New N scale Tie System from Central Valley Model Works

[wcfn100]

Judging from the last pile I saw at ME, your samples are probably from the same batch!  I've seen the proprietary drawing of the Code 40 rail profile, including the manufacturing tolerances noted for a production run to be acceptable.

So, do your pieces measure more than .040"? Sure.  But the nominal design dimension is definitely .040".  With a manufacturing tolerance above and below the .040". Same goes for the width of the rail. 

Just a bit of trivia for you...

Well first of all, let's stop using the term 'nominal' because that has nothing to do with the actual measurement.  Or we can agree that code 40 (.040") is just a nominal dimension while the actual dimension is .043". 

Second, maybe 'batch' needs to be quantified.  Is that 10 years worth of rail being sold? More?  How often do they need to re-run c40 rail?

I have three packs of ME rail all bought at different times.  On top of that, I have 3 packs of rail from Proto87, which, if that's just repackaged ME (of from the same manufacturer), makes 6 different packs, bought at different times, that all measure the exact same .043".

I'll try and grab a new package at Caboose next time I'm there.  If it's actually .040", I'll amend future posts.  If it measures .043" like all the rest, well then - *insert Archer quote*.   

But in the overall picture none of this matters.  All my rail is c43 and there's nothing that can change that fact.

On a total side note, I may have to dig through all the packages in the future for the .037" unicorn rail that you've now put into possibility with those  +/- 9% acceptable tolerances you saw on the drawing.   

Jason

[Sokramiketes]

Ok, the "specified" dimension is .040".  There is an acceptable tolerance in manufacturing.  Your rail measures .043 high at what error in measurement?  (just kidding, I don't care  )

Your final assumption of .037" rail being acceptable is in error.  As is your 9%. FYI.

[wcfn100]

Ok, the "specified" dimension is .040".  There is an acceptable tolerance in manufacturing.  Your rail measures .043 high at what error in measurement?  (just kidding, I don't care  )

Your final assumption of .037" rail being acceptable is in error.  As is your 9%. FYI.

Sorry,  7.5%. 

I used to work in manufacturing and work with drawings.  I remember tolerances on the drawings as +/- an amount.  If +.003" is acceptable, I don't see why -.003" wouldn't be.     I've never seen one's that were different for + than - but maybe that was just for my place of work.

Of course now we're way off the mark.  I'm going to call my rail what it measures because that's what code means.  I seriously don't see the big issue with that. If I get some c40, I'll call it that.

My official statement from now on will be -

"Depending on the the batch.  Micro Engineering track can vary from code 40 to code 43."

Alright?

Jason

[wcfn100]

I've been thinking about trying this product and using the PECO code 60 rail.The plan is to make a photo diorama.Only I don't have a clue as whether the code 60 would work in these tie strips.

Anybody have any thoughts on the idea?

If you can tell me what the rail base measures, I can try and give you an idea if it will work.  ME c55 rail fits snug, basically a press fit.

Jason

[sirenwerks]

Perhaps this is a moment of stupidity, I admit publicly, again, my long-standing armchair status and that it's been so long since I have actually laid track of any type.  And I imagine I am about to throw purists into a tizzy, but if code relates to rail height and slighter quality at the railhead itself, why not just make the base the same dimension on all codes to keep the railhead centered?  And if the slighter quality creates enough dimensional shift to effect wheels staying on track, offset the rail on the base to make up for that?

[Sokramiketes]

Sorry,  7.5%. 

I used to work in manufacturing and work with drawings.  I remember tolerances on the drawings as +/- an amount.  If +.003" is acceptable, I don't see why -.003" wouldn't be.     I've never seen one's that were different for + than - but maybe that was just for my place of work.

Of course now we're way off the mark.  I'm going to call my rail what it measures because that's what code means.  I seriously don't see the big issue with that. If I get some c40, I'll call it that.

My official statement from now on will be -

"Depending on the the batch.  Micro Engineering track can vary from code 40 to code 43."

Alright?

Jason

+/- varies all the time.  One prime example you're familiar with is the NMRA standards.

http://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-3.2_2010.05.08.pdf

I apologize for pushing you into a guessing game as to what the actual specs are, as I can't share.  I shouldn't have brought it up.  I just wanted to point out that they are aiming for true .040".  Actual manufactured product varies.

[peteski]

Another example I seem to recall where the positive and negative tolerances are not equal is in the inside-diameter specs for hypodermic tubing.

[wcfn100]

I just wanted to point out that they are aiming for true .040".  Actual manufactured product varies.

I understand that and I'm not knocking them because it's not exactly .040".  And I'm not trying to start a crusade by referring to it as c43. 

I guess to be honest, I do have one thing I am trying to crusade.  I would like to see even smaller smaller rail around .035" and the strongest argument against this is generally that it's not worth it because we already have c40 and that's not enough of a difference in size.  If it were to turn out that ME rail constantly measures out on the plus side, I can take some of the weight away from that argument.

Jason