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Frog flangeway dimensions

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Frog flangeway dimensions
Posted by Redvdub1 on Thursday, February 20, 2014 3:22 PM

I'm having a problem with some Shinohara HO double crossovers..specifically their frog flangeways are around 39 mils wide.  My NMRA Mark III track gauge has a center nub for turnout  frog flangeways that is 55 mils wide.  What's happening is that engines will at best "wobble" when traversing the double x-over...and at worst they will "lift up" and lose electrical contact (i.e. stall).

I am considering taking a diamond file to the turnouts (not the crossings) to widen them to somewhere between 45-50 mils.  Any advice/counsel is appreciated. 

George T. Galyon

Olde Newburgh Model RR Club 

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Posted by Graffen on Thursday, February 20, 2014 3:48 PM
Flangeway should be 48 thou! The nub is a no go check gauge!

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Posted by fwright on Thursday, February 20, 2014 5:04 PM

I suspect the problem is not the flangeway, but the track and check gauges.  A "tight" flangeway would pinch the flange, but would not likely cause the wheel to climb out of the flangeway.  But if the flangeway is not in the correct place gauge-wise, the wheel will have to lift as it tries to roll on the railhead.  One or a combination of several factors can cause this:

  • trucks or wheel sets out of gauge
  • guard rails not located correctly to give the correct back-to-back dimension between wing and guard rail.
  • frog not properly aligned with closure rails or extended frog rails
  • track gauge between frog point and stock rail not correct

If the frog flangeway is truly as small as you say, and the track gauge is not narrow, then the guard rail flangeway must be wider than one would expect.

A few years ago, the range for the flangeway width was 0.040" to 0.050" (track gauge must vary with flangeway width for the back-to-back to stay constant).  Turnout manufacturers generally used the wide end of the range - and sometimes exceed it.  This allows out-of-gauge wheels to pass through, at the increased risk of having the flange pick the frog point.  The wider flangeway also provides some gauge widening - similar to widening on curves - to allow trucks and drivers to take a sharper curve (turnout) than they otherwise would.

Those who hand-lay track or buy custom-made turnouts have a tendency to use the narrow dimension for the flangeway (Fast Tracks excepted).  Using the minimum end of the range reduces the amount of wheel drop, enables the use of the narrower code 88 wheels in HO without problems, and reduces the amount of slop, rattle, and wallow when wheels pass through the frog.

just my thoughts and experiences

Fred W

 

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Posted by zstripe on Thursday, February 20, 2014 6:43 PM

Without seeing your turnout and not being able to gauge it, I will suggest a test for you to do. Take a truck with wheels and every direction just slightly push the truck on it's own, through every part of your turnout and observe what it is doing, if the guard rails are too tight, it will not go through the turnout on its own. That being the case, contrary to some beliefs it will start to crawl, not from the flange at the rail, but the back side of the wheel flange where the axle is attached. The cure? make the guard rail wider by filing it. I had some Atlas #4's that had narrow guards and some of my Athearn six wheel axles BB's had that same problem, they would bind going through the guard rails, not enough to stop it, but make it hesitate. I also have the original Shinohara turnouts that had the same problem.

Frank

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Posted by Redvdub1 on Thursday, February 20, 2014 9:08 PM

Thanks for the responses.  Good to know the experience of others.  Will probably file those

turnout flangeways to around 45 mils.  Stay tuned. 

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Posted by Foamer2 on Monday, June 2, 2014 11:48 PM

Fred W.  I read your post with great interest.  I prefer to use the code 88 wheels you mention, but ALL commercial turnouts allow the wheel to drop into the frog.  Some build up the gap with plastic so the flange rides on it, but that is not right, it's a bandaid.  Even Proto 87 and Fast Tracks frogs look too long I guess is the word I want.  There must be a way to get the frog points further into the gap so that when the wheel rolls off the closure rail it rols onto the frog point at the same time.  I am inclined to build my own frog/closure rail/point assemblies, just not sure I have the ability.  Any advice?

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Posted by fwright on Monday, June 9, 2014 4:41 PM

Foamer2

Fred W.  I read your post with great interest.  I prefer to use the code 88 wheels you mention, but ALL commercial turnouts allow the wheel to drop into the frog.  Some build up the gap with plastic so the flange rides on it, but that is not right, it's a bandaid.  Even Proto 87 and Fast Tracks frogs look too long I guess is the word I want.  There must be a way to get the frog points further into the gap so that when the wheel rolls off the closure rail it rols onto the frog point at the same time.  I am inclined to build my own frog/closure rail/point assemblies, just not sure I have the ability.  Any advice?

Fast Tracks actually had a video on the subject of flangeways, explaining the relationships between the various dimensions.  I don't know if they still have it on their site, but it was quite informative.

I believe (could be wrong) Fast Tracks uses a very sharp frog point to allow the frog point to extend further into the frog while still using normal NMRA turnout dimensions.  This (reputedly, I have never used Fast Tracks) virtually eliminates frog drop.

NMRA came up with a set of dimensions (fine scale) for use with code 88 wheels.  It is still on their web site.  It was never ratified.  My understanding was that the result was not as robust as desired, or did not meet the expectations of the voters (I was not an NMRA member at the time, so this is hear-say).  The code 88 wheels use exactly the same flange dimensions as the code 110 wheels, which may or may not be a good thing.

The design principle is that the wheel width must be at least twice the flangeway width to prevent drop in the frogs.  And this might not even be enough at very large frog numbers (#10 or greater).  A code 110 wheel with an .050 inch flangeway meets this rule, as does a code 88 wheel with a .040 inch flangeway.  Code 88 wheels were developed as the narrowest practical wheel when the NMRA HO track spec had a flangeway range of .040 - .050 inches.

As I said in the earlier post, the back-to-back for code 88 wheels had to remain the same to run on NMRA-spec track.  When the flangeways are narrowed to minimum to avoid wheel drop at frogs, the track gauge also must be narrowed to minimum to keep the back-to-back the same.

There are others (Britain's OO-SF standard, Austrailian Terry Flynn, and US custom turnout maker Steve Hatch) who advocate narrowing track gauge below NMRA minimum for better performance.  My compromise for handlaid track is right at minimum flangeways and track gauge.

Hand laying track is not difficult.  The first turnout will likely not be a thing of beauty but will likely perform flawlessly if you work carefully, and keep at it until you get it right.  Fast Tracks (or P87 Stores) is a great way to get started if you lack the confidence to try it on your own.  In the mid-70s, I was a poor sailor, and couldn't afford commercial turnouts.  So using Jack Work's article, Turnouts for the Better (Model Railroader, April 1963) as my guide, I started laying my own turnouts.  And they worked on the first try, despite the solder blobs!

just my experiences

Fred W

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Posted by railandsail on Saturday, January 27, 2018 9:15 PM

Redvdub1

I'm having a problem with some Shinohara HO double crossovers..specifically their frog flangeways are around 39 mils wide.  My NMRA Mark III track gauge has a center nub for turnout  frog flangeways that is 55 mils wide.  What's happening is that engines will at best "wobble" when traversing the double x-over...and at worst they will "lift up" and lose electrical contact (i.e. stall).

I am considering taking a diamond file to the turnouts (not the crossings) to widen them to somewhere between 45-50 mils.  Any advice/counsel is appreciated. 

George T. Galyon

 

 

Just ran across this subject thread as I was looking for information that might help me with 'tweaking/modifying' a goodly number of nice Fleischmann Profi-track turnouts I had hoped to utilize on my new layout in planning. I had thought there might be some shimmimg of the 'flangeways' (both depthwise, and guard rail wise) that might help them??

I was surprised that there was no mention of the track Code in these discusiions??

Brian

 

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Posted by ATLANTIC CENTRAL on Saturday, January 27, 2018 9:38 PM

Brain,

By default if HO trackwork was actually sold in a Shinohara package, it is code 100 or code 70, in this case likely code 100.

Shinohara makes code 83, but it is only marketed under the Walthers name.

But the OP of this thread, four year ago, did not say for sure.

While I agree with what others told you about the turnouts you have in your thread on the subject, I will offer a few thoughts.

First, flangeway dept is not important, it should be deeper than any flange you would run.

Relying on the idea of model flanges riding on the bottom of a frog the way some modern prototype frogs do is a bad idea.

After that, the NMRA RP-12 dimensions should be your guide in adjusting flangeway widths.

Sheldon 

    

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Posted by rrinker on Sunday, January 28, 2018 12:00 PM

 I tried my hand at Fast Tracks, and while I have decided that hand laying turnouts is just not for me, I did manage to get a prety good oone on my first try. It didn;t look great, but mechanically it was very sound. Standard Code 110 wheels, I don't use the semi-scale ones, were able to roll through and not drop, even when exerting extra force. The frog would catch the wheel before it fully rolled off the closure rail. This was with Proto 2000 metal wheels, which are what are on all my running rolling stock. Unlike other turnouts where the wheel drops with an audible click, the Fast Tracks turnout barely made a sound, even if pressing down on the truck with far more force than a properly weighted car would exert. 

 But it definitely required that sharp frog, and even witht he tool for that, I had to make 3 or 4 before I got a good one. Same with the points. At that rate, I never would have finished enough for my previous layout, which didn't have all that many, and trying to make enough turnouts to fill a basement - I should hope to live that long.

                                      --Randy

 


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Posted by Anonymous on Sunday, January 28, 2018 1:20 PM

ATLANTIC CENTRAL
First, flangeway dept is not important, it should be deeper than any flange you would run. Relying on the idea of model flanges riding on the bottom of a frog the way some modern prototype frogs do is a bad idea.

Here you have a fundamental misunterstanding of the Fleischmann profi track turnout design.

They are designed that the wheel NEM wheel has to run on its flange. The gap between frog and closure rail is too wide to run on the tread. A RP25 wheel will fall into the gap without inserts.

Most German turnouts are designed this way. Exceptions are Tillig Elite track, Peco streamline, and Fleischmann Profi Track high-speed turnouts with movable frogs.

The Fleischmann Profi Track is code 100.
Regards, Volker

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Posted by ATLANTIC CENTRAL on Sunday, January 28, 2018 1:33 PM

rrinker

 I tried my hand at Fast Tracks, and while I have decided that hand laying turnouts is just not for me, I did manage to get a prety good oone on my first try. It didn;t look great, but mechanically it was very sound. Standard Code 110 wheels, I don't use the semi-scale ones, were able to roll through and not drop, even when exerting extra force. The frog would catch the wheel before it fully rolled off the closure rail. This was with Proto 2000 metal wheels, which are what are on all my running rolling stock. Unlike other turnouts where the wheel drops with an audible click, the Fast Tracks turnout barely made a sound, even if pressing down on the truck with far more force than a properly weighted car would exert. 

 But it definitely required that sharp frog, and even witht he tool for that, I had to make 3 or 4 before I got a good one. Same with the points. At that rate, I never would have finished enough for my previous layout, which didn't have all that many, and trying to make enough turnouts to fill a basement - I should hope to live that long.

                                      --Randy

 

 

Interesting comments. My code 110 Intermountain wheels do not "drop" in my Atlas turnouts? And that is with mostly sprung trucks. 

Careful observation shows that the wheel tread is still on the wing rail as the wheel tread passes onto the tip of the frog point, even with the blunt point of the Atlas Custom Line frog.

They are all supposed to work that way.

Older built-up frogs on the prototype work that way as well.

BUT, what does happen, to varying degrees is this.

The wheel is tappered, so as the wing rail diverges from the path of the wheel, the wheel lowers VERY SLIGHTLY. 

How much it lowers is a direct function of the wing rail, guard rail, track gauge and wheel set tollerances.

When the wheel then passes over to the frog point, it is lifted back up that very small amount.

That sometimes makes a noise with metal wheels.

But again, at no point is the wheel tread unsupported by rail if everything is correct.

Sheldon

    

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Posted by ATLANTIC CENTRAL on Sunday, January 28, 2018 1:40 PM

VOLKER LANDWEHR

 

 
ATLANTIC CENTRAL
First, flangeway dept is not important, it should be deeper than any flange you would run. Relying on the idea of model flanges riding on the bottom of a frog the way some modern prototype frogs do is a bad idea.

 

Here you have a fundamental misunterstanding of the Fleischmann profi track turnout design.

They are designed that the wheel NEM wheel has to run on its flange. The gap between frog and closure rail is too wide to run on the tread. A RP25 wheel will fall into the gap without inserts.

Most German turnouts are designed this way. Exceptions are Tillig Elite track, Peco streamline, and Fleischmann Profi Track high-speed turnouts with movable frogs.

The Fleischmann Profi Track is code 100.
Regards, Volker

 

Actually I have NO understanding of that track system and have not handled or seen a piece of that stuff since I was teen in the 1970's. Even then, I only saw a few pieces in the hobby shop I worked in. Never ran or used any NEM standard trains.

Again more reason to not try and use them with North American equipment.

I was explaining the operation/requirements of the RP-25 wheel and its relationship to a turnout.

Sheldon

    

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Posted by Anonymous on Sunday, January 28, 2018 3:02 PM

Sorry if I misunderstood you. But you said: While I agree with what others told you about the turnouts you have in your thread on the subject, I will offer a few thoughts.

Therefore I thought your following thought were about the Fleischmann turnouts.

Quote: Again more reason to not try and use them with North American equipment.

I totally agree. That is what people were trying to tell Brian on at least two forums in two threads each.
Regards, Volker

 

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Posted by railandsail on Monday, January 29, 2018 9:34 AM

Choosing Peco's

This past Sunday I did an inventory of my turnout inventory. As it turns out it appears as thought I have plenty of Peco turnouts to build my new pike with,....maybe supplemented with a few nice Roco and Atlas customline.

So I will likely sell off these nice Fleischmann ones, rather than try to modify them.

In most of my reading and research it appears as though the depth of the flangeways in turnouts is NOT a big controlling factor of derailments. It is more of a question of the widths (excessive) of the flangeways that causes problems. And these wide flangeways would be even more problematic with those thin scale wheels that I have NO intention of utilizing.
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Posted by ATLANTIC CENTRAL on Monday, January 29, 2018 3:04 PM

railandsail

Choosing Peco's

This past Sunday I did an inventory of my turnout inventory. As it turns out it appears as thought I have plenty of Peco turnouts to build my new pike with,....maybe supplemented with a few nice Roco and Atlas customline.

So I will likely sell off these nice Fleischmann ones, rather than try to modify them.

In most of my reading and research it appears as though the depth of the flangeways in turnouts is NOT a big controlling factor of derailments. It is more of a question of the widths (excessive) of the flangeways that causes problems. And these wide flangeways would be even more problematic with those thin scale wheels that I have NO intention of utilizing.
 

Good choice. 

Sheldon

    

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