Anyone know how wide one needs to do a 30 radius. What is the largest radius turn one can do on a 4by8ft sheet of plywood' that is on the 4ft wide side. Is their a scale that tell how wide each radius needs. Thanks
fender777Anyone know how wide one needs to do a 30 radius.
66" will allow 3" from the edge of the benchwork to the track centerline. This is usually considered the minimum to keep trains off the floor. More is better.
fender777What is the largest radius turn one can do on a 4by8ft sheet of plywood' that is on the 4ft wide side.
The 22" radius sectional track curve was invented for just this application. It does put the track dangerously close to the edge though.
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Multiply the radius by two. That will get you the diameter of you circler at the center line of the track. Add about an inch and you will have the outside diameter of the circle of track. You can use 22" radius track on a 4 x 8 sheet of plywood. Most layouts that have larger radius are around the wall layouts.
Radius and diameter in model railroading
Curve radius rule-of-thumb for various equipment
Layout Design GalleryLayout Design Special Interest Group
In planning your layout, if getting the track close to the layout edge, consider a rollover (off the table) barrier.
As an example, my small layout has track center just 2-1/2" from the edge, but I have a masonite fascia that extends down about 1', but also extends 1-1/4" upward past the table surface. If a loco rolled off the track and towards the edge, the fascia edge hopefully would stop it from diving to the floor.
Paul
Modeling HO with a transition era UP bent
peahrens As an example, my small layout has track center just 2-1/2" from the edge, but I have a masonite fascia that extends down about 1', but also extends 1-1/4" upward past the table surface. If a loco rolled off the track and towards the edge, the fascia edge hopefully would stop it from diving to the floor.
I do the same thing, but my fascia only extends about 1/4" or so above the edge. Not much protection, but some. I run a small fillet of lightweight plaster along the triangular ridge and form up a trackside drainage swale.
Robert
LINK to SNSR Blog
This is roughly a 33" radius, with no restraining wall.
The slope of the trackside bank is designed variably, so that no matter at which point on the grade a car or locomotive derails, it will execute a 360° roll, allowing it to land perfectly on its wheels when it hits the floor.The drop to the floor varies from 49" to 55".
Wayne
Eek, no guard rails makes me nervous with that drop! Of course, it's your trains.
Rio Grande. The Action Road - Focus 1977-1983
A few comments from the peanut gallery.
If you want spiral transitions into your curves (See John Armstrong's Coefficient of Lurch sidebar) add an inch to Cuyama's width diagram.
Doctor Wayne is demonstrating what you can get away with if your tracklaying is absolutely bulletproof.
For those of us less talented, it is possible to incorporate scenery elements that act as disaster preventers. A three-cable right-of-way fence, #24 wire soldered to straight nail fenceposts, will keep ANYTHING on the right-of-way. Likewise foliage that incorporates structural elements (screen wire, solid 'trunks,') can be planted in the drainage below a bridge to make a gentle catch out of a potential springboard bounce to oblivion. All without having the fascia intrude into the model space.
For a situation like Doctor Wayne's, the JNR thought highly of guard rails - and not just on curves. I think that idea is one I'll emulate.
Chuck (Modeling Central Japan in September, 1964)
You can also make a "wall" out of clear acrylic.
Ed
I went Ed's way also, with a plexiglass "wall" along the edge of the layout. Not only does it keep the rolling stock from disaster, it also protects my scenery from the arms and elbows of guests and grandkids!
On my 4x6 I have a spot where the tie ends are at the edge of the layout. Jeff's words are just about what I was going to say before I read his. Mine goes several inches above the layout surface.
Good luck,
Richard
On the old SIW I put a stack of containers (actually a picture glued to hard board and cut to shape to act as a back stop if a train derailed if you looked at eye level as an n a picture you would not know the difference in that one area.
Joe Staten Island West