Error in MTL Coupler Diagrams Document?

[peteski]

I was looking at the mounting height of the 1015-1 coupler in https://www.micro-trains.com/publicfiles/mtl_couplerdiagrams.pdf and the dimensions given for the shimmed version makes no sense to me.  Here is an excerpt.



If the unshimmed mounting height is 0.293", then adding a shim on top of the coupler box would result in the mounting height being higher than 0.293", but the diagram of the shimmed version shows mounting height as 0.279".

Assuming the shim is 0.014" then the mounting height of the shimmed coupler would be 0.293 + 0.014 = 0.307" (not 0.279")?  Right?

[Chris333]

I know because I type it in my computer so much. I use .280". I meaused a car with MTL truck mounted couplers to get that.

[peteski]

I know because I type it in my computer so much. I use .280". I meaused a car with MTL truck mounted couplers to get that.

Are you saying  that the coupler with the shim mounts onto a car floor that is 0.280" over the rail-head?  So is the height (0.293") of the coupler without the shim incorrect in that drawing?  One of those 2 dimensions must not be correct?

[Chris333]

Well I used the old eye ball with a pair of calipers to arrive at that number. I think the MTL drawing you showed does not account for the coupler sagging in the box a little.

But yes I use .280" with no shim and it matches a MTL truck mounted coupler. I also find the the MTL coupler height gauge doesn't match their own cars so I don't use it.

[Narlie]

Flip the numbers
No shim 279 with shim 293
Diagram appears wrong.

[peteski]

Ok, thanks Narlie.

Chris, my question was specifically about the document itself.  I was just looking over that doc, and those dimensions did not make sense. 

@MTLJoe -- Should that be corrected?  I just downloaded the latest version of that document and I also have one that is several years old, and they both show the same error.  Actually 1016-1 drawing also has the same error.

[thomasjmdavis]

Ok, thanks Narlie.

Chris, my question was specifically about the document itself.  I was just looking over that doc, and those dimensions did not make sense. 

@MTLJoe -- Should that be corrected?  I just downloaded the latest version of that document and I also have one that is several years old, and they both show the same error.  Actually 1016-1 drawing also has the same error.

If they change it, all our old coupler packaging will be more valuable as MTL misprints.

[Maletrain]

I agree that it looks like it is simply a misprinted document, with the dimensions swapped between the 2 diagrams.  Swap them back and it all adds up, literally.   

The only question is whether that is right, in reality.  Does 0.279" from the top of the coupler box to the top of the rails really result in the center of the knuckle being 0.216" above the rails?  Or, are there other errors afoot in this, too?

(I'm only asking because I am too lazy to go measure it myself.)

[thomasjmdavis]

I took a look at the instructions included in a package of 1015s from my parts box.  Those instructions show the shim in use correctly (that is, on a car with a .293 ride height).  So, at least at some point, they had the documentation correct.  I do note that on my pack "reverse draft angle" is spelled out, as opposed to the use of "RDA" shown in the version @peteski posted, and mine are -001, rather than -003 .  So mine are probably an older version.

[nkalanaga]

As Tom says, the documents in the coupler packaging are correct: 0.279 without a shim, 0.293 with the shim.

In my case, I use a no-shim mounting height of 0.275, the same as a 1025.  The difference is less than a scale inch, and makes it much easier to measure.

[peteski]

As Tom says, the documents in the coupler packaging are correct: 0.279 without a shim, 0.293 with the shim.

In my case, I use a no-shim mounting height of 0.275, the same as a 1025.  The difference is less than a scale inch, and makes it much easier to measure.

Ok, thanks.  So the MTL Coupler Diagram PDF file has couple of errors in it.

[Jim Costello]

I  have just had a look at my 1995 shop counter copy of the MTL #85 Coupler conversion guide. The book shows that the measurements for the 1015-1 and 1016-1 were transposed back then as noted above by 'peteski'
Of interest though is a 1998  'Updated changes & additions to the #85 Coupler conversion  guide' is diagrams for the 1015 and 1016 couplers.The measurements for with and without shim  is  0.279" and 0.293" respectively, as they should be.
Somewhere along the line I have noted the correct figures on my copy of the guide.
It is obvious that for the past 26 + years this detail has been noted by modellers seeing the mistake and correcting their own guidelines and this has not  been passed on to MTL for correction.

Jim

[peteski]

Thanks for the historical research Jim.
I did ping MTL Joe in one of my earlier posts. Hopefully he did look at this thread, so maybe the next version of the PDF will get corrected.  Just for the record, both 1015-1 and 1016-1 have the shimmed dimension transposed.  My older version of the PDF (circa 2011) also has this error in it.

[JoeD]

Thanks for the historical research Jim.
I did ping MTL Joe in one of my earlier posts. Hopefully he did look at this thread, so maybe the next version of the PDF will get corrected.  Just for the record, both 1015-1 and 1016-1 have the shimmed dimension transposed.  My older version of the PDF (circa 2011) also has this error in it.

Thanks for the ping...we are going to fix this and check the others to see if it occurred elsewhere. 

Joe