E-Z turnout questions.

[ben_not_benny]

If I want to bring the diverging leg on the #5 turnout back so that it would be parallel with the straight leg, what degree of curve do I have to use? What about the #6 turnout? Also, which straight lengths do I have to use to match the lengths of the two tracks? (i.e. they end at the same point.)

I plan to build a HO layout soon with E-Z track and I need some information on what to purchase to get me started. Also, if anyone has dimensions of #5 and #6 (DCC) turnouts, that would also be greatly appreciated. Thanks!

[the Bach-man]

Dear Ben,
As the divergent leg of  numbered turnout is straight, there is no set radius to achieve a parallel track. Rather, you will have to trim a curved section with a track saw. Only the standard turnout has a curved side, which is 18" radius.
Have fun!
the Bach-man

[Yampa Bob]

Ben
Refer to this thread, read all the posts for the answers to your questions.

http://www.bachmanntrains.com/home-usa/board/index.php/topic,4682.0.html

For the #5 turnout, Bachmann does make a piece to return parallel, although the track spacing will be a bit wide.  For a narrower spacing, then you would have to cut a piece of 18" radius at exactly 12 degrees divergence angle.

Since a 1/2 - 18" piece has a divergence angle of  15 degrees, trim off a bit to get it exactly 12 degrees. 

For the #6 turnout, a 1/3 - 18" piece will be parallel within 1/2 degree.


Bob

[Joe Satnik]

Dear All,

John Armstrong lists a #5 turnout as having a 11.4 degree frog angle.  Assuming that the frog angle continues without turning to the divergent end of the turnout, you would need exactly an 11.4 degree turn in the opposite direction for a parallel siding. 

The closest is a half 22"R curve, Item #44532 (4 per card) which is 11.5 degrees. 

If you want a wider parallel spacing, a 12 degree 33.25"R curve, Item #44509, (4 per card) will work, but with 0.6 degrees of error, which is probably imperceptible.

A #6 turnout has a 9.5 degree frog angle.  As Bob pointed out above, the 1/3 18"R curve has 10 degrees, which is within 1/2 degree.  The problem is that you reduce the minimum radius for the turnout ("Radius of the Closure Rail") from 43"R down to 18"R. 

It wouldn't hurt if Bachmann were to release a 43 or so inch Radius - 9 degree "half" curve.  (Wish List)

Hope this helps.

Joe Satnik       

[Yampa Bob]

If you examine a #5 turnout, you will see that the diverging rails make a slight turn before the frog.  Even though the track continues straight after the frog, the total divergent angle at the end of the turnout is 12 degrees. 

As stated in the thread I linked to, several members have successfully returned the tracks to parallel by using the 33.25" radius, either a single 12 degree piece, or 2 of the 6 degree pieces.

Therefore total divergent angle is not the same as frog angle.  The slight curve before the frog is the "transition" area. All turnouts have a transition curve before the frog.

Someone once stated that the standard remote turnout frog has no angle.  Of course it has an angle and can be measured geometrically.  Manufacturers do not assign a frog "number" to the standard constant radius turnout, but a number can be roughly assigned.   

In the Ogden Utah freight yard, the turnouts are so sharp they could be classified as a Number 3 or Number 2.  The smaller the number, the larger the divergent angle.

In their track catalog, Atlas specs their turnouts in terms of total divergent angle, not frog angle. It would be helpful if Bachmann included the same specs on their turnouts.

[Jim Banner]

If you examine a #5 turnout, you will see that the diverging rails make a slight turn before the frog.  Even though the track continues straight after the frog, the total divergent angle at the end of the turnout is 12 degrees.

What the rails do before the frog is irrelevant.  The angle of the frog can be expressed either as a frog number or in degrees, and there is a definite trigonometric relationship between the two.  An exact #5 frog has a angle of 11.478 degrees, or 11.5 degrees for all practical purposes.  A frog with an exact 12 degree angle would be a #4.783 frog.

John Armstrong may have used the average of the arcsin of the frog number and the arctan of the frog number which gives a close estimate and was an easy short cut in the days before scientific calculators.  Or he may have used a slide rule to do the calculation.  But with scientific calculators readily available, we can do an exact calculation using

   frog angle = 2 x arcsin ( .5 / frog number)

The question then becomes "how much angular error can we afford to have in the joints of our trackwork?"  In the average layout using sectional track, one-half or even one degree error is a minor kink.  By comparison, a #8 turnout with 3" points, a .050" flangeway and a .050 railhead typically has a "kink" of about 2 degrees where the diverging route takes off from the straight through route.  (Shorter turnouts generally have some curvature in the points to reduce this kink.)