Ok so tonight I started laying flex track on my new mini layout (small oval). It didn't take long to remember what frustrated me in the past about laying track. I suck at laying my flex track thru the curves. I keep ending up with a joint section in one of the curves that causes derailments. How do you guys do it. Heres the photo of what I'm working on, just an inch over 2' by 3' oval which 10 1/2 inch radius curves to the inside of the track. The curves are just big enough that I can't get away with not having a joint in a curve. Thanks for the help in advance, Joe
Hi Personally i stagger the joint so that each rail joint is about 2" apart. Then solder the joints. Carl
Basic rule: Solder the curves; gap the straights. If I was making your layout above, I would solder two pieces of flex track together twice and make two 180 degree curves. I would join those two 180 degree pieces at the straight sides. Bend gently and don't physically break or crack the solder joints. Once the curved solder joints are in place, it is very, very difficult to re-solder them successfully.
I solder my flex BEFORE laying it. That way it is straight, and will not kink when curved. Just allow for some ties to be removed as the rail slides, and trim the rail as needed when finished. I laid my helix using this method. I used glue to affix the track, and left about 2-3" of track unglued, to allow it to straighten a bit. Solder to that, allow to cool, and curve as needed. No kinks!
Okay simple math problem here. Basically you have two half circles joined by two straight sections. The hal circles have a radius of 10.5 inches to the inside rail. Usually a track radius is measured to the centerline of the track so let's increase the radius a bit to 11 inches. Now we are ready to work our math magic. Both half cirles would, if pushed together form a circle with a radius of 11 inches. That would give a diameter of 22 inches. The track would follow the perimeter [circumference] of the circle. So how much track do we need? The formula to find the circumference of a circle is C= D X pi, where D is the diameter and Pi is 22/7. Another way is C= 2R X Pi where R is the radius. Now we only want to know the circumference of half the circle so we will use the formula C/2 = R X Pi. Anyway the math works out like this; C = 11 X22/7 or C = 34.57 inches. This is longer than a length of Atlas flex track so I would solder two pieces together then form the half circle and make your cuts on the ends where the track is straight.
Those are tight curves, don't they make preformed sectional track for that use? sectional track is rigid so it seems like it would be better for that size curve?.....dave
Supergoat and all tuned in: This may sound complicated but really it isn't. This is difficult at best to describe in words. Pictures would do a better job. Allow me a shot at it. I like Inkaneer's math, Carlw and Tony Burzio's resolution to the problem. I've tried soldering in advance and didn't like the results as I had to resolder to smooth out the curve. I ended up with a straight section or a angle joint if I pre-soldered. Typically, I do as Carlw suggested gapping the rail joints. I go to the extreme of three inches apart. Place the sliding side of the track, on the outside of the curve with the solid side on the inside. Now, deliberately pull the sliding side out about three inches. Place the track down on the road bed and secure with track nails. Cut off the plastic spike heads, two or three on each side of where you anticipate the rail joiner to go. Place the rail joiner and push the rail halfway back into the rail joiner. Take the other track and pull out the sliding side of the rail, three inches. Run the rail through the plastic spike heads and into the waiting rail joiner. Secure the second section of track with the track nails and start all over again. The inside rail should come together normally. I seldom if ever, including on straight track put in rail joiners directly across from each other. The only exception being, when I use prefab sectional track as in a rerailer, Kato Unitrack switch, or as Tony B., describes. You will notice as you install the rest of the track that the distance between where the tracks are joined... will increase Ie., 3 inches to 4 or more inches. That's not a bad thing, at all...let it be and continue laying track. To secure the track, I run a bead of CA (cyanoacrylate) "Gap Filling" down the center of the track allowing it to flow into where the cork road bed meets or the center of the two pieces. After checking the gauge of the rails where I joined the tracks and making any needed adjustments, to correct gauge, I then run a bead over the ties, under the track and rail joiner securing both the rail and joiner. Honest, this procedure and the final results have never given me trouble with derailments. Oh, before I forget. You can then remove the track nails at some point in the future. Just don't glue over the track nails. This isn't my idea alone. I learned this from an article in Model Railroader back when I was a young adult... building HO Layouts. I hope this helps.
Thanks guys, I appreciate the help. I'll be picking up some more flex track this weekend at the Monroe train show. I'll keep ya posted with how it turns out.
