atlas #5 switch length

If you're doing some serious layout planning, I'd suggest investing in RR-Track so you can see exactly how things come together early on in the planning stages.

But to answer your question at a high level... the Atlas #5 turnout is 20" in length, and there's really no "overlap" in length when making a cross-over... so you need 40" to create a #5 cross-over that yields the 4.5" track spacing.  You can essentially add small fitter pieces to create wider parallel track spacing, but then you're definitely looking at needing flex track for (at least one of the) parallel curves.  The beauty of the 4.5" track spacing is it matches up nicely with the track-spacing of Atlas-O's double-track bridge as well as the radii of their stock curve pieces.

You save substantial space if using O72 switches cut for the cross-over (only requires approx. 24"), but then you're dealing with a potentially troublesome S-curve on the cross-over which is not very prototypical (even when cutting the curved legs of the turnout somewhat).  If you can afford the space, I'd definitely recommend using #'d turnouts for the cross-overs rather than O72 turnouts.  Your trains will appreciate it, and the operations will be more reliable (at all speeds) and look much more prototypical.

David

Thanks for the reply, the problem with 4.5 spacing is it will not work with challengers and scale pass cars UP fan here so I am going 5.5(should do 6). I am thinking of doing one 072 inner loop, 090 081 072 072 081 090 outer loop, or whatever it takes to get to 5.5-6 on the outer. I have 16 feet for the crossover for 3 mains so that should be no problem.

I stay with the 4.5 spacing on straights and very brood curves.    On tighter curves I use flex track and just increase the spacing.   Doesn't seem like a big deal to me.   There's no reason I can see to have your straight track areas and curve track areas match in spacing.

Atlas flex track does not work well under 108" radius, I have some.  I also think flexing into a curve from 4.5-5.5 looks dumb, one track yes but 2 or 3 just leave the whole thing at 5.5.

"Atlas flex track does not work well under 108" radius, I have some."

If you meant Dia., not true. I've flexed 081, 090 and 099 with ease.(with also the help of a 4.5" custom made spacing jig.) There is a science in bending flextrack.

1-Start by sliding all the rails out of the track section. (do this for 2 sections) The goal here is to overlap the rails onto the next section of ties.

2-You will have to pre-bend the rails slightly by grabing both ends of the rail. The reason for this is to relieve the resistance.(do not bend it too much because it will be difficult to slide back through the ties) Remember, we're going to be over lapping to the next section of ties.

3-Once you have bent the 1st 3 rails, slide them back onto the section only half way through.(the less you have bent the rail, the easier it will slide through)

4-Take the next section of the ties and slide them through the rails and snap the ties sections together.(you should have 3 rails over lapping on both tie sections)

5-Once you have your roadbed into place, fasten this section in using #4x-3/4" philips head screws (both lowes and HD have these.) Once you have done, you will repeat this throughout the radius.

To install the rail connections: You will need to purchase a bag of the Atlas Tie Ends. As you do your radius, you will be cutting up and modifying the Tie sections.( you might have to call me on this) When connecting the rails, some of the ends of the rails might eventually end up on top of the fish plates. Take an exacto or utility knife and slice those fish plates off the ties. Slide the track connectors all the way in and when you butt up the next rail, slide the connectors to connect both rails. You will now have the flexibility to make your radii. Keep slightly bending the rails and fastening as you go along.

Contact me off the forum if you need further assistance. Hope this helps.

Cesar