here we go then. figure 8 within oval using the Snap Switches (22.5 degree, 10.5 inch) and 22 inch curves otherwise. 30 degree crossing
When I hear the iron horse make the hills echo with his snort like thunder, shaking the earth with his feet, and breathing fire and smoke from his nostrils, it seems as if the earth had got a race now worthy to inhabit it.
-- Henry David Thoreau
Don't forget, this for a figure 8 within an oval, likely further restricting the figure eight. And, to get a 90 degree crossing as part of the figure eight, you will likely need a surface larger than 4' x 8' on an HO scale layout.
Rich
Alton Junction
a 22" curve fits fine with a 45 degree crossover:
and of course, by manipulating it with partial curves, you can probably get any angle to fit
Great effort, greg.
That's what I was referring to when I mentioned "operationally possible".
Can you lay out such a pattern on a 4' x 8' surface and keep trains from derailing on too tight curves.
the following attempts to show the crossing angle required for a figure-8 on a 4x8' layout with two possible curve radii. The assumption is a larger radius oval outside of figure-8, not that this was originally explained by the OP.
The 22" radius curves are shown in red and 18" curves in orange. The 22" curves are centered 24" from the center of the board. The 18" curves are centered 26" from the center of the board. Two possible crossing angles are shown, 90 (green) and 60 (blue) degree.
It's seems clear that a 90 degree crossing could work with 18" radius curves but not 22" curves. A 60 degree crossing would not work for either curve radius, much less a 30 degree crossing.
greg - Philadelphia & Reading / Reading
Meanwhile, so far, no one has answered the OP's one and only question, what would be better to use, a 90 or 30 degree crossing?
It seems to me that a 90 degree crossing would not be operationally possible on a 4'x 8' layout with a figure eight inside an oval. The layout surface would require more width and more length.
ScrewySqrl that does depend on how you do your oval-and-8. Atlas did several that linked the oval and 8 by sharing a 180-degree curve, so it didn't have reversing sections
that does depend on how you do your oval-and-8. Atlas did several that linked the oval and 8 by sharing a 180-degree curve, so it didn't have reversing sections
It's possible, but that is not what the Original Poster is describing.
Edit: At least, I don't think that is what the OP is describing.
Layout Design GalleryLayout Design Special Interest Group
By the way, the oval-plus-figure-8 arrangement creates reversing loops, which require special wiring. This can be managed in traditional DC with additional wiring, track gaps, and toggle switches, or in DCC with additional feeders, track gaps, and auto-reversing modules. Just something to be aware of as you go forward.
It will probably be helpful to folks if you specify the maker and type of track you are using. Looking at Atlas Code 83, for example, it likely won't be possible to build the arrangement that you would like with #6 turnouts on a 4'X8' sheet. What radius curves are you using?
You might be able to make it fit on a 4X8 with Atlas “Snap-Switches”. These are much sharper than a #6, but curve away from the straight route more sharply.
Of course, there’s no requirement to confine yourself to a 4X8, either. In the same floor space as a 4X8 and its aisles, many other interesting layouts may be built.
Best of luck with your layout.
This link may help you.
http://www.atlasrr.com/Code100web/index.htm
Steve
My question is what track is needed to complete the figure eight part of my HO layout. I have a 4 x 8 HO layout. It is an oval with a figure eight in the middle. I completed the oval with fourteen 22-degree turns and four number six switch tracks. I also have three nine-inch pieces of straight track on either side. I could add a three-inch piece of track on each side if needed. In addition, what would be better to use, a 90 or 30 degree crossing.