient now to design a custom part that fits a particular car so that I don't have to fiddle with cars mods, shims, etc.  Just design, print, and install, like the Maxi-I example.  (I can't stress enough how much this printer is changing my approach to modelling.)

*P.S. I know that Jason did some nice work with a revised Tru-Scale box design, but honestly, I never really gave the Tru-Scale couplers a second look after they came out because of their lack of compatibility and stiffness, so I didn't really follow the details of that program.

[jagged ben]

Gary, that Maxi-I conversion sure is interesting.   Is that a Gold Medal Model's etched walkway on top?

Also is that an N-scale or Z scale coupler that you have on the truck-mount mated to the Maxi-I in the one photo? 
I'm sure it was covered upthread but do the LEZ mate just fine to standard MT N-scale couplers?

[GaryHinshaw]

Thanks jb.  Yes, the walkway is a standard GMM etch from the Gunderson Husky Stack set.  The interior walkways will need to be custom etched to match the Kato's, so I may draw up a new end walk while I'm at it.  Not sure yet.

The truck-mounted coupler is a standard MTL, and yes the two couplers mate fine, but it takes a bit of force in some cases.  (It seems like some of the 3rd-party MTL designs do a bit better in this regard.)  Ironically, the larger Accumate & McHenry couplers mate with the LEZ even more easily.  This overall compatibility really sold me on the LEZ couplers.

[Sokramiketes]

I'm torn on the MTL true-scale. 

Coupling effectiveness, in terms of staying coupled, is awesome.  The tight latch means that the small head is more effective than bouncing Z scale couplers (MTL variety).  I think it's the extra friction of the tight coupling.  They pull great and deal with slight height variations better.

But they don't work out of the box.  You need to do Jason's long arm fusing and cuts to get them to swing in the coupler box.  Then you have to put them in a reasonable box.  The 1015 box is huge.  It doesn't fit anywhere reasonable on a car body.  The 905 style box would be better, something along what Jason developed would be ideal in injection molded plastic.

So I get where the Bowser coupler comes in.  Do they stay coupled in long, heavy trains?  Or do they slide up and down like MTL Z scales?

[ednadolski]

So I get where the Bowser coupler comes in.  Do they stay coupled in long, heavy trains?

See for yourself:

(N.B. that's uphill, but of course the same train had to go back down again on the hidden helix, which is not in this video nor do you see the transitions between up/down grades.  I would literally let the thing just run laps, hands off and unattended.)


Ed

[GaryHinshaw]

Mike, I think Ed answered your question, but I'll second it.  I've never had a problem with the LEZ couplers on my layout, even at the head end of long heavy trains.   I don't have as many conversions completed as Ed does, but I have run cuts of 10-15 LEZ-equipped cars at the head of 35-40 car trains up and down 2.2% grades.  No problem.

Would it be possible to sub part of the post with a hole for a screw to more easily mount to other cars?

@wazzou here is an example of a box I customized for screw-mounting to a BLMA spine car.  The idea is pretty generic though.  The stock spine car has a cast-on threaded post to to hold an MTL coupler, so I filed that down, put holes in the roof and lid of the LEZ box, beefed up the lid thickness a bit and moved the back wall forward to provide more stiffness as close to the screw post as possible.  I also added a pair of flanges to the top of the box to seat into slots in the bottom of the spine, so as to avoid the inevitable twisting that occurs with generic screw-mounted boxes like this.  Here is a grab of the drawing, which took maybe 45 mins of CAD time, starting from the basic box:



The hole in the roof aligns with the old coupler post hole (which I drilled through and tapped for a 00-90 screw):



The hole in the lid is a clearance hole for a 00-90 screw which secures the coupler (the lid still has a minor fit issue that needs attention):



The flanges completely eliminate any twisting, so the screw doesn't need to be so tight that it causes the coupler to bind.  The back wall in the lid also precludes binding.    Here it is from above:




The ability to easily customize a box to a particular application like this has me 110% convinced that this is the way to go with future body mounts.   The turnaround time from concept to reality is hours, the cost per item is pennies, the quality is near to injection molding, and the customization means that the installation time is short, so converting a fleet is feasible.  These printers are nothing short of revolutionary in my book.

[wazzou]

Nice.  The corners even look nice and sharp.

[Cajonpassfan]

That is nice. Two questions:
One, do these LEZ couplers uncouple easily manually, using picks, bamboo skewers and such?
Two, how does one get one’s hands on the LEZ’s today?
Thanks, Otto

[Sokramiketes]

Mike, I think Ed answered your question, but I'll second it.  I've never had a problem with the LEZ couplers on my layout, even at the head end of long heavy trains.   I don't have as many conversions completed as Ed does, but I have run cuts of 10-15 LEZ-equipped cars at the head of 35-40 car trains up and down 2.2% grades.  No problem.

Excellent and thanks for the feedback. (You too Ed). I use them in 30 car z scale trains but the shorter, lighter cars are a completely different dynamic than n scale.

[reinhardtjh]

Two, how does one get one’s hands on the LEZ’s today?
Thanks, Otto

Received from Lee English today:

Z Coupler (only)   $1.90 per pair  minimum order 50 pair
Pay by Check or Money order only
Made out to Lee English

The couplers are not a Bowser product.
No shipping charge if USA address.

Shipping by first class mail with tracking

Thank you
Lee English
1302 Jordan Ave
Montoursville  PA  17754

[wazzou]

Thanks John for doing the leg work on that and sharing the reply.

[GaryHinshaw]

Thanks indeed John.  Good to know.  I still have a few hundred on hand, but I should probably order some more to have on reserve.

By the way, I'd be happy to share these design files, but honestly, they are so simple that it almost seems pointless.  It's really just the inside dimensions that are important, especially if you plan on customizing the mounts, adding details (which I still plan to do), etc.

[GaryHinshaw]

By offline request, here are links to the basic coupler box and basic slide-on lid, as illustrated below:



Box:  https://www.tinkercad.com/things/7Mj9rn1m28z-lez-pocket-basic/edit?sharecode=Macx_o6AhlVkpormuryPHANCkv9LwPXn_4Pc7838kV4

Lid:  https://www.tinkercad.com/things/dmz9d4NSIED-lez-pocket-lid-basic/edit?sharecode=ZJBtbmocDFekQ_BZ1BmjOR32veAjo_acNjIUEyDKx1g

I believe you need to have a (free) Autodesk account to access these in TinkerCAD, but then you should be able to copy them and tweak them to fit your needs.  I won't change this basic design, but I will definitely continue to evolve it in other files with different mount points, added details, etc.  A few quick notes:

1. For mounting with a 00-90 screw, you can replace the post with a pair of holes centred 2.6 mm back from the box face.  A 00-90 clearance hole
is about 1.25 mm.
2. The slide-on lid requires about 1 mm of clearance behind the basic box, so that should constitute a stay-out zone in your designs.
3. To maintain a standard coupler height of 5.5 mm above the railhead*, the top of this box should be 6.5 mm above the railhead.  You can design in shims as appropriate.

Enjoy, and share your work.

*P.S. I find that most truck-mounted MTL couplers are closer to 5.3-5.4 mm above the railhead.  It's a small difference from the standard, but you should test your installation for compatibility.