The New #4 HO EZ-Track Turnout is.....

[Joe Satnik]

Dear All,

The New #4 HO EZ-Track Turnout is.....

Actually a #4.  Within 1% error.  (Atlas' #4 is actually a #4.5)     

That is, if you can:

1.) Believe the photo in the on-line catalog is of the real product,

2.) Trust my measurements (ruler-on-monitor-screen) and calculations

3.) Trust that vertical and horizontal lengths shown on my screen are in the proper proportion (i.e., not distorted).

The small error was a surprise to me, as my measurements were pretty crude. 

The only real way to find out is to have the real turnout in hand and measure it, as Bachmann has never officially released even the lengths of the main routes of their turnouts to the public.  (Highly guarded corporate secrets?)

The main concern to the modeler, though, is which curve will bring the divergent route back to parallel with the main. 

#4 turnouts have a departure angle of 14.25 degrees. (Armstrong)

The closest curve is the 18"R half curve, which is 15 degrees. 

Armstrong's charts also list the "Radius of the Closure Rail" RCR as 15"R.  This means that the (slightly larger) 18"R curve would be a good match to the #4 turnout.  (The RCR tells us the tightest radius a loco or car will experience going along the divergent route.) 

Further screen measurements/calculations put the track center spacing between the main and the parallel siding near 2-1/3", which would work just fine.  (= 17 scale feet).

Hope this helps. 

Sincerely,

Joe Satnik     

[Terry Toenges]

Joe - You never cease to amaze me with your model railroad math.

[pdlethbridge]

He and Jim Banner give me headaches

[Jim Banner]

PD WARNING - headache material!!!

Joe, here is a partial explanation of a common error in measuring turnout numbers - heel length vs. theoretical heel length.  But 1%.  I would be happy if I could come up with numbers within one percent!

http://www.harmersteel.com/catalog/frogs-switches-turnouts/frogs/

The whole website makes for interesting reading but keep in mind this is 12" to the foot stuff.

Jim

[Joe Satnik]

Dear Jim,

I straight-edged down the flange side of the frog rails to a theoretical point of intersection, as the details of the frog were lost in the muddy pixels.

Joe Satnik   

[Woody Elmore]

I thought Muddy Pixels was a blues singer from New Orleans.