Ok, for a #7 switch, you get 1 inch of rise for 7 inches of run. If you arrange left hand switches end to end to form a yard arrangement like the picture below, what is the appropriate track centerline distance between straight track sections . I thought it was 1.25", but apparently not. Can you guys help me with this. I must be missing something... The reason I think I am wrong, is if I draw a 1:7 angled line, my switches will line up, but not without a small once inch or so section of flex between each one.... The track line centers you see in the photo are 1.25" center lines. In the picture above, the alignment looks ok, but when I draw the angle line, and then measure the resulting rise:run it isn't working out to 1:7... Hench I must be fudging with the templates....
Your track layout is correct; you will have to put small straight pieces between the turnouts unless you change the track spacing in the yard. I ran across the same thing in my yard using Peco code 55 no.6 turnouts. OTOH, you could go with closer yard track spacing. IMHO, 1.25 inch is the maximum I would use. I opted to put all my Peco no. 6's back to back (five track ladder) and then place the turnout ladder in the best position to serve all the tracks. Then I made slight curves in the yard track to make them come back to the correct centerline spacing of 1-3/16 inch. It only took about a foot of yard length to achieve the correct track spacing. Experiment and you will see what I mean. It is an interesting problem. The difference in 1/16 inch track spacing will make a difference in how it all goes together. It's nice to have a CAD track program. My Cadrail program showed me there was something wrong with the spacing before I ever bought the track. I didn't figure it all out until I actually put the track in place.
I think you are right on with the line math--the straight route of the turnouts should be centered right along that line. As said above, the track spacing in the yard will determine the space required between the turnouts. Jamie
Hutch: Your rise/sun numbers are correct, but you'll need a section of 2 7/8" track between successive #7 switches to get a 1 1/4" spacing on the yard tracks. Here's a diagram (the 2 7/8" section is shown in blue): The math is as follows: if the yard spacing is 1.25", the horizontal distance between successive frogs is 7*1.25" = 8.75", so the length of ladder track needed between successive frogs is (after Pythagoras) sqrt(1.25^2 + 8.75^2) = 8.84". Since an Atlas #7 has a straight length of 6", you need an additional 2.84" ~ 2 7/8" to get the right spacing. HTH, Gary P.S. This would work pretty well if you don't mind the funky tie cutouts (it would give a spacing of 1.27" in the yard tracks):
The switch "number" refers specifically (and only) to the angle of the frog -- not the overall dimensions of the turnout. This mistake is commonly made. Actual switches from different manufacturers or from different product lines differ from one another in the way the diverging leg is curved, how long it extends, etc. Thus, yard ladders will vary a bit from track brand to track brand, even for switches nominally of the same "number". So you'll need a slightly different amount of track between turnouts, or you may even need to trim the turnout slightly in some cases, to match the particular track-to-track spacing you desire for the yard.
Thank you all for clearing this up for me. Gary, your diagram and math really helped me, I appreciate the time you took to do this. This is the first part of my layout that you see when you walk into the room, so I need to be sure this yard is symmetrical as it will become an immediate focal point. The help you all provide is incredible! My appreciation and thanks.
Glad that was helpful. Just to keep things interesting, here is a trick you might want to consider to save some space (and don't we all). You can put the ladder track at a sharper angle than #7 but still use #7 turnouts if you allow for a short length of curvature between the diverging route and the yard track. Here is an example: The bottom plan is a standard #7 ladder like I drew above with 1.25" spacing. The top plan has the ladder at a #5 angle with short curved segments joining the yards tracks (with 1.25" spacing again). Some numbers: the straight section between turnouts in the ladder is 13/32 (much shorter than before) and the curved section is about 1 3/4" length of 22 1/2" radius (quite gentle). In the diagram, the short segment of red & green is the curved bit: red is pure 22 1/2" curve, green is an easement, but you wouldn't need to be that careful about it. With a standard #7 ladder at 1.25" spacing, you lose 8.75" of length (116 scale feet) in each successive yard track -- twice that for a standard double-ended yard (unless you make it diamond shaped). With the #5 ladder (#7 turnouts) you only lose 5*1.25" = 6.25" per track. The catch is that you don't get the full 1.25" spacing in the curved sections, but there is still enough clearance to avoid fouling since 1.25" is generous to start with. Cheers, Gary
Hutch! I'm going to throw in my 2ยข in here. The track centers are NOT determined by the #switch you use! Instead, they are pre-established by the design. The rub comes when you need to make 1" track centers and are using, for example, #12 switches. This creates a situation where you need to build complex scratchbuilt track switches that do what you want them to do. So the smaller the switch number you use, the easier it is to use a commercial made switch that will require spacing of some amount between the switches. The prototype doesn't care, it just builds what it needs to. Not so easy for us modelers.
Hutch IF my RR track software is correct Atlas C80 #4 = 1.22 on center, # 6 1.05 Peco 55 304mm = 0.89 on center 457mm 0.95" 914mm 1.1" This is with the turnouts end on end. I can't check because I'm still looking for layout room, but this means you should be able to space your turnouts. I guess my point is that IF this or any other SW gives an accurate depiction of the track ( I know this SW is perfect in O scale) then it may be cheaper faster to buy the software than to experiment with different turnouts to get the look you want. Also - a while back someone posted a yard "rule of thumb" ~If I cant fit my thumb between the cars, I'm gonna knock em over.
All of this is starting to make sense.... The detail I omitted is that my #7 code 55 switches are 8" long, a Fasttracks jig. That is why I am see slightly different measurements between the switches than what the software is saying.... On a funny note, I just broke out the white paint to paint over all of the diagonal lines I had drawn so I could start fresh as soon as it dries. The whole reason for doing this is to make sure my roadbed ends up in the right place. I know some use sheet roadbed in yards, but I plan to use the ballast to level it all up. I think 1.25 inch centerlines will give me enough room, I guess time will tell.
I just wish I actually had the skills to hand lay this area. It would be really nice... But that is something I am not sure I have the patience for.
Umm... If referencing my earlier post, I know all about frog angles. Nor was I noting physical size. As stated in that message, I merely meant that six is a smaller number than a seven. Boxcab E50
Wait.... 6 needn't be smaller than 7. I mean there are steroids, there could be font selections... Point being posts are great, but you can never get the whole picture based on someones few sentences. Lets try to assume that someone trying to help, might have a broader understanding than the few sentences they put down. Except me, I still haven't a clue and can't tell a frog, from frog snot.
Thank you ALL, this whole discussion taught me many things I had always taken for granted. Now that my paint has dried, I have the new line drawn, and the #7 switches being 8" long will work out perfectly on the 1.25 centers. The angled line is steeper than 1:7, but not by much. The key to this whole thing is that my switches are 8" long, if not, spacer sections would be required. My error was assuming #7 switches required a 1:7 line being drawn in the ladder. This is NOT always true and wasn't true in my particular case.
