gregc what are the lead-lengths of the Peco and Atlas? it's the lead-length and radius of the closure rail that determine how well a loco moves thru the turnout 705
what are the lead-lengths of the Peco and Atlas?
it's the lead-length and radius of the closure rail that determine how well a loco moves thru the turnout
705
I don't know which is longer. They are very close. It may also not be straight. It could be a gradual easement from minimum closure rail radius leading into a straight lead length. Nothing says that your blue line has to be constant radius throughout.
Your diagrams show curves intersecting with the tangent route. Our models have straight points that diverge from tangent at a measureable angle. IOW, a "lead length" at the opposite end of the curve...and possible easement of the closure rail into that.
If we build curves by creating and easement from tangent to curve, wouldn't we want to do the same when building a turnout? A longer easement into a radius requires more linear inches of track, and Atlas is fractionally longer from points to frog. The combo of lead lengths, any easements, and angle of divergence explains it, but I could not tell you the exact measurements. Good luck with that.
- Douglas
gregcit's the lead-length and radius of the closure rail that determine how well a loco moves thru the turnout
Because your blue line is constant and tends to depart from tangent at the same angle, what you say would be true.
But since our models have straight points, a sharper departure angle causes the front end of a car (especially a long cars or loco) to noticeably lurch sideways faster...before the truck is even on the closure rail.
I see the difference in performance. Others may not. Its why I prefer the geometry of the Atlas #6.
DoughlessThey are very close.
DoughlessIf we build curves by creating and easement from tangent to curve, wouldn't we want to do the same when building a turnout?
the Catskill Archive - Frogs and Switches page describes prototypical turnout dimensions, including constant turnout radius (table 35)
the reason for prototypical easements are necessary to give trucks time to pivot on curves
Doughless IOW, a "lead length" at the opposite end of the curve
869
greg - Philadelphia & Reading / Reading
crossthedogThe thing I don't love about Walthers and Shinohara is the shallow ties that don't match the rest of my track, which is Atlas flex.
I used the Walthers-Shinohara code 83 turnouts on my 2012 layout and was made aware of the tie height difference here. Some folks just let the rail joiners and ballast handle the way the turnout would tend to float. I added a shim as others suggested, either a piece of 0.015" styrene sheet or a clear coated (to avoid swelling during ballasting) cutout of the W-S turnout box, which happened to be the right thickness.
I believe the background was that the Atlas code 83 flex track (which I also used) had thicker ties to mate veritically with code 100 track. Thus the 0.017" thicker ties on the Atlas code 83 flex than the W-S code 83 turnouts, designed to mate with Walther code 83 track with the thinner ties. Apologies if I have this story wrong or misunderstood.
Paul
Modeling HO with a transition era UP bent
gregc the distance between the points and frog is simply a measurement, not some geometric feature.
the distance between the points and frog is simply a measurement, not some geometric feature.
Rich
Alton Junction
richhotrainWouldn't that distance simply be the length of the closure rail?
gregc richhotrain Wouldn't that distance simply be the length of the closure rail? the straight closure rail
richhotrain Wouldn't that distance simply be the length of the closure rail?
the straight closure rail
Length of Straight Closure Rail:
~ Atlas Custom Line Code 83 #6 turnout - 4.0" (exactly)
~ Peco Code Insulfrog Code 83 #6 turnout - 3.03125" (3 1/32")
are you sure it's only 4" and not closer to 6"
it's the total distance from the tip of the point to the tip of the frog
crossthedog The thing I don't love about Walthers and Shinohara is the shallow ties that don't match the rest of my track, which is Atlas flex. -Matt
The thing I don't love about Walthers and Shinohara is the shallow ties that don't match the rest of my track, which is Atlas flex.
-Matt
I fix the thin tie thickness in Shinohara and Walthers turnouts with a styrene (.020” x .100”) strip added under every 4th tie to bring the rail tops level with the Atlas Code 83 flextrack; per a tip in a MRR article.
Jim
gregc are you sure it's only 4" and not closer to 6" it's the total distance from the tip of the point to the tip of the frog
wrench567 crossthedog wrench567 Shinoharra was mostly code 100 or code 70. I don't recall them having a code 83 line. My Code 83 Shinos must be counterfeits, then. :/ That would explain why I got such a good deal on them. -Matt I stand corrected. I have some code 100 and my industrial lead is code 70. I don't remember seeing a code 83 from them. Pete.
crossthedog wrench567 Shinoharra was mostly code 100 or code 70. I don't recall them having a code 83 line. My Code 83 Shinos must be counterfeits, then. :/ That would explain why I got such a good deal on them. -Matt
wrench567 Shinoharra was mostly code 100 or code 70. I don't recall them having a code 83 line.
My Code 83 Shinos must be counterfeits, then. :/
That would explain why I got such a good deal on them.
I stand corrected. I have some code 100 and my industrial lead is code 70. I don't remember seeing a code 83 from them.
Pete.
rrebellShinohara made code 83 for Walthers.
Shinohara also marketed the Code 83 line under their own name in the familiar brown boxes outside North America.
crossthedogMy Code 83 Shinos must be counterfeits, then.
Nope. They sure look genuine to me.
The code 83 line marketed by Walthers was made by Shinohara and said "Shinohara", not "Walthers" on the back side of the tie strips.
-Kevin
Living the dream.
richhotrainThe straight closure rail on the Atlas turnout is exactly 4.0" in length
thanks
but it's the distance from the frog to the points, not to the hinge. prototypical turnouts don't have hinged closure rails
gregc richhotrain The straight closure rail on the Atlas turnout is exactly 4.0" in length thanks but it's the distance from the frog to the points, not to the hinge. prototypical turnouts don't have hinged closure rails
richhotrain The straight closure rail on the Atlas turnout is exactly 4.0" in length
thanks but it's the distance from the frog to the points, not to the hinge. prototypical turnouts don't have hinged closure rails
greg, you keep upping the ante. How many more measurements can one make? You did say that the length of the straight closure rail was what you were looking for!
one measurement, lead-length. the closure rails include the points.
Tom Bryant_MR I was using Shinohara turnouts years ago. I eventually moved to Fast Tracks. Loved them. I see Shinohara is out of business. So, I would need to purchase all of the Fast Track jigs again. I would welcome others experience with other turnouts in the market. Thanks Tom
I was using Shinohara turnouts years ago. I eventually moved to Fast Tracks. Loved them.
I see Shinohara is out of business. So, I would need to purchase all of the Fast Track jigs again.
I would welcome others experience with other turnouts in the market.
Thanks Tom
Fast tracks sounds great, but it requires TIME. Nice for those who have hobby time. A layout take a lot of time as it is, but for those of us who don't have much hobby time, we have to use good quality modular track. So while some of these solutions sound really wonderful, they aren't possible if you don't have the time to do it. But that doesn't mean someone can't build a well designed and well operating model RR.
Rio Grande. The Action Road - Focus 1977-1983
greg, your drawing was no help because it didn't identify the actual "lead length".
So, I researched the issue and found this link.
http://www.pcrnmra.org/pcr/clinics/Kolm-TurnoutsWhatYouNeedtoKnow-PCR2008-handout.pdf
Here is a drawing from that link with a visual description of the "lead-length". Is this what you are looking for?
isn't that the same drawing i posted at 8:02.
i'm looking for the lead length which it identifies as "lead" being from the point-of-switch to point-of-frog
We have been thru this turnout dimension thing so many times......
The Peco turnout has less track before the points and after the frog on the straight thru route.
The Peco turnout has a slightly shorter length from point tip to frog ( lead length), resulting in a slightly sharper closure rail radius.
The Peco turnout has a curved diverging point rail (even if it looks straight at first glance), the Atlas diverging point rail is straight.
The Atlas point to frog dimension is longer than NMRA RP, the Atlas turnout has a more gradual departure, and thereby a slightly larger substitution radius and closure radius.
If you really need or want to pack them in tighter, the Atlas can be trimmed.....
The frog angles are the same.
Greg, I have already explained to you several times the flaws in your one diagram......
You can't work from the points, you have to work backward from the frog. A shorter point to frog dimension means a sharper closure radius - period. For any given frog angle there is a range of point to frog lengths that will work, longer means larger closure radius - up to the limit of the geometry established by the frog angle.
I've built my own turnouts, without FastTracks, and used every brand on layouts I have built or helped others build.
My choice is still Atlas, electrically and for geometry.
All these differences are VERY small.............
The Peco turnout only makes a more compact crossover by virtue of the shorter lead length and the shorter track length past the points.
The Peco turnout does not make 2" track center diverging routes for yard ladders,, it needs small spacer tracks. That is why the Atlas has the longer straight route, to make 2" center yard leads.
By design, the Atlas turnout discourages placing curves too close to the points or frog, which can often be a source of problems, especially for those who insist on smaller radius curves.
Sheldon
ATLANTIC CENTRALYou can't work from the points, you have to work backward from the frog. A shorter point to frog dimension means a sharper closure radius - period. For any given frog angle there is a range of point to frog lengths that will work, longer means larger closure radius - up to the limit of the geometry established by the frog angle.
Greg,
There are prototype turnouts with and without hinged points.
The nature of the materials suggests that the closure rail will flex right at the spot where it is no longer fastened down to the ties. And if that is a fishplate joint, it will behave much like our model track at a kinked rail joint - that is a defacto hinge.
ATLANTIC CENTRALThere are prototype turnouts with and without hinged points.
riogrande5761Fast tracks sounds great, but it requires TIME. Nice for those who have hobby time. A layout take a lot of time as it is.
I prefer to spend my hobby time not building turnouts.
I do prefer detail painting. That takes time, and I suspect most other modelers prefer to spend time not detail painting.
Do with your time that which you enjoy.
Shinohara turnouts and Atlas track work for me.
SeeYou190 riogrande5761 Fast tracks sounds great, but it requires TIME. Nice for those who have hobby time. A layout take a lot of time as it is. I prefer to spend my hobby time not building turnouts. I do prefer detail painting. That takes time, and I suspect most other modelers prefer to spend time not detail painting. Do with your time that which you enjoy. Shinohara turnouts and Atlas track work for me. -Kevin
riogrande5761 Fast tracks sounds great, but it requires TIME. Nice for those who have hobby time. A layout take a lot of time as it is.
I agree, I am way past the point where I want to scratch build turnouts.
I build the ones I can't buy, and have even learned how to curve Atlas regular turnouts into very large radius curved turnouts.
I have watched others use FastTracks, and the only advantage I see over how I was taught to scratch build them is higher uniformity - you know like just buying them factory made.....
I'm starting a layout with 140 turnouts, I already have nearly all of them I need.
why does it matter?
the actual length of the turnout doesn't determine how well cars or locomotives track through it. as Sheldon has said, "shorter point to frog dimension means a sharper closure radius". a longer lead-length also allows for easements as Douglas mentioned
so two brands of turnouts may both be #6, but one may have problems with longer wheelbase locos, even though its total length is longer while another does not.
So, I don't have any PECO turnouts to look at here, but the nice people at PECO have these nice scale drawings online.
And drafting and engineering are my first skills.......
So here is an Atlas #6 layed on top the PECO drawing which scaled out perfectly based on the scale printed on the the drawing.
As I explained before, the PECO has a shorter lead length and thereby a sharper closure radius - however slight.
The PECO has a lead length of 6", that is frog tip to points. The Atlas measures a whole inch longer at 7".
A product photo of PECO SL-U8362 on the Yankee Dabbler web site also clearly confirms what I said before, the diverging point rail is curved. You can see in my photo the Atlas is clearly straight.
The frog angles match up close enough and the diverging routes end at the same location relative to the rog, so both turnouts will make crossovers with 2" track centers.
You cannot see this in the photo, but if you look carefully thru the Atlas switch laying on the drawing, you can see where the closure rail of the PECO does not exactly line up and its sharper radius offsets it almost an 1/8".
So yes, for the 300th time, the PECO is more compact because it has a sharper closure radius.
If you are using 30" curves and you stuff runs on 30" curves, then this small difference is not of much concern.
If you have larger curves, the Atlas may be more in line with the geometry of your curves.
I can assure you that 80' cars going thru a crossover will look better with the Atlas product. And given the complaints I read on hear about RTR passenger car derailments, I would be inclined to think Atlas would be better for that reason as well.
Once again, the Atlas #6 is longer, more gentle than NMRA RP dimensions. And the Atlas "#4" is really 12.5 degree #4.5.
There is no free lunch in physics or geometry........
Remember, that scaled down from the prototype, a 36" radius curve would be the sharpest curve a Big Boy or an 80' passenger car could squeek around at 10 mph..... and a #6 turmout would likely put both on the ground.
gregc why does it matter? the actual length of the turnout doesn't determine how well cars or locomotives track through it. as Sheldon has said, "shorter point to frog dimension means a sharper closure radius". a longer lead-length also allows for easements as Douglas mentioned so two brands of turnouts may both be #6, but one may have problems with longer wheelbase locos, even though its total length is longer while another does not.
Correct!
In fact nearly all US protoype turnouts with straight frogs have closure rails that are effectively an elliptical curve with and easment into them at the points and out of them at frog.
They are NOT a constant radius.
This is why Greg's drawing of various length turnouts with the same frog angle is not correct - he used constant radius curves and added more straight rail near the frog.
Again, while it cannot be seen in the photo, it is clear the PECO turnout has a sharper "ellipse" for a closure radius. Obviously the rails need to end up in the same places, but mid way in the curve, the PECO bulges out - again, nearly 1/8".
It is that vertex of the ellipse that will be the smallest radius, and the effects of truck swivel and coupler travel come into play.
Now here is some food for thought - the nice people at Atlas designed this geometry for their #6 Custom Line turnout sometime in the 1950's. While the product has been improved, offered now in code 83, had metal frogs added, the geometry has NEVER been changed since the first code 100 plastic tie Custom Line turnout was offered. Pretty smart guys in my book.
I looked uip and printed out the Fast Tracks #6.
6-1/4" lead length......
I will stick with Atlas and build my specials when I need to - without expensive jigs or PC ties.