MTL True-Scale Couplers - Recommended Height?

[Chris333]

Same here, haven't seen my gauge in years. I just grab the nearest car with MTL trucks to check the height.

Guess I could just fix the height gauge one time and start using it, but nobody got time for that.

[C855B]

The question is "how?" on fixing the gauge accurately. At least the MT-1055 I have. It's a solid chunk of metal. Anything to reduce the height is going to require milling. Anything short of a real mill is not going to be straight, level and plumb... much less accurate. 

[garethashenden]

It would be easier to make a new gauge from styrene with a coupler mounted at the correct height than to modify the MTL gauge.

[C855B]

Agreed. Now the challenge is locating my stash of thick styrene... 

This really needs to get done. If there's one thing I am seeing right away, it's low tolerance for mismatches due to the very small coupler face. I guess that was a given. The positive, however, is with a good height match, the coupling forces are much smaller than I would have expected.

And I love how they look, especially in a lashup. Very cool. Like I needed another project, yes?

[nscaleSPF2]

I think I'm just going to use the stock 1015 coupler gage to set the True Scale height.  The knuckle faces will not be at the NMRA standard height, but at least they will be close.  It also means that I will not have to shim the True Scale couplers.

Unless Shipsure has a better plan.  Shipsure?

[Peter Amling]

I just got mine today but haven't had a chance to test them out. I have the same 1055 gauge and am surprised it's not at the right height.

Since the face is smaller why not align to the bottom of the gauge coupler instead of the center? That might be easier than building something from scratch. I'll get out my micrometer and measure what height that is on the new coupler.

[C855B]

0.216" gauge, done:



As you can see, it verified that the True-Scale short shank is a drop-in replacement for the Accumate on the Alco. Similar results on the SD24 you see behind it.

[draskouasshat]

I chose to modify the regular gauge. I base my height off of an fvm wagontop express box. Ill use this guage to set my entire passenger fleet along with passenger locomotives. After that, ill move on to the freight cars and locomotives.

Adam Draskovich
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[nkalanaga]

The problem with my old Kadee height gauge is that it's the wrong height.  It used to be right, and matched the truck-mounted couplers perfectly.  Now it says they're all too low, including the ancient Kadee trucks I still have floating around.  Do zinc alloy castings swell with age?  I've tried it on Railcraft and ME code 55, Peco "code 55" and regular code 80, and a homemade surface plate with a properly gauged slot, so it's not the track causing it to sit too high.

[chessie system fan]

Adam, maybe it's the photo angle, but it looks like your gauge coupler has a slight upward angle to it. 

[w neal]

Since I don't think anyone has said it yet.....

Is there a possibility of establishing a NEW standard?

MT couplers height now is too high.

Are there some out there who might be interested in something more prototypical in height for a more prototypical coupler?

I know the idea is fill with problems, but I just thought I'd throw it out there.

THIS!!!!!!!

[Lemosteam]

The question is "how?" on fixing the gauge accurately. At least the MT-1055 I have. It's a solid chunk of metal. Anything to reduce the height is going to require milling. Anything short of a real mill is not going to be straight, level and plumb... much less accurate. 

Gimme some dimensions that are different from the original casting and I can design one in FUD with magnet pockets and all.

[Maletrain]

0.216" gauge, done:



As you can see, it verified that the True-Scale short shank is a drop-in replacement for the Accumate on the Alco. Similar results on the SD24 you see behind it.

Given the other comments on here about some MTL coupler gauges being too tall (out of their own specs), it is not clear to me how your coupler gauge is dimensioned.  Is your stack of plastic set-up to put the center of the True Scale coupler face at 0.216" above the rail head?  If so, what is the thickness of your plastic? (0.216" to the center of the coupler face is the NMRA standard, and the paper insert that comes with the MTL gauge says it is also the MTL standard.)  I measured my own MTL gauge, and, as close as I can eye-ball "center" on its coupler face, it is at the 0.216" standard.

At this point, I am not seeing much reason to change the NMRA/MTL standard of 0.216" to the center of the coupler face from the rail head.  That is n scale for the maximum height of unloaded freight cars (34.5" according to AAR Interchange Rules, 1977).  Nkalanaga previously posted that the average height of the center of the prototype coupler faces in operation is 33", or 0.206" in N scale.  Looking at 0.010" difference in my calipers, I just don't see the modeling value in changing the standard and its gauge to make it represent the average instead of the max.  I think we should leave that issue to another day, and not burden this new product with that as well as the other compatibility issues.

[C855B]

...Is your stack of plastic set-up to put the center of the True Scale coupler face at 0.216" above the rail head?  If so, what is the thickness of your plastic? ...

Yes, 0.216". The plastic is 0.159", calculated from the box thickness of 0.114" after determining that the knuckle was vertically centered relative to the box.

I don't think anybody is disagreeing with the 0.216". It dawned on me this morning that the discrepancy with the MTL gauge may be using it on Code 55 track. I did not check with absolute certainty that the alignment dogs are not resting on spike heads, bearing in mind this gauge was tooled long before C55 was widespread. I realized this only after building my own gauge, and using 0.045" material for the alignment dogs, which did rest on the spikes!

It's not handy at the moment, but the instant I get over to the layout I will measure it on Unitrack and see if this isn't influencing our measures.

[Maletrain]

As per Prototype... That's a BIG NO-NO..   Anything over 70' can NOT be coupled to anything shorter than 45'.. (Rules may fluctuate road by road.)

It's frustrating when your building trains with Centerbeam cars and Sand hoppers..

You can have have a 69'11" car coupled to a 45' 1" car..
but a 70'2" car coupled to a 44' 10" car... 

   But Rules is Rules..

~Ian

Well, how did they couple those 80-85' passenger cars to the tenders of steam locomotives that were often in the 30-something foot range (e.g., USRA medium tender at ~33')?

More importantly, has anybody yet tried that with these True Scale couplers?  Can a Model Power USRA Light Pacific successfully pull the MTL heavyweight passenger cars around typical layout curve radii after both are converted to True Scales?  (Not suggesting they should work on 9" curves, which make long passenger cars look hideous, anyway.) And then there are the 85' stream lined car models, many of which have truck-mounted couplers.  Can medium tenders work with those after they are converted to body-mount True Scales?  (Maybe we will all need to run a 60' RPO between tender and passenger cars?)

If this is actually a problem, it would be nice to know and publicize it soon.  A truck-mounted box for the True Scales would probably be a viable solution, but there is not word that that is coming.