Jeff But it's a dry heat!
I screwed up #6 thanks
Looks like it is 12.5 degrees, using Atlas #6 turnout. Without cutting anything it looks like the spacing is 3.5" That is HO.
EDIT:
The math I'm doing disagrees with that. It might be htat an Atlas #6 isn't. Hopefully someone who knows wil lhappen by!
nof wrote:The angle should be arctan 1/6 wich is ~9.5 degrees for a # 6 turnout. for a # 7 it will be arctan 1/7 wich is ~8.1 degree. This is the theory at least, hope it is the same in reality.
First Atlas #6 turnouts will result in a 3" track spacing.
Second, the formula for frog number is cot ½ F = 2n where f is the angle and n the frog number. The angle at the frog is bisected, then the number is measured along the bisecting line, not one of the sides of the frog.
Have fun
Correction! 3" spacing is for double crossover using 19° crossing. A single crossover will require 2" spacing.
Vail and Southwestern RR wrote:Looks like it is 12.5 degrees, using Atlas #6 turnout.
Gandy Dancer wrote: Vail and Southwestern RR wrote:Looks like it is 12.5 degrees, using Atlas #6 turnout. I believe that would be the Atlas custom line #4. The Atlas books I have list 10 degrees as the departure angle for their #6. Slightly sharper than a true #6.
Their RTS 7.0 software indicates that the angle is 9.5° for #6 and 12.8° for "#4" (4.5)
exPalaceDog wrote: Gandy Dancer wrote: Vail and Southwestern RR wrote:Looks like it is 12.5 degrees, using Atlas #6 turnout. I believe that would be the Atlas custom line #4. The Atlas books I have list 10 degrees as the departure angle for their #6. Slightly sharper than a true #6.Their RTS 7.0 software indicates that the angle is 9.5° for #6 and 12.8° for "#4" (4.5)Have fun
I think that makes more sense, it is what the math said. I had put together a crossing with XTrkCad, but I don't think I made sure the tracks actually ended up parallel. That's what I get for posting too late at night. And why I questioned myself as soon as I looked at the answer.
Thanks for the right info!
If this is what you're trying to create:
I had to use #4 snap switches along with the 12.5 degree crossing to maintain the 2" spacing. The upper track in the photo ends up being .300" out of parallel because of the frog and crossing angles.
Don Z.
Research; it's not just for geeks.
Cross-overs connecting two close parallel tracks cause nasty "S" curves which cause operational and appearance issues. I'd recommend nothing sharper than #6 turnouts, and if you have cars longer than 60 feet long like full-length passenger cars, I'd go with #8s if possible.
Mark
exPalaceDog wrote: nof wrote:The angle should be arctan 1/6 wich is ~9.5 degrees for a # 6 turnout. for a # 7 it will be arctan 1/7 wich is ~8.1 degree. This is the theory at least, hope it is the same in reality.First Atlas #6 turnouts will result in a 3" track spacing.Second, the formula for frog number is cot ½ F = 2n where f is the angle and n the frog number. The angle at the frog is bisected, then the number is measured along the bisecting line, not one of the sides of the frog.Have funCorrection! 3" spacing is for double crossover using 19° crossing. A single crossover will require 2" spacing.
You and some others are talking about "double cross-overs" where there is a diamond so tracks can "run over" each other connecting two pairs of turnouts opposing each other . A cross-over consists of just two turnouts. Now, I'm not sure what the original poster's intent was, but my earlier comment still stands. You may have to increase the spacing over the nominal 2-inch, but cutting the track parts should get the tracks closer.