Hey I’ve been using Atlas’ track plan softwarefor a few days now , and its pretty good, except for one recurring problem with the turnouts. I cannot even build a circle with a spur in any radius, because the turnout never seems to fit properly and ends up at an odd angle.
Is there something I’m missing or is atlas track really like this? if it helps its in N scale, code 80 track.
thanks for any help in advance.
Prototype turnouts are just two straight tracks joined. There is no curvature to a prototype turnout. Toy train (Lionel for example) turnouts have a curved diverging branch and are shapped like a standard curve track superemposed upon a standard straight track. This allows you to replace a standard curve piece with a turnout without affecting the curve. The prototype turnouts will not allow this, as track layout program is informing you.
In HO, Atlas makes both sorts of turnouts, the prototype (Mark IV) and the toy train (Snaptrack), but in N they only offer the prototype turnouts. The prototype turnout acts sort of like a piece of curved track but of larger radius than the standard curved pieces. You may have to cut a short piece of curved track to make a curve do a right angle, or even close upon itself. Or use some flex track.
“Track Planning for realistic Operation” by John Armstrong has a better discussion of turnout geometry than I can do here (or anywhere else for that matter). Good read, lots of good ideas.
Good luck
I concur, I just picked this up, and it’s an excellent resource. I’m glad I picked it up BEFORE finalizing my plans on my big layout.
I don’t know anything about their N-scale turnouts, but Atlas HO-scale “snap-switches” look like a 9-inch straight section overlayed by a 6-inch curved section. The curve starts about an inch and a half down the straight from the end. The curve matches their 18-inch radius sections, but it’s only 6 inches long. So, instead of the 30-degree arc of a standard 9-inch piece of 18-inch radius section curved track, the arc is only 20 degrees. For that reason, Atlas snap-switches typically come with a 3-inch curved section, as a separate piece of track, to allow you to complete your circles properly.
MrB:
There’s also an ~1.5" straight section at the point end, leading into the curve, so the Snap-Switches can’t be dropped directly into a curve (unless you pull a Westcott and curve them to match it). What is very odd about newer SS’s compared to old is that the 1/3-curve section is distinctly shorter in length now, by about 1/4" or more IIRC.
If you’re trying to connect the turnout with another turnout creating a “circle”, connect a piece of flextrack to the diverging routes of each turnout with a length of flextrack. Then you can use the flextrack shaping tool to shape the piece of track.
Dito^
Yep. The “Snapswitch” turnout in HO is just like that, shaped like a curved track set on top of a straight track. In HO, Atlas also makes “Mark IV” turnouts with no curve to them whatever. In N, the Atlas web site only shows ONE type of turnout, the all straight prototype style.
Where did you go in NH to find the Armstrong book? Hobby shops are a little thin on the ground up here north of Franconia Notch. I have to drive an hour over to Hartmann’s in Intervale to find anything railroad related. Is there some other place I have been missing?
Ok I think I understand, I would have to use flex track in the software program, but there is a seperate piece with the actual turnouts that remedy this problem?
Did you try 19" radius with the standard turnouts? That should have worked.
Atlas’ low end switches are designed to fit into circle. In HO they are designated as ‘Snap swithes’. In N gage they are called ‘Standard’.
http://www.atlasrr.com/Images/Track/Trackphotos/2700.GIF
I don’t know the diameter of the circle as Atlast doesn’t tell us, so ask them.
Kato has more products in N, but their switches are numbered - which follows north American practice (non circles); and many European track makers still make their switches to form a circle, (Tillig. Rocco,Peco) but it is in millimeters. Good hunting.
I concur. I have a funky little 2’ x 4’ layout built about 8 years ago with Atlas code 80 track that uses these standard turnouts, and a 19" radius curve can be substituted exactly for a standard turnout (along the diverging route, of course). Jamie
I ordered a copy from Barnes and Noble. It wasn’t in stock, but I bought it through one of their retail stores, so I paid no shipping. One phone call, and it was there in a few days. Check Amazon, too. (I had a gift card, so B&N was my choice.)
Yes. A 1/3 18" radius curved track segment connected to the diverging route of the turnout will equal 1 whole piece of 18" radius curved track. (note the extra piece of track in the following link.)
http://www.ehobbies.com/atl543.html
This only pertains to their “snap” switches. NOT their numbered switches.(#4, #6, #8)
ok, thanks everyone.
An NMRA-standard turnout has two related radii for the diverging route:
If your curve is at or close to the minimum required by your rolling stock, cutting out an arc and replacing it with a turnout of standard design has the same result as kinking the flex track.
Trimming a commercial turnout to eliminate the straight track ahead of the points and behind the frog will reduce, but not completely eliminate, the problem. It reduces the replacement radius, but not the effective radius.
One answer (mine) is to hand-lay turnouts. It isn’t the best solution for someone who’s never done it. It does allow insertion of an appropriate turnout ANYWHERE. For a turnout on a curve, the straight route actually assumes the shape of a spiral easement through the points, closure rails and frog.
Chuck (modeling Central Japan in September, 1964)