The detailed discussion Greg and I have been having relates to building your own curved turnouts, and how best to lay them out.
Since no manufacturer makes a curved turnout with a minimum 36" radius on the inner route, it is unlikely I would ever use a commerically offered curved turnout, except possibly on some piece of industral trackage.
Greg brought up some specific engineering points, and it took some expalining for me to fully convey my theory of good curved turnout design.
Sheldon
ATLANTIC CENTRALSince no manufacturer makes a curved turnout with a minimum 36" radius on the inner route, it is unlikely I would ever use a commerically offered curved turnout
Peco code 83 #7 reported specs: Length: 11-1/10"Nominal radii:-Outside 60"-Inside 36"
I have a couple of these Peco curved turnouts. I'll try to remember to draw out a 36" radius arc and see how close the turnout is in the inner route.
Rio Grande. The Action Road - Focus 1977-1983
riogrande5761 ATLANTIC CENTRAL Since no manufacturer makes a curved turnout with a minimum 36" radius on the inner route, it is unlikely I would ever use a commerically offered curved turnout Peco code 83 #7 reported specs: Length: 11-1/10"Nominal radii:-Outside 60"-Inside 36" I have a couple of these Peco curved turnouts. I'll try to remember to draw out a 36" radius arc and see how close the turnout is in the inner route.
ATLANTIC CENTRAL Since no manufacturer makes a curved turnout with a minimum 36" radius on the inner route, it is unlikely I would ever use a commerically offered curved turnout
I had heard conflicting reports about the size of those, it would be nice to know for sure.
SeeYou190Why do we need to over-think this.
not over-thinking, just trying to make sense.
there have been several threads questioning the accuracy of the spec'd radii on commercial curved turnouts.
the need for this understanding is to locate the centers of the curves on the layout the turnout is expected to lay on.
i've suggested that the curves of the turnout don't both start at the same location which i believe can explain the radii measurement, the location of the frog and the frog number.
greg - Philadelphia & Reading / Reading
Mel, that is the PECO code 100. RioGrande was refering to the new code 83 PECO.
PECO is not my first choice in track, but I would consider their code 83 curved turnout if the radius info of 36" on the inside is correct.
Thanks Mel, that is good to know.
Yes, I own two of the PECO Code 83 curved turnouts and they do have a large disparity between the outer and inner radius. The larger the disparity, the shorter the overall length of the turnout and the point rails. Peco tends to be more compact than other producers, and I'd wager that the overall length is shorter than their #8 straight turnouts.
However, I find that its difficult to use the 60 inch outer radius curve.
By contrast the Walthers curved turnouts are very long, due to the smaller difference between outer and inner radii.
For me, the 26 inch inner radius of the Atlas product is not useful in my situation.
- Douglas
Thanks Mel. I'm using the Peco code 83 #7 curved entering the staging yard and wanted to keep a good minimum for all the traffic going in and out at that point.
The Atlas inner radii would only be useful for me going into a spur maybe.
And this is the great conundrum of commercial curved turnouts, it is just hit or miss as to their usefulness in any given situation.
That's why I have developed ways to curve regular turnouts, or simply build my own curved ones.
You can disassemble an Atlas #8 and easily use the points and frog to build almost any curved turnout you need.
ATLANTIC CENTRALAnd this is the great conundrum of commercial curved turnouts, it is just hit or miss as to their usefulness in any given situation.
Maybe this issue is what finally motivates you to use a track planning program. I can't speak for all of them, but the ones I've used (XtrackCAD and 3rd Planit) match the commercial turnouts exactly.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
carl425 ATLANTIC CENTRAL And this is the great conundrum of commercial curved turnouts, it is just hit or miss as to their usefulness in any given situation. Maybe this issue is what finally motivates you to use a track planning program. I can't speak for all of them, but the ones I've used (XtrackCAD and 3rd Planit) match the commercial turnouts exactly.
ATLANTIC CENTRAL And this is the great conundrum of commercial curved turnouts, it is just hit or miss as to their usefulness in any given situation.
I think you misunderstand. The problem is that track geometry will require a specific combination of radii for a curved turnout, but no such curved turnout will exist from any manufacturer.
I don't want too sound to arrogant here, but no doubt it will come across that way, but I'm not building a model railroad based on cutting and pasting track like a train set, and with 40 years of professional drafting experiance, including some CADD, I don't need some software track planning package.
Additionally, it is unlikely that I would mix and match too many different brands of turnouts, I would just as soon build what I need.
My minimum mainline radius is 36", so far it seems only one commercial curved turnout has an inside radius that large.
Maybe if I had a full commercial CADD setup with big monitors, that might be ok, but I am designing a layout that will fill a 30 x 50 basement. That would be really annoying to do with any kind of computer drafting on my 22" monitor.
carl425Maybe this issue is what finally motivates you to use a track planning program.
while track planning software could be useful in identifying commercial turnout that would solve my problem, that isn't going to be helpful if I intend to hand lay the turnout and don't understand the geometry of the commercial turnout.
i already explained that when i built my curved turnout, i was puzzled how the frog was located so close to the points on commercial turnouts, but only figure it out by starting the curves at different locations after i built my turnout
i'm curious how things work. this both reduces cost and helps solve problems that standard practice don't solve. an engineer is constantly trying new things (not just new commercial products)
I want to clarify a comment I made earlier about "I fear the above information serves only to muddle the conversation". I was refering to my own comments, not those made by other posters. I hope nobody got offended.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
hon30critter I want to clarify a comment I made earlier about "I fear the above information serves only to muddle the conversation". I was refering to my own comments, not those made by other posters. I hope nobody got offended. Dave
No offense taken here, I thought you made an important point about being able to use regular turnouts by shifting them to the end of a curve rather than actually need curved turnouts. I actually do that a lot in my track planning.
ATLANTIC CENTRAL The detailed discussion Greg and I have been having relates to building your own curved turnouts, and how best to lay them out. Since no manufacturer makes a curved turnout with a minimum 36" radius on the inner route, it is unlikely I would ever use a commerically offered curved turnout, except possibly on some piece of industral trackage. Greg brought up some specific engineering points, and it took some expalining for me to fully convey my theory of good curved turnout design. Sheldon
I'm sure you have right, but I think is really not necessary to do pervers calculations to build a curved turnout and fit him in the trackage you ask to use
I also build mine and handlay mine in N scale.
Sorry never used any calcul to obtain frog angle , but just a drawing of track which I need to fit in my asked scheme and place.
I just keep two rules in mind, space between track, a minimum radius as a general rule for all the design of my track
The layout of the track is designed by a yardstick on the future roadbed, the yardstick is bend to follow my asking scheme of track in a curve, a second one design the diverging route and I bend it to fit and follow my future diverging route, in any case I try to use the biggest radius possible, easement are natural
It's a extremly flowing design track, the frog is build on the place of the start of the diverging route, the rest of the turnout is build up around the frog.
Yes this need some little adjustment and the lenght of the turnout is done by using the famous ratio between frog angle and lenght, but in fact I don't care a lot about it, no matter if the frog is 6, 7, 8 or other angle and the lenght is not really related to the ratio, it just need to follow my designed diverged route and I buy the lenght to have a quiet large turnout in curve which in any case as better running qualities.
This link is Dave Stewart famous O scale layout, all the track is handlaid no flex anywhere, but no calculs only yardstick design methods and track laid to follow the draw line from the yardstick design.
www.aorailroad.com
They have build more than 200 turnouts on the layout this way including extremly intricate pieces of track mixing turnouts, crossing and double slip in one piece; just from the yardstick drawn, no more, no less, and no any angle calculs
Further, the same yardstick avoid to follow any geometry fixed by a commercial turnout, they connect any piece of track again naturaly by bending the stick and with a incredebly flowing track design.
Marc, I agree it is really not necessary to fiqure frog angle for flowing special track work when hand laying.
There are lots of different methods for hand laying, and making frogs for standard turnouts with a standard jig does require a choice of size in advance.
I lost interest in building hand layed track for the entire layout many years ago when better commercial track became available.
I now only build special pieces when needed. I have learned ways to modify commerical turnouts in many cases to achieve the smooth flow of hand layed track, even in some unusual situations.
I model in HO, and would not even consider N scale with commercial track, so my hat is off to you with hand layed N scale.
I think the 60 inch outside radius of the Peco turnout would be useful only at the end of a curve or possibly at the beginning where it could act as a sort of spiral easement connected to a tangent track.
Its difficult to cut it into the middle of a curve with that broad of a radius..
Marc_MagnusSorry never used any calcul to obtain frog angle , but just a drawing of track which I need to fit in my asked scheme and place.
for me, it was't the frog #/angle but the frog position. I couldn't figure out how the commercial turnouts were made with the frog was so close to the points.
some math finally helped me figure out, but I wish i had figured it out sooner.
of course someone can figure this out with yarsticks and drawings instead of using geometry on a laptop. such a precise approach isn't needed to design an entire layout, but can help in the tight spots
gregc Marc_Magnus Sorry never used any calcul to obtain frog angle , but just a drawing of track which I need to fit in my asked scheme and place. for me, it was't the frog #/angle but the frog position. I couldn't figure out how the commercial turnouts were made with the frog was so close to the points. some math finally helped me figure out, but I wish i had figured it out sooner. of course someone can figure this out with yarsticks and drawings instead of using geometry on a laptop. such a precise approach isn't needed to design an entire layout, but can help in the tight spots
Marc_Magnus Sorry never used any calcul to obtain frog angle , but just a drawing of track which I need to fit in my asked scheme and place.
I completely agree with you Greg.
I just try to show things could be used in a simple way.
I make a lot of calcul for my job in metalic structure.
But It seems to me this is not necessary four our little trains, and just the question of this thread seems to me to show people are quickly lost with small problems.
So I simply try to approach this problem with the simpliest way which is affordable for everybody and which can in a certain mesure, allow everybody to go over these problems without the need of calculations or big reflexion about it.
But in a other way I admire the sketches and the mathematics study you have done to show how these radius of manufactured turnouts are not the one announced and the combination of the two radius is somewhat obscure
I just overlayed the Atlas code 83 curved turnout over actual curves, I have a 30, 33.5, and 36 on my layout and layed it over all three. The outside arc is 30" on the money, I could cut and drop it right in to the 30" curve perfectly. I don't have a comparison curve for the inside arc.
I have several Atlas curved code 83 on my layout, and happen to have a bunch of Ribbon Rail curved guages. So out of curiosity I decided to see what they told me.
Because of the trackage in the middle of the rail it's not possible to insert the guages in the normal manner, so I carefully placed the guages right on the top of the rail and looked for the one in each case that precisely follows the rail evenly around the curve.
There is only one in each case that tracks absolutley true with the rail curvature using this method.
Outer curve: 30"
Inner curve: 22"
It appears to me that the answer to the OP's question is yes, they are exactly what Atlas says they are.
Deane