# Back to back flange measurement



## Duncan (Jan 2, 2008)

Just need a verification that the measurement needs to be 1.57" nominal. 
Did my memory function properly, or have I deluded myself once again???


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## Greg Elmassian (Jan 3, 2008)

If you are following the G1MRA standard 1.574". 

Evolving standards point to 1.582" as things are "tightened up"... 

You might find this page entertaining: http://www.elmassian.com/index.php?option=com_content&view=article&id=85&Itemid=95 

Regards, Greg


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## Curmudgeon (Jan 11, 2008)

1.575", + or - .010" is what I've used, others looser, like .020". 

If the enema-ray says change it, tell them where to put it.


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## Greg Elmassian (Jan 3, 2008)

What guardrail flange width do you use TOC? 

Greg


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## Curmudgeon (Jan 11, 2008)

Immaterial, as long as the check gauge from wing to guard is 1.535" 
I find I do not set for the clearance, rather the check gauge.


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## Greg Elmassian (Jan 3, 2008)

Works out the same, as far as I understand.... thanks... 

Should I regauge if I am using DCC? 

Greg


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## Curmudgeon (Jan 11, 2008)

Yes. 
I think there is a Tony's Special Track and Switch Gauge for dcc users. 

Conversely, I hear some inventor/self promoter wants "special" gauge issues, probably for dcc. 
But only if some Lense can have it first. 
Not sure what that means. 

First option for most LSers will be the "special" track for 1:29, to remove it's illegitimacy. 
The new "standards" will be forced upon the manufacturer, with threats of some "ray" enforcement that mimicks some medical procedure, followed by the statement "get on board or get left behind", and then statements posted on some obscure, self-righteous group's website that states "manufacturers WILL adopt this standard". 

It's a slippery slope, but we have to start somewhere, and since dcc users seem to really think so highly of this inventor/self promoter, why not put the ring through their noses first and lead them off?


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## lownote (Jan 3, 2008)

How DO you adjust the gauge anyway? How do you actually move the wheels? Greg, I see on your website you use an arbor press--that'd do it, for sure, but space is tight in my little shop and for me it'd be a one-purpose tool 

Can you make a jig and tap the wheels/axles with a light hammer to adjust gauge? 


Do you need a set of calipers, or is the aristo track gauge thingy enough?


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## Torby (Jan 2, 2008)

I have a cheap digital caliper I got from EBay for like $15. 
Most wheelsets are easily adjusted by hand. Just grab one wheel in each hand and pull firmly while twisting. 

For others, you need a little equipment: 










I was widening it a little. The clamp is to keep it from going way too much when it budged. I think I used it to squeeze them back together just a hair after they moved.


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## John McGuyer (Jan 2, 2008)

The 1.582 dimension is if you are using narrower wheels such as Gary Raymond's semi scale versions. 

John


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## Gary Armitstead (Jan 2, 2008)

Somebody on the forum made a wheel-puller/compressor from small c-clamps, to do this work. I think it was JJ. Maybe if he sees this, he can comment.


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## tbug (Feb 16, 2008)

Of the AMS wheelsets needing adjustment, I simply held one wheel while slightly pulling/ twistng the opposite wheel. No need for tools (other than a gauge or caliper).


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## aceinspp (Jan 2, 2008)

Guard face and guard check gage in the frog must both be in compliance to make things work. These have been off on a lot of turnouts. Later RJD


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## Greg Elmassian (Jan 3, 2008)

Tom, your picture is scary! I have images of wobbly wheels! 

Back to back has nothing to do with thinner wheels, might make a bit of difference, but the turnouts are the area of attention. I worry more about guardrail flangeways, but it is really the check gauge as TOC said. 

Regards, Greg


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## John McGuyer (Jan 2, 2008)

Greg 
I think you need to contact Gary Raymond and get updated. 
John


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## Greg Elmassian (Jan 3, 2008)

About what? 

That back is more important? Or thinner wheel treads? (keep the track gauge good) 

Let's discuss here.. I'm interested in what you mean. 

Regards, Greg


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## Curmudgeon (Jan 11, 2008)

The problem is, the nmra ignored LS for literally decades. 
They want to change things now. 
Ever look at the new prototype profile on the K-27? 
That's where we're headed. 
Using a check gauge isn't that big a deal. 
I won't. 

As long as: 
The track gauge needs to stay unchanged, the frog wing to guard needs to stay the same, and the existing flanges needs to stay close. 
There is someone now in charge of the nmra wheel and track standards WG who has brought the process to full stop while they determine what is out there. 
In the meantime, I would encourage the nmra to go stuff.....ooooops...I mean, go away.


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## John McGuyer (Jan 2, 2008)

What I mean is that when Gary started making the thinner semi scale wheels, the 1.575 backside on them started giving problems with the frontside. So Gary recommended the 1.582 dimension for those using them. I had some problems with them slipping off the track to the inside until I went to the wider dimension. 

John


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## Curmudgeon (Jan 11, 2008)

One of the reasons nobody around here even uses Gary's wheels anymore. 
Just think about the existing 1.535" wing to guard clearance. 
The 1.582" is almost .050" wider than the switch check gauge. 
Also, the upper limit of the nmra existing spec. 
Anything more than about .024" guardrail to stockrail clearance, and you'll be picking the point of the frog. 
You play with the back to back with existing wheelsets and turnouts, you're asking for problems. 

And, if you're going to use those wheels, you should probably look into the finescale nmra specs. 
Like, for track and turnouts. 
You are mixing fine and coarse.


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## Greg Elmassian (Jan 3, 2008)

I've collected the standards I could find, and also contrasted them with the gauges I could find: 
http://www.elmassian.com/index.php?option=com_content&view=article&id=85&Itemid=95 

As TOC said, you have to match apples to apples. Finescale wheel with tinplate standards won't work. 

After reading, talking, listening, more reading, more listening, and experimentation, I lean more towards the proposed spec of 1.582" but I set my check gauge and flangeways appropriately, again more towards the proposed specs. This means I have to examine and modify my turnouts, but they are all Aristo, and had to be modified anyway! 

Regards, Greg


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## pdk (Jan 2, 2008)

Interesting, to me. For years, as I have built my own switches, I must decide whether my Aristo/Hartland-powered locos go through smoothly, or my locos with LGB bricks. But I can't please both. It's a tight squeeze or sloppy fit for one or the other.


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## Curmudgeon (Jan 11, 2008)

And yet, using primarily Llagas, which is set to G1MRA specs, all my Bachmann, LGB, visiting Hartland, USA and older Aristo locos go through just fine. 
When you get locos that are 1.530" back-to-back, you've got a problem, and it ain't the trackwork. 

Even my Magnus, once a couple of errant wheelsets were set to G1MRA, works just fine.


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## pdk (Jan 2, 2008)

Just measured to confirm, with a digital caliper. 

My Aristo and Hartland bricks are 1.561 

My Lehmann Porter blocks are 1.544 

You wouldn't think that matters, but it does, especially since I use real rail for my check rails, and not thin pieces of metal or plastic. Therefore, unless I file away part of the foot, the gap between the rail heads is no less than .135 -- assuming code 332 rail.


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## Curmudgeon (Jan 11, 2008)

And, all my Llagas use real rail, also. 
But it's 250 and 215.


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## lownote (Jan 3, 2008)

Ok, so a simple question. On a layout using mostly aristo locos/rolling stock with a bachmann annie and some bachmann coaches, code 332 rail and a few LGB switches, to what figure should I set the back to back flange spacing?


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## Greg Elmassian (Jan 3, 2008)

I can't (in good conscious) give a simple answer. I have mostly Aristo and USAT with an Annie and shay. But, I was unhappy with the performance of longer trains and the operation of my Aristo switches. 

So, I picked a back to back combination AND modified my switches. I'm pretty much following the G1MRA, but with tighter tolerances (they used to have tighter tolerances also). Making that decision worked for me. 

Maybe you don't want to modify your switches. Or maybe you don't want to (or cannot) regauge your locos. 

You really need to look at the whole picture AND decide how much effort you are prepared to go to. 

I could make a recommendation, but I would really encourage people to read a bit more on standards, how stuff works, and pick a solution they will be happy with for a long time. Just throwing out a number is not the solution, in my opinion. 

Regards, Greg


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## Curmudgeon (Jan 11, 2008)

1.565" to 1.582". 
But, check your wing to guard rail for 1.535".


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## samevans (Jan 3, 2008)

Two simple points 

i) Regardless of values, scale or gauge the simple rule is btb plus nominal flange width should be the same as or slightly larger that gauge minus the flangeway width. The whole point is that the check rail for the rail opposite the switch frog (crossing) should prevent the flange striking or passing the wrong side of the frog. 

ii) In order to maximise good running everyone for a given scale/gauge should use the same complementary set of values (unless you are a finescale wiz) for wheels and track. 

Manufacturers have a tendency not to play to ii) in order to tie you to their track and train products. This is why 'independent' bodies like GIMRA and the NMRA promote sets of values for manufacturers to adhere to should they so desire. 

Large scale has flumoxed NMRA because different scales are run on the same trackage by Large scalers. 

Finer scale standards which is what the indoor modellers tend to work towards is also not appropriate unless you have a lot of money, engineering skills and patience. The outdoors is a less forgiving environment which one has less control over, and varies widely depending on where one is. This militates against fine track and wheels. As I said it is not impossible, but not for the average joe. 

The sensible solution would have been to apply GIMRA ordinary standards to all mass manufactured LS items running on 45mm. These standards are known to work and have been used world wide. This would allow interrunning between scales. 

NMRA could then have legislated for finescale standards for each scale for which aftermarket conversions and other items could have been made by small specialist companies or clubs/societies/ associations dedicated to a specific fine scale approach. 

Of course this is the real word so the NMRA wants to call the shots in the US and impose standards where none are really needed. Manufacturers are reluctant to adopt standards which may mean more direct competition with a rival. Kudos to Bachman for using GIMRA ordinary standard for their 1:20.3 n3 range, I hope they have the courage to stick with it. They are reasonably close to scale in that scale gauge combo and are yet practical dimensions for the garden.


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