Well, I spent some time in the dungeon and did a little gerrymandering and I can use the new #4's in place of the 3 old Snap Switches that I has laid out. Since I am going to use Flex track in between I can make up the difference with it. All I have to do is add a little more roadbed in small areas alongside the switch after it is repositioned ro where the track center aligns with the roadbed center.
I had one turn out that I was worried about because of its placement, but when I turned it over lo and behold it was a #4 to begin with!
Robert H. Shilling II
At least back to 1971 when I got started Atlas snap switches have been 18' curved diverging route with the added piece making them equal to a 18" curve section. Atlas #4's have been 4.5's at least as far back as when John Armstrong wrote Track Planning for Realistic Operation (some time in the 60's) in which he specifically cited the Atlas #4 as really being #4.5.
A true #4, that follows NMRA RP12 has, in HO, a short 15" curve which can be a problem for some steam locomotives that otherwise could get around 18" or 22" - the two standard curve sizes for Atlas sectional track back then. The Atlas #4 solves that problem. ( as a side note Fast Tracks now makes jigs for 4.5 turnouts )
I, also, have found it useful in track planning to mock up track arrangements during the design phase. But you should use the same ones for that, that you'll use when you build the layout. Especially with the smaller turnouts, there are a lot of differences.
Enjoy
Paul
Atlas SNap Switches have a curved frog, and are 18" radius to match up with the 18" radius snap-track., They recently came out with a 22" radius SNap-Switch.
Custom-Line turnouts are numbered frogs. The #4 has really been a #4.5 for MANY MANY years, it's nto a new thing. The #6 is really a #6.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I have found the Atlas snaps to be configured for 18" radius. As I recall there is even a small section of 18" radius included to make the turnout blend with other 18" radius curves from Atlas. Nickel silver or brass I have found to be the same as far as the Snap switches go. The 4 is significantly different than Snap switches. I replaced my snaps with 4s wherever I could as the equipment likes them a lot better. And replaced 4s with 6s and now replacing the 6s with the new 8s. Sometimes a Peco 4 can be more easily fit in. You can cut the 4 down also.
I've got about 10 brass Snaps that I am not sure what to do with. The nickel silver stays clean a lot longer
Richard
I am switching to nickel silver track. I really hated the stuff when it came out (too shiney), but that is about all there is now. I guess I can use the new stuff by repositioning the turnouts to align with the already laid roadbed and then add some cork in the area around the new turnout.
If I would have known they changed the turn outs over the years i would have bought new track before I even paid out my track plan.
Since someone will eventually suggest this, so I'll go ahead and be the one...brass track was generally considered "obsolete" by about 1975-80. I'd try using nickel silver on your new layout. If you really need the sharp no.4 turnouts, try Walthers code 83 line of track products. Or if you're definite on using Atlas, try their code 83 nickel silver line. In the long run your layout will be much easier to maintain and run.
The new Atlas #4 turnouts were tweaked a bit higher in the frog number because they were so limiting as true #4's. They must have gotten some complaints from people with tight track curves and found they didn't work so well....dunno the history...but they are now really #4.5's which makes enough of a difference that they are more usable. Unfortunately, you are one that won't find them that way.
I believe the older curved divergent route snap switches are #4's. I think you can still get them. But if the new #4's don't work, I doubt that going to an even higher frog number will be your solution?
Crandell
When I laid out my track to configure what I wanted for a route I used the old brass stuff I have had for years. Now I have the cork roadbed down and am ready to start laying track. However, I bought a new Atlas #4 right handed turn out which is nickel silver. When I placed it where one of my old brass turn outs was at it doesn't match up. The old turn out says that it is an Atlas Snap switch A and there is no number on it. Apparently an A is not a #4. Any idea what the new Atlas replacement for this would be? Is there a #3 or do I go up to #5?