Lionel Fastrack 45 Degree Double Track Crossover with O72 Switches

[Markettimer]

Good evening everyone.  Does anyone know any Lionel Fastrack configuration for a 45 degree double track crossover using 4 Lionel Fastrack O72 switches?  The switches align perfectly on the crossover but when I try to connect the straight track portions, they don't align with any track combination I can solve.  I've tried lengthening the crossover and the switches with 1/2 straights, 10 inch straights and 1.75 inch straights and I can't get it right.  Of course I'd like to keep the overall length and width as short/narrow as possible for space reasons.  Can anyone help?  Thanks!  Jim

[lionelsoni]

What are the lengths of the straight paths through the turnouts and the 45-degree crossing?

[Markettimer]

Please don't go to a lot of trouble here.  I thought perhaps that someone had built this before me and could share their design.  Anyway, the turnout is 15 1/2 inches straight, 14 1/2 O72 curve, which is the same as a standard Fastrack O72 single piece curve, 16 to a circle I believe.  The crossover is 10 inches straight.  When I have the switches connected to the crossover, the length of the straight that needs to be completed is exactly 8 inches.  I have the roadbed equipped extensions attached to the switches because that fills in the roadbed gaps.  I can't believe Lionel designed this so non-standard.  This is a pretty common type of trackage in many scales.  I think Gargraves or someone sells this configuration as a package actually.  Again, thanks for the help.

[lionelsoni]

Well, if 8 inches is what you need, you can make that with a 4 1/2 plus two 1 3/4 pieces.  But I would be interested in doing the geometry to see just how exact that 8 inches is.  As I understand it, the straight path through the turnout is 15 1/2 inches including the extension; and you also have a (straight) extension on the curved outlet of the turnout.  Exactly how long is that extension?  I calculate that the chord of the curved path (straight-line distance between the ends of the center rail) should be 14.047 inches.  Where did you measure your 14 1/2 inches?  Did you include the extension in that measurement?

(I don't have access to a single piece of Fastrack; and the Lionel website gives precious little information about the dimensions of their track.)

[Markettimer]

You solved it!  After you mentioned it, I realized Lionel made a 4 1/2 inch straight.  I had completely forgotten about that.  I have never bought any so I didn't have any laying around to try.  That's perfect!  Thanks!  Jim

[lionelsoni]

Jim, would you mind measuring the extensions and giving me the details that I was looking for in my last post?  I would like to work this out geometrically to improve my understanding of the quirks of Lionel's Fastrack; but I need someone like you to give me accurate measurements of the pieces, since they seem not to be recorded anywhere.

[USNRol]

Bob and Jim,

Thought I'd play with this problem in my track software...the results are below.  Bottom line is you can do it a couple ways but I think the best fit for the straights between switches will occur when using the 45 crossing with 1.375" "fitters" on all four ends.  This leaves a space of almost 10 7/8" between the switches which can be made up with 5", 4.5" and 1.375.  Otherwise without the fitters on the crossing the gapo to fill is about 8 1/4" which as close as I could come was 5"+1.75"+1.375=8 1/8" but a 1/8" gap is probably "Fudgable" in this setup.

Note the grid is 6" with 0.5" dots.  Also the crossing is equivalent to two 10" straights Bob.

Roland

[lionelsoni]

Roland, can you confirm that the straight path through the turnout is in fact 14 1/2 inches, not 15 1/2 as Jim said, and that the extensions are 1 3/8 inches?  It looks to me from reading the manual that those would be required on both paths unless one were willing to cut the roadbed.

It's a shame that Lionel couldn't have given these dimensions in their manual.

I think we may have lost Jim.

[USNRol]

Bob,
You are correct, you would need to use both 1 3/8 extensions which come with the turnout unless you were willing to cut the adjoining track. 

These 1 3/8 fitters are wired in the back and cut through the center rails for easily establishing blocked sections in your track. So, RRTrack is a bit misleading in that when you call up an 072 turnout it gives you just the bare turnout without the normally included 1 3/8" extensions.  So Jim's dual crossover should look like the below example rather than my above post. 

you could also use six 1 3/8" fitters to make up the 8.25" gap between the switches and it might fit better...I'm starting to lose faith in the accuracy of the dimensions in the RR Track software - either that or I still don't know exactly how to operate the program!

And Finally, the length of the through path on an 072 FasTrack turnout depends on whether you use the extension or not but assuming you do it about 15 5/8".

 

Roland 

[lionelsoni]

Thanks!  I'm going with a straight path of 15 5/8 inches, including a 1 3/8-inch extension; a 22.5-degree 36-inch radius curved path plus a 1 3/8-inch extension; and a 45-degree crossing with 10-inch paths.  I figure that the straight track between turnouts should be

2 * 36 * sin(22.5 degrees) + (2 * 1.375 + 10) * cos(22.5 degrees) - 2 * 15.625 = 8.083

which is about 8 1/16; so 8 and 8 1/8 are both reasonable approximations.

I have calculated all the possible combinations of the standard 1 3/8, 1 3/4, 4 1/2, 5, and 10-inch pieces, which I will post here for anyone trying to fit a particular length in the future:

 1 3/8 = 1 3/8
 1 3/4 = 1 3/4
 2 3/4 = 1 3/8 + 1 3/8
 3 1/8 = 1 3/4 + 1 3/8
 3 1/2 = 1 3/4 + 1 3/4
 4 1/8 = 1 3/8 + 1 3/8 + 1 3/8
 4 1/2 = 1 3/4 + 1 3/8 + 1 3/8
 4 1/2 = 4 1/2
 4 7/8 = 1 3/4 + 1 3/4 + 1 3/8
 5     = 5
 5 1/4 = 1 3/4 + 1 3/4 + 1 3/4
 5 1/2 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
 5 7/8 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
 5 7/8 = 4 1/2 + 1 3/8
 6 1/4 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
 6 1/4 = 4 1/2 + 1 3/4
 6 3/8 = 5 + 1 3/8
 6 5/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
 6 3/4 = 5 + 1 3/4
 6 7/8 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
 7     = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
 7 1/4 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
 7 1/4 = 4 1/2 + 1 3/8 + 1 3/8
 7 5/8 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
 7 5/8 = 4 1/2 + 1 3/4 + 1 3/8
 7 3/4 = 5 + 1 3/8 + 1 3/8
 8     = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
 8     = 4 1/2 + 1 3/4 + 1 3/4
 8 1/8 = 5 + 1 3/4 + 1 3/8
 8 1/4 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
 8 3/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
 8 1/2 = 5 + 1 3/4 + 1 3/4
 8 5/8 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
 8 5/8 = 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8
 8 3/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
 9     = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
 9     = 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8
 9     = 4 1/2 + 4 1/2
 9 1/8 = 5 + 1 3/8 + 1 3/8 + 1 3/8
 9 3/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
 9 3/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8
 9 1/2 = 5 + 1 3/4 + 1 3/8 + 1 3/8
 9 1/2 = 5 + 4 1/2
 9 5/8 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
 9 3/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
 9 3/4 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4
 9 7/8 = 5 + 1 3/4 + 1 3/4 + 1 3/8
10     = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
10     = 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
10     = 5 + 5
10     = 10
10 1/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
10 1/4 = 5 + 1 3/4 + 1 3/4 + 1 3/4
10 3/8 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
10 3/8 = 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
10 3/8 = 4 1/2 + 4 1/2 + 1 3/8
10 1/2 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
10 1/2 = 5 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
10 3/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
10 3/4 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
10 3/4 = 4 1/2 + 4 1/2 + 1 3/4
10 7/8 = 5 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
10 7/8 = 5 + 4 1/2 + 1 3/8
11     = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
11 1/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
     
11 1/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
11 1/4 = 5 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
11 1/4 = 5 + 4 1/2 + 1 3/4
11 3/8 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
11 3/8 = 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
11 3/8 = 5 + 5 + 1 3/8
11 3/8 = 10 + 1 3/8
11 1/2 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
     
11 1/2 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
11 5/8 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
11 3/4 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
11 3/4 = 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
11 3/4 = 4 1/2 + 4 1/2 + 1 3/8 + 1 3/8
11 3/4 = 5 + 5 + 1 3/4
11 3/4 = 10 + 1 3/4
11 7/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
     
11 7/8 = 5 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
12     = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
12 1/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
12 1/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
12 1/8 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/8
12 1/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
     
12 1/4 = 5 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
12 1/4 = 5 + 4 1/2 + 1 3/8 + 1 3/8
12 3/8 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
12 1/2 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
12 1/2 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
12 1/2 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/4
12 5/8 = 5 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
12 5/8 = 5 + 4 1/2 + 1 3/4 + 1 3/8
12 3/4 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
12 3/4 = 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
12 3/4 = 5 + 5 + 1 3/8 + 1 3/8
12 3/4 = 10 + 1 3/8 + 1 3/8
12 7/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
       + 1 3/8
12 7/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
13     = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
13     = 5 + 4 1/2 + 1 3/4 + 1 3/4
13 1/8 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
13 1/8 = 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
13 1/8 = 4 1/2 + 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8
13 1/8 = 5 + 5 + 1 3/4 + 1 3/8
13 1/8 = 10 + 1 3/4 + 1 3/8
13 1/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
       + 1 3/8
13 1/4 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
13 1/4 = 5 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
13 3/8 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
13 1/2 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
13 1/2 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
13 1/2 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8
13 1/2 = 4 1/2 + 4 1/2 + 4 1/2
13 1/2 = 5 + 5 + 1 3/4 + 1 3/4
13 1/2 = 10 + 1 3/4 + 1 3/4
13 5/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
       + 1 3/8
13 5/8 = 5 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
13 5/8 = 5 + 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8
13 3/4 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
13 3/4 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
13 7/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
13 7/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
     
13 7/8 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8
14     = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
       + 1 3/4
14     = 5 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
14     = 5 + 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8
14     = 5 + 4 1/2 + 4 1/2
14 1/8 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
14 1/8 = 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
14 1/8 = 5 + 5 + 1 3/8 + 1 3/8 + 1 3/8
14 1/8 = 10 + 1 3/8 + 1 3/8 + 1 3/8
14 1/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
14 1/4 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
     
14 1/4 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4
14 3/8 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
14 3/8 = 5 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8
14 1/2 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
14 1/2 = 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
14 1/2 = 4 1/2 + 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
14 1/2 = 5 + 5 + 1 3/4 + 1 3/8 + 1 3/8
14 1/2 = 5 + 5 + 4 1/2
14 1/2 = 10 + 1 3/4 + 1 3/8 + 1 3/8
14 1/2 = 10 + 4 1/2
14 5/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
       + 1 3/8 + 1 3/8
14 5/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
     
14 5/8 = 5 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
14 3/4 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
14 3/4 = 5 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4
14 7/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
14 7/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
14 7/8 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
14 7/8 = 4 1/2 + 4 1/2 + 4 1/2 + 1 3/8
14 7/8 = 5 + 5 + 1 3/4 + 1 3/4 + 1 3/8
14 7/8 = 10 + 1 3/4 + 1 3/4 + 1 3/8
15     = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
       + 1 3/8 + 1 3/8
15     = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
     
15     = 5 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
15     = 5 + 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
15     = 5 + 5 + 5
15     = 10 + 5
15 1/8 = 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
15 1/8 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
15 1/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
15 1/4 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8
15 1/4 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
15 1/4 = 4 1/2 + 4 1/2 + 4 1/2 + 1 3/4
15 1/4 = 5 + 5 + 1 3/4 + 1 3/4 + 1 3/4
15 1/4 = 10 + 1 3/4 + 1 3/4 + 1 3/4
15 3/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
       + 1 3/4 + 1 3/8
15 3/8 = 5 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
15 3/8 = 5 + 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
15 3/8 = 5 + 4 1/2 + 4 1/2 + 1 3/8
15 1/2 = 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
15 1/2 = 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
15 1/2 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
15 1/2 = 5 + 5 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
15 1/2 = 10 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
15 5/8 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
15 5/8 = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
       + 1 3/8
15 5/8 = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
15 3/4 = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
       + 1 3/4 + 1 3/4
15 3/4 = 5 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
15 3/4 = 5 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8
15 3/4 = 5 + 4 1/2 + 4 1/2 + 1 3/4
15 7/8 = 1 3/4 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
15 7/8 = 4 1/2 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8 + 1 3/8
15 7/8 = 4 1/2 + 4 1/2 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
     
15 7/8 = 5 + 5 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
15 7/8 = 5 + 5 + 4 1/2 + 1 3/8
15 7/8 = 10 + 1 3/4 + 1 3/8 + 1 3/8 + 1 3/8
15 7/8 = 10 + 4 1/2 + 1 3/8
16     = 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
       + 1 3/8 + 1 3/8 + 1 3/8
16     = 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/8
       + 1 3/8
16     = 4 1/2 + 4 1/2 + 1 3/4 + 1 3/4 + 1 3/4 + 1 3/4
16     = 5 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8 + 1 3/8
       + 1 3/8

Beyond these lengths, every 1/8-inch multiple can be gotten by one of these plus 5 or 10-inch pieces.  Note that 8, 8 1/8, and 8 1/4 are all on the list, although I believe that 8 1/4 is too long.  That is just as well, since it requires six small pieces.

[bfskinner]

Thanks Bob! A tour de force.

[lionelsuperotrack]

Lionelsoni - Do you mind if I post your work on the FasTrack Yahoo Group? Would give you full credit. Please advise.

Mike Spanier ([e-mail])

[lionelsoni]

Go for it.

[USNRol]

Great gouge Bob...I was always meaning to do this for myself but always found it faster just to fiddle with the pieces on the floor (and more fun) but this is handy! 

Interesting to note that in addition to offering decent-to-considerable flexibility of lengths for distances between 1 3/8" and 11", beyond 11" ANY 1/8" incremental length can be achieved without having to cut track.  Many people see inflexibility and difficulty cutting custom sections as a detractor for FasTrack; this may be over-rated.

Roland