I am trying to make an outside loop with 22 deg curves. I will use all atlas track code 83.
Can some one tell me what the best turnout to use with 22 deg. I know the #6 with the 1/3 18deg matches well with standard 18deg curve.
Any help?
I assume you mean 18" radius and 22" radius curves. Model railroad curves are described by their radius, measured to the center of the track. With an 18" radius curve, you can form a 36" diameter circle - the diameter is twice the radius. A full 18" radius curve section has an arc of 30 degrees; the 1/3 18" radius curve has an arc of 10 degrees.
Unlike 3 rail track like Lionel, no turnouts will drop in as an exact replacement for a full curve piece. Both the Altas #4 and #6 turnouts have straight and curved sections in the "curved" leg. In particular, they are straight where the rails cross, called the frog. The #4 has sharper curved sections - about 22" radius - than the #6. The angle between the curved and straight path is 12.5 degrees on the #4 and 10 degrees on the #6.
The easiest ways to make loops using fixed radius track is to lay it out full size on a table, or use the free Atlas RTS software (free download) to set it up on the computer.
Another alternative is to use flexible track instead of the fixed radius sectional track. You bend the track to the radius you want, and cut off the extra length of the inside rail. With flexible track, you can get much smoother curves, especially when combined with turnouts, for a little extra effort.
my thoughts, your choices
Fred W
jlugar wrote: I am trying to make an outside loop with 22 deg curves. I will use all atlas track code 83.Can some one tell me what the best turnout to use with 22 deg. I know the #6 with the 1/3 18deg matches well with standard 18deg curve. Any help?
jl:
The switches you seem to be referring to sound like Snap-Switches, which aren't no. 6. They are radial-type, with an 18" radius included. Even these, when using the 1/3 curve included, don't replace a stock 30-degree curved section; there is a 1 1/2" straight at the point end. Linn Westcott was known to slice the ties underneath and curve that point end to fit a curve, and apparently it worked well. I have not tried this yet. YMMV.
Numbered switches have straight frogs and diverging section. The ratio of length to divergence is the frog number. There is a curve, of course, to join the straight and diverging tracks. The included curve of an Atlas no. 4 (which is a 4 1/2) is around 22" R, so this should handle any equipment your curves will. It will not be a drop-in replacement. The only thing I can think of that would drop in is a curved track switch. I think Peco makes some with a 22" R on one leg.
There was an earlier thread specifically about Walthers/Shinohara turnouts to which I posted this:
"To recheck my curved turnout sizes (Walthers/Shinohara Code 83), I built a homemade beam compass, laid-out arcs and overlaid the turnouts. The results are:
• #6/#6.5: 24/18 (frog# depends on whether you believe the box label or the imprint on the turnout!)
• #7: 28/22
• #7.5: 32/26
• #8: 36/30
I also checked a #4 Code 70: with a 22" radius for the closure rail, it must actually be a #4.5.
The inside radii are not what Walthers posts nor are they as imprinted on the underside of the turnouts!"
Dante-Thanks for reposting that!I was looking for that info the other day.
If you don't mind a little challenge, Central Valley makes curvable turnout kits that you can build to what ever radius you need.http://www.cvmw.com/cvtswitch/index.htm
Model Power used to distribute a Rocco code 100 curved turnout that had an inside radius of 18" and an outside of 22". They are hard to come by these days, but occasionally I see them pop up on ebay. One caution...they made them in brass and nickle, and I doubt you want the brass. Some of the ebay auctions I've seen are not clear on which they are.
Reality...an interesting concept with no successful applications, that should always be accompanied by a "Do not try this at home" warning.
Hundreds of years from now, it will not matter what my bank account was, the sort of house I lived in, or the kind of car I drove...But the world may be different because I did something so bafflingly crazy that my ruins become a tourist attraction.
"Oooh...ahhhh...that's how this all starts...but then there's running...and screaming..."
jlugar wrote:I am trying to make an outside loop with 22 deg curves. I will use all atlas track code 83.Can some one tell me what the best turnout to use with 22 deg. I know the #6 with the 1/3 18deg matches well with standard 18deg curve. Any help?
Don't know about Atlas turnouts. I use Fastracks turnouts which follow MNRA standards and a # 5 NMRA turnout has a 26" closhur rail radius. I have 24" radius curves, the # 5's are fine but of course I only use em on straight sections. If the closhur rail radius is greater than your curve radius's you wont have any problems.
Jules