Parallel double loop?

If you use O42 and O54 sectional curves, you should be able achieve your goal.  If you use O54 curves on both loops, it's a lot harder to achieve regular spacing, like it's not going to happen.

GRJ's point is the math, 8 ft. =96 inches, 2x54=108, more or less. Sounds like time for a sectional  test ?

Never make light of a 12x8 size layout. Any size is better than no layout at all. 

@GVDobler posted:

Never make light of a 12x8 size layout. Any size is better than no layout at all. 

Yeah, I’m a part time college student currently and still live at home. I’m building it partially for me, and partially for my younger brother. My mom isn’t exactly okay with me using half the basement, otherwise it’d be much bigger. One day I’ll have something much bigger, I’m sure!

Why not use GarGraves Flex Track? Then you can make your curves any radius you want. You don’t need to be tied down to sectional track dimensions.

It's busy, but here's something to consider. The switch examples show the center-to-center spacing of the combinations (might not be exact). The blue loop is O54 and the orange loop is O42 (except the bottom Ross example). The green switches show the spacing on the other sides. The inserts show the different look you're going to get with various combinations. However, by adding some custom cut fillers between the switches in the GarGraves example, you can achieve a more concentric look with about 6" of clearance.

Atlas track system, at one time had curves for 9" diameter increments.   O27, O36, O45, O54, O63, O72, O81, O90,    My layout,  small, was O45 inner, O54 outer with mostly O54 switches.   At one time Atlas provided a free design software, long gone.

Atlas, Gargrave, Ross, you can create custom pieces as need.  IMO.  Mike CT.

@jaketrainz posted:

Yeah, I’m a part time college student currently and still live at home. I’m building it partially for me, and partially for my younger brother. My mom isn’t exactly okay with me using half the basement, otherwise it’d be much bigger. One day I’ll have something much bigger, I’m sure!

Nothing wrong with a 12 x 8, I've lived with less.

@Rich Melvin posted:

Why not use GarGraves Flex Track? Then you can make your curves any radius you want. You don’t need to be tied down to sectional track dimensions.

True, but it's not as easy as sectional track if you want to make something quickly.  Given the situation, the sectional track is a lot quicker to build something that you can reuse the track when you move.  I suspect that Jake will be moving at some point not too many years from now, it would be nice to have track you could reuse.

FWIW, I'm using a lot of GarGraves Flex in my layout, but this sucker is going to be here until I'm on the dark side of the grass, I'm not doing this again.

There should be a lot of used, second hand track available.  My friend Tom B., did his layout with all used Gargrave track, Gargaves and Ross switches. Double parallel loops.

Train clubs, Train meets, This forum, the internet, good sources for used track. IMO. 

Just avoid used Gargraves Flex track, once it's dried out, it's a lot harder to bend, and the results are not as good as new track.  Sectional track, no problem.

Here's another example of using different GarGraves switches. I added the yellow bars to designate 3" spacing from the edges. The top switches are O-42 on the curves to give a smooth transition between loops. The bottom switches show how using the O-72 switches on the left gives a somewhat smoother transition than the O54 switches on the right. The big difference between GarGraves and other brands is the lack of small filler tracks, so you end up having to make custom cuts (green tracks). However, that makes for fewer joints that may cause problems, so it's generally a tradeoff.

@DoubleDAZ posted:

Here's another example of using different GarGraves switches. I added the yellow bars to designate 3" spacing from the edges. The top switches are O-42 on the curves to give a smooth transition between loops. The bottom switches show how using the O-72 switches on the left gives a somewhat smoother transition than the O54 switches on the right. The big difference between GarGraves and other brands is the lack of small filler tracks, so you end up having to make custom cuts (green tracks). However, that makes for fewer joints that may cause problems, so it's generally a tradeoff.

I’ve thought about that too, but I would prefer to avoid cutting track if possible. Any combination that works with either O-54 or O-42 switches that still gives me a parallel loop?

Edit: or any precut filler sections available?

Further edit: What size filler sections for O-54 and O-42?

Well, concentric is a tall order for GarGraves because of it's limited straight options and not wanting to cut, so here's as close as I could come trying various combinations. That doesn't mean some other combination wouldn't come closer, just that I don't have time or patience to try them all. There are 2 places where the tracks don't connect in software, but I'm confident they will in reality. The right side is about 2.8" wider than the left. I used O-72 switches, O-54 curves outside and O-42 curves inside.

@DoubleDAZ posted:

Well, concentric is a tall order for GarGraves because of it's limited straight options and not wanting to cut, so here's as close as I could come trying various combinations. That doesn't mean some other combination wouldn't come closer, just that I don't have time or patience to try them all. There are 2 places where the tracks don't connect in software, but I'm confident they will in reality. The right side is about 2.8" wider than the left. I used O-72 switches, O-54 curves outside and O-42 curves inside.

I see what you mean now. That gap is much larger than I want. I will likely be cutting then. I don’t have a saw but I have an uncle who does and who will be helping me with this layout anyway.

How does connecting the cut pieces work?

And what size would they need to be for either O42, O54, or O72 switches?

@Mike CT posted:

Atlas track system, at one time had curves for 9" diameter increments.   O27, O36, O45, O54, O63, O72, O81, O90,    My layout,  small, was O45 inner, O54 outer with mostly O54 switches.   At one time Atlas provided a free design software, long gone.

tlas, Gargrave, Ross, you can create custom pieces as need.  IMO.  Mike CT.

See attachment...should work.

-Greg

Visit your nearest ACE Hardware, $38.99.  Steel Grip 120 volt Corded Mini Cut-Off Saw

I use this for chopping the Gargraves track with a metal cutting abrasive wheel.  It makes a nice straight cut, then I just dress it with a tiny file and place the track piece.  This is especially useful if you're bending Gargraves Flex track.

It’s also worth mentioning, to anyone seeing this now, I am leaning toward Gargraves track and switches.

@jaketrainz posted:

How does connecting the cut pieces work?

Exactly the same as connecting full pieces, you use Gargraves pins.

@gunrunnerjohn posted:

Visit your nearest ACE Hardware, $38.99.  Steel Grip 120 volt Corded Mini Cut-Off Saw

I use this for chopping the Gargraves track with a metal cutting abrasive wheel.  It makes a nice straight cut, then I just dress it with a tiny file and place the track piece.  This is especially useful if you're bending Gargraves Flex track.

Not a bad price! Any specific cutting wheel you recommend?

I use one I bought on-line, it's an Aluminum Oxide 46 grit wheel.  I think it might be a good idea to go to a finer grit, in the 60-80 range.  It might make even smoother cuts.

You can get this with only 2 cuts (4 if you want the left side the same as the right). Left side is 4.8" wider than right. Center-to-center spacing on right side is 6.25".

@DoubleDAZ posted:

You can get this with only 2 cuts (4 if you want the left side the same as the right). Left side is 4.8" wider than right. Center-to-center spacing on right side is 6.25".

Going back to an example you gave earlier, what was the length of the cut section on the O54 crossover? I’ve circled what I’m talking about.

It's 4.60" in SCARM, but bear in mind that's cutting by eyeball, so it could be slightly more or less when built. I used O-72 because they give you a smoother transition, but if you prefer O-54 for whatever reason, here's what that would look like with 10 cuts as noted and 6"spacing. Note that I replaced the 12.4" straights with 37" straights. The problem is that if you don't want to 37" straights, they are .20" shorter (at least in SCARM) than a combination of all the other straights, so the geometry will change (2nd photo). If you want, I can redo it with 12.4". All that means though is that 6 of the cuts will be different, but there will still be 10 cuts. I attached the SCARM file, but I don't remember if you can open it using the Atlas version of SCARM. Either way, you won't be able to make changes.

I cheated, my two front loops are parallel- but side by side!

@DoubleDAZ posted:

It's 4.60" in SCARM, but bear in mind that's cutting by eyeball, so it could be slightly more or less when built. I used O-72 because they give you a smoother transition, but if you prefer O-54 for whatever reason, here's what that would look like with 10 cuts as noted and 6"spacing. Note that I replaced the 12.4" straights with 37" straights. The problem is that if you don't want to 37" straights, they are .20" shorter (at least in SCARM) than a combination of all the other straights, so the geometry will change (2nd photo). If you want, I can redo it with 12.4". All that means though is that 6 of the cuts will be different, but there will still be 10 cuts. I attached the SCARM file, but I don't remember if you can open it using the Atlas version of SCARM. Either way, you won't be able to make changes.

I downloaded the free version of SCARM and started playing around with it. If I put 2 O-72 switches together with no filler piece, the distance is 4.55in. Is that "enough" space? I've heard talk of 6in being the ideal spacing. I currently don't have any engines that require more than an O-31 curve (I'm coming from Lionel FT w/O-36 curves), but I do plan to maybe one day get some engines that require either O-42 or O-54, possibly articulated, but obviously nothing too big for O-54.

Edit: 5.5in seems to give me a perfectly parallel curve. Now that I have this software, I can figure out the custom cuts on my own. Glad I downloaded it!

You can probably get away with around 5" to 5.25" if you stick with O54 rated engines.  I'm going 6" as I found out that the 5.5" spacing at the club isn't enough for the Vision Line Big Boy and on the next track 21" passenger cars.   Happy to say the Big Boy just pushed them out of the way and continued on it's way.

4.5" clearance is fine on straights, that's the spacing for the Atlas dual-track bridge. However, just because an engine and rolling stock work with O-31 curves, doesn't mean they don't have enough overhang to run into each other on the curves.

Here's an example of what I'm talking about and why folks like 6" spacing. If you keep the 4.5" spacing around the layout, the spacing on the curves becomes just over 4" because O-42 is not a concentric match for O-54. I don't know how close to scale these SD40 are, but you can see how the front of the engine on the inside curve overhangs toward the outside curve. You can also see how the body of the engine on the outside curve overhangs toward the inside curve. It's worse with long passenger cars. Now, you might be able to get away with the 4" clearance with your current equipment, but it might limit what you can run in the future. I know this is probably not a permanent layout, so that might not be an issue for you at this point.

The other issue is that no combination of O-42 and O-54 curves will be concentric without a spacer between the switches.

However, all that aside, I have to apologize. Because you didn't want to cut tracks, I didn't think to check to see what the minimum size spacer could be used to keep the curves concentric. Turns out they can be just 2" and the C2C spacing will be 5.25". So, I think this might be the absolute best you can do and there are still 10 cuts.

I put this together in SCARM. Still finding my way around the program, but everything fits ok. 6 custom cuts total. Obviously more if I add some sidings coming off the inner loop. Took me some experimenting to get the spacing correct. It's ever so slightly off when comparing the right and left sides, by less than 1/10th of an inch, but I think in practicality It'll work. I used flex track as stand-ins for the pieces that I'll need to cut.

Well, that will work. FWIW, here's a version that connects in SCARM and also a photo that compares this (orange) to the old one (blue). The 2 versions are on different layers in SCARM. The new version has plenty of space around the edges. Good luck with the build.

@DoubleDAZ posted:

Well, that will work. FWIW, here's a version that connects in SCARM and also a photo that compares this (orange) to the old one (blue). The 2 versions are on different layers in SCARM. The new version has plenty of space around the edges. Good luck with the build.

On break at work right now but I’ll download that when I get home. I do want some space for scenery and terrain. For anyone interested, it’s going to be made out of insulating foam atop a 12x8 custom table. When construction gets going, I’ll start a new post with pictures and place a link in this thread. Thanks everyone for all the advice. I’m looking forward to getting started in the next few coming weeks!