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Ok  when one is talking about switch tracks and  they say it is a   # 6.    Does it mean that the  larger the number  the less the curve of the switch? 

Or  the  higher the number the  tighter the curve of the switch?  

Any one got a chart to covert   numbers to  diamaters?


When it comes to Scale I have burned into my brain    THE SMALLER THE NUMBER THE LARGER THE OBJECT.:D
 

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Actually, I think numbered switches don't have a "radius."

Radius switches diverge from the straight through track on a curve that has a radius (i.e. Aristo Wide Radius switch is a 10' diameter - 5' radius curve.)

Numbered switches diverge from the switch at an angle. The number of the switch is the ratio of the number of units the diverging track goes forward for a one unit distance from the through track. In other words a number 4 switch would have a diverging track that separated from the through track by 1 inch for every four inches of length on the diverging track. On a number 8 switch, the diverging track would be 8 inches long before it had diverged 1 inch.
 

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Posted By CCSII on 03/02/2008 8:51 PM

Numbered switches diverge from the switch at an angle. The number of the switch is the ratio of the number of units the diverging track goes forward for a one unit distance from the through track. In other words a number 4 switch would have a diverging track that separated from the through track by 1 inch for every four inches of length on the diverging track. On a number 8 switch, the diverging track would be 8 inches long before it had diverged 1 inch.
Finally, an explanation of the numbers that makes sense. Thanks.
 

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For numbered switches, there is no right angle involved. The number refers to what the mathematicians call an Isosceles triangle, a triangle with two equal sides. For switches, the two sides (of the triangle) are 4 or some number and the base is always 1. If you measure the '1' straight up or down to the diverging rail, you're making the number of the switch larger than you had wanted.

To belabor the point, a Number 1 switch forms an equilateral triangle, all sides the same length with a frog angle of 60 degrees. But if you measure out 1 distance and then measure straight up the same distance, that will form a 45 degree right triangle; the frog will be 45 degrees and would be a Number 1.4 switch.

Art
 

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The right angle is indeed close enough as CCSII says, especially if the numbers are above 5. But there is no need for this approximation as all you need to do is strike an arc of a unit's length at the end of the 4 or 6 or whatever unit length you're using, and then strike a line from where the point of the frog will be to where it is tangent to the arc (not intersecting but just 'kissing' the arc). Simple and accurate (but hardly necessary a-tall).

Art
 
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