richhotrain What's the point of all of this? Using the number on the package that the turnout comes in, will a #4 turnout work in a yard or won't it work? I say, it will work. Rich
What's the point of all of this?
Using the number on the package that the turnout comes in, will a #4 turnout work in a yard or won't it work?
I say, it will work.
Rich
Rich, I tried using Atlas #4's in my yard years ago, but my operational plans call for mainline steam to pull trains in andout of randomly assigned arrival and departure tracks.
My steam roster is pretty conservative size wise, but my 4-8-2's did not like the Atlas "#4-1/2", a true #4 would be a disaster, and I doubt #5's would be reliable either.
Sheldon
richhotrainSo what?
your long wheel base loco rides fine (no derailments) over a #6 turnout from one manufacturer. so you think it will do fine with a #6 fom another.
but that lead length from the other manufactures is shorter, which you think is great. but it requires a smaller radius closure rail which your long wheel base loco has a problem with.
greg - Philadelphia & Reading / Reading
richhotrainWhat's the point of all of this?
understanding why frog number does not fully describe a turnout.
why turnouts from different manufactures are not interchangeable.
and why #4 turnouts from one manufacturer may fit better in a yard than others
gregc any shortening of the lead length or broadening of any section of the closure rail requires some section of the closure rail to be a tighter radius than that in the chart. making the points straighter requires tightening the radius elsewhere
any shortening of the lead length or broadening of any section of the closure rail requires some section of the closure rail to be a tighter radius than that in the chart. making the points straighter requires tightening the radius elsewhere
Alton Junction
the closure rail has to match the frog angle when it crosses the opposite angle. the values i've come up with are comparable to those in the chart from the prototype.
ATLANTIC CENTRALBut again, on many turnouts you can clearly see the "kink" in the diverging stock rail at the tip of the points, then the straight section the length of the points, then the closure radius, then the straight section parallel to the frog, not a continious curve
yes, that "closure radius" section is tighter than if the entire closure rail were of constant radius
do the math
I will try to explain more. When you make the turnout shorter, rather the the increased straight near the frog that you show, the length and angle of the points changes.
This reduces the easement effect of the points and in extreme cases then requires the diverging point to be curved.
One day, maybe I will have time for some drawings......
Greg, most turnouts, model or prototype, have points that are straight and at a low angle in relationship to the straight route, then the closure radius, then the straight frog.
The "effective" curve of the points is almost always a larger radius than the closure radius, so there is very much an "easment" effect, even if it is more in one direction than the other.
As I suggested to you once before, your drawing does not take this into account.
Do some turnouts have a curved diverging point rail? Yes.
But again, on many turnouts you can clearly see the "kink" in the diverging stock rail at the tip of the points, then the straight section the length of the points, then the closure radius, then the straight section parallel to the frog, not a continious curve.
Honestly I still don't see the point of your drawing, it is inaccurate as it applies to most turnouts.
YES, when you reduce the lenght of the turnout, you decrease the closure radius.
BUT I will say again for the 100th time, not in the way your drawing shows becuase it does not account for how the points are made on most turnouts - model or prototype.
And I don't have time draw a bunch of correct drawings to show you.
Doughlesssince the length and curvature of the closure rail plus points could be longer or shorter based upon the geometry......if there are easments built into the curved closure rail, essentially.
not sure the "easement" is the correct term to describe the curve of the closure rail.
you may have noticed that there is a unique "Turnout Radius" for each frog number in the chart i posted. that is the radius that matches the frog angle when it crosses the opposite rail. that radius is 339' for a prototypical #6 which is 46.7 scale inches. that value is comparable to the top drawing in the diagram below.
that radius can be reduced but will not reach the opposite rail when the angle matches the frog angle when it crosses the opposite rail. a section of straight track (red) or combinations of larger radius track are needed to reach the opposite rail. a shorter lead-length results.
of course the lead-length can be shortened requiring a tighter radius curve
presumably the reason for using a larger turnout is to maximize the closure rail radius for longer wheel base equipment.
it seems an ironic compromise to use a larger turnout frog number but with a compomised length resulting in a tighter radius section of the closure rail.
YoHo1975 When asking about Peco, We must first verify if we are talking Code 100 or Code 83. In code 83, Peco follows the Frog geometry they specify 5,6,8. BUT, in code 100, Peco uses Small, medium and Large.
When asking about Peco, We must first verify if we are talking Code 100 or Code 83. In code 83, Peco follows the Frog geometry they specify 5,6,8. BUT, in code 100, Peco uses Small, medium and Large.
But, even if I had simply referred to the turnout as Peco #5, isn't Code 83 implied since Peco Code 100 turnouts aren't referred to by number but rather by size and Peco Code 83 turnouts are referred to by number, not size?
Earlier in this thread, you simply made reference to Peco #5.
YoHo1975 I personally would prefer Peco #5s
I personally would prefer Peco #5s
YoHo1975At the risk of wading into some sort of pre-existing argument, Let's be clear about a few things here. When we talk about a Frog, that number literally ONLY applies to the frog itself, the geometry of the adjoining track is NOT involved in that number. Only the geometry of the frog itself. When asking about Peco, We must first verify if we are talking Code 100 or Code 83. In code 83, Peco follows the Frog geometry they specify 5,6,8. BUT, in code 100, Peco uses Small, medium and Large. they do this, because in Code 100 all 3 switches use the exact same frog. angle of 12 degrees. But the geometry of the Turnout including the track is very different for each different model. So again, when talking about turnouts, the frog is only a part of it, it's also about the track geometry around it.
Well, there is no argument really about that. There are those of us who understand and those that don't, and that's Okay.
As you know, if all producers made frogs that were exactly the same as Greg's chart, then the angle of the diverging track post-frog would be the same for each similarly numbered frog no matter who produced it.
But that would still not mean that the turnouts themselves are interchangeable, since the length and curvature of the closure rail plus points could be longer or shorter based upon the geometry......if there are easments built into the curved closure rail, essentially.
Atlas has those easments. Peco does not. And that's why the Peco turnout is shorter, but why the Atlas is better for longer equipment. Some other aspects of the Atlas are not better, so pick the turnout that suits your needs the best and learn to live with its shortcomings in other areas.
The length of the Atlas geometry, as well as the #4.5 frog angle, provides better performance than "comparable" #4 turnouts made by others, and it may compete with Peco #5 pertaning to certain locomotives that might benefit from a longer closure rail with easements.
- Douglas
Well, I have to admit that is not an issue for me. I'm just a little too OCD to use a bunch of different brands of turnouts - two or three is about my limit.
Atlas for most stuff, Walthers for slips, scratch built when need be.
I'm not a big fan of the side throw fitting on the Atlas switch. It takes room and it needs to be burried to look realistic. I only bought Peco (sprung) for my current layout and I did not regret it.
Simon
ATLANTIC CENTRALThat is a whole other topic,
it addresses the "equivalence" of turnouts -- if one can be replaced with one from a different manufacturer
gregc Doughless What you're asking is, do the manufacturers deviate from Greg's chart when they design and build their turnouts? they may have the correct frog angle, but they may deviate from the "lead length" or "frog distance" from the chart. and even the NMRA "RPs" are inconsistent
Doughless What you're asking is, do the manufacturers deviate from Greg's chart when they design and build their turnouts?
they may have the correct frog angle, but they may deviate from the "lead length" or "frog distance" from the chart.
and even the NMRA "RPs" are inconsistent
That is a whole other topic, like the fact that the Atlas #6 has the longest lead length as #6's go.
DoughlessWhat you're asking is, do the manufacturers deviate from Greg's chart when they design and build their turnouts?
they may have the correct frog angle, but they may deviate from the "lead length" or "frog distance" from the chart. the curved rail is in blue and straight in red. the curved rail radius is on the left (e.g. 47.9") the and lead-lenght in thr middle
richhotrain ATLANTIC CENTRAL Rich, are you asking why an Atlas #4 is really a #4-1/2? No, I understand the difference, but when I asked earlier if someone could post a list of frog angles on Atlas Code 83 Custom Line turnouts and Peco Code 83 turnouts, I am interested in such a list to determine if the various turnout manufacturers are not accurately stating the number of frog units on their packaging. For example, using the chart provided by greg, if the frog angle on an Atlas #4 is actually 12.40 degrees, then it is a #4.5, not a #4. Further, if Peco advertises a turnout as a #5, is the frog angle 11.26 degrees or something more or less than 11.26 degrees? Rich
ATLANTIC CENTRAL Rich, are you asking why an Atlas #4 is really a #4-1/2?
Rich, are you asking why an Atlas #4 is really a #4-1/2?
No, I understand the difference, but when I asked earlier if someone could post a list of frog angles on Atlas Code 83 Custom Line turnouts and Peco Code 83 turnouts, I am interested in such a list to determine if the various turnout manufacturers are not accurately stating the number of frog units on their packaging.
For example, using the chart provided by greg, if the frog angle on an Atlas #4 is actually 12.40 degrees, then it is a #4.5, not a #4.
Further, if Peco advertises a turnout as a #5, is the frog angle 11.26 degrees or something more or less than 11.26 degrees?
Rich, Atlas rounded off their "#4-1/2" to 12.5 degrees.
They also rounded off the #6 to 9.5 degrees, but that is almost not measureable compared to 9 degrees, 32 min.
I can't speak for PECO, I don't own any and have never worked with them.
But I did print out their full sized diagram of the #5 and layed an Atlas #4-1/2 on top, the PECO is clearly a lessor angle asa #5 would be.
I suspect no other manufacturer has taken as big a liberity as Atlas did with their #4
Yes, Douglas. Unfortunately, I don't have a Peco #5 turnout to measure the frog angle, so I am asking if anyone knows the frog angle on a Peco #5 turnout.
What you're asking is, do the manufacturers deviate from Greg's chart when they design and build their turnouts?
Would an Atlas #6, Peco #6, and Walthers (shinohara) #6 each have the exact same angle as what is listed in Greg's chart? If not, what is the exact angle of each?
We know that the Atlas #4 is off by enough that it would be better to call it a 4.5.
If you don't have a chart handy you can use these formulas:
Frog-1 by Edmund, on Flickr
Frog_0001 by Edmund, on Flickr
Frog_fig9 by Edmund, on Flickr
More fun than a Sudoku.
Regards, Ed
richhotrain Thanks, Sheldon. I must be using the wrong term when I say "frog angle". What I am interested in learning is the determination of 4.5 for a #4 Atlas Custom Line turnout. What would be the proper reference for 4.5? I see in one of your earlier replies, you referred to "units". Is that the proper term? Rich
Thanks, Sheldon. I must be using the wrong term when I say "frog angle".
What I am interested in learning is the determination of 4.5 for a #4 Atlas Custom Line turnout. What would be the proper reference for 4.5?
I see in one of your earlier replies, you referred to "units". Is that the proper term?
It is like measuring two sides of a triangle. Pick a unit, let's use 1/4".
Start at the tip of the frog, measure away from the points 4-1/2 "units", or 1-1/8".
Then, at that point, measure the spread of the two diverging rails. It will be 1 unit, or 1/4".
This kind of layout is used in civil engineering and construction because it is easier and more accurate to do in the field than using "degrees".
A Walthers #4, will have a 1/4" spread at 1", 4 units x 1 unit.
A #6 will have a 1/4" spread at 1-1/2", 6 units x 1 unit.
The chart Greg posted is more precise and reflects actual prototype numbers.
Model manufacturers often round up or down some like ATLAS did.
gregc
richhotrain Without guessing or making stuff up, can someone with actual knowledge post a list of frog angles on Atlas Code 83 Custom Line turnouts and Peco Code 83 turnouts? Rich
Without guessing or making stuff up, can someone with actual knowledge post a list of frog angles on Atlas Code 83 Custom Line turnouts and Peco Code 83 turnouts?
#4 (4.5 actually) = 12.5 degrees
That is why they make 12.5 and 25 degree crossings, to match the turnouts when making crossovers and such.
#6 = 9.5 degrees
With the matching 19 degree crossing........
#8 = aprox 7 degrees, will confirm later.
I've always assumed that Atlas selected the #4 1/2 because 9 is a sacred number to them. Their turnouts naturally make a crossover with the parallel tracks sitting on two inch centers, right? So that's 9 inches for two inches. Cut that in half for the frog number calculation of distance over 1, and there you go.
As to why they call it a 4 I figure it had nothing to do more than look like it fits in with 6 and 8.
Lastspikemike cuyama -- Atlas Customline #4 appear to be equivalent to the #5 made by three other turnout manufacturers which are routinely used in yard ladders. It's not "equivalent." It's a #4½ frog, not a #5 frog. Look up equivalent. At least one denotation includes the context in which I used the word. Also, is there a 4.5 frog? I thought they were all whole numbers.
cuyama -- Atlas Customline #4 appear to be equivalent to the #5 made by three other turnout manufacturers which are routinely used in yard ladders. It's not "equivalent." It's a #4½ frog, not a #5 frog.
-- Atlas Customline #4 appear to be equivalent to the #5 made by three other turnout manufacturers which are routinely used in yard ladders.
It's not "equivalent." It's a #4½ frog, not a #5 frog.
Look up equivalent. At least one denotation includes the context in which I used the word.
Also, is there a 4.5 frog? I thought they were all whole numbers.
Has no one explained to you what those numbers mean? You could have 4.75 frog if you want.
Just like roof pitch is described by units of rise and run, turnout frogs are described by units of run and separation.
Measured from the point of the frog, 5 units out, a separation of of one unit is a #5.
So 4-1/2 units x 1 unit is a #4-1/2 and is a larger angle and thereby a sharper diverging route.
I layed an Atlas #4-1/2 over top a full scale printout of a PECO #5, nothing "equivalent" about them at all.
I realize that the details of turnout geometry bore half of you and escape some of you, but that does not change the facts.
And that little tidbit of info is all I have time for.....