lionel fast track 60" turnout

It will not make a circle. It is part of the design geometry. The FasTrack orphan. The divergent track arc is too long when the 1 3/8" 1/2 roadbed piece is installed. The are not partial O60 curves to make it fit.

I don't recall now, but, I was thinking that perhaps cutting the half-road bed off of a curve to mate to the turnout would work. 

Would you post a photo of the switch on top of curve so that I could observe how the ends align? I don't have any O60.

You would cut the ballast off the appropriate side to match the switch curve end without the 1 3/8" filler piece. It looks like it fits in SCARM and RR-Track that way.

Thank you. Your response reinforced my suspicion. I can solve by adding 1 3/4 and 1 3/8" at several locations to reduce the gap to less than 1/4" which is easy to close with fast track. I normally would use Atlas track which has no problems with closures but I want this set to be played with by my grandchildren. Fast Track is the only option since I don't like MTHs track. Enjoy today. D

I am in the middle of redoing my crappy basement floor layout, doing it in a CAD program, and come across about an inch that just could NOT be explained. I went and checked dimensions. Come to find out O72 is not 72" in diameter, its more like 71-3/8" for the center rail. Then I have some K-Line O81 that isn't even listed on the website. Yup, not 81, not 80. Make another circle of track, push the circle until the two diameters are about the same, then use that number.

Then I laid a piece of 1930's O72 track onto a K-Line O72 switch, the diameters match, but the switch is NOT 360/16 or 22.5 degrees of a circle! Will whaddaya know. So the same problem you are having.

I was measuring the length of the chord, and using some trigonometry and the assumption the track is a perfect circle (it isn't), nope, not 72" diameter, 36" radius. Work has a CMM machine but I don't know how to use it and prefer to remain employed.

illinoiscentral posted:

I am in the middle of redoing my crappy basement floor layout, doing it in a CAD program, and come across about an inch that just could NOT be explained. I went and checked dimensions. Come to find out O72 is not 72" in diameter, its more like 71-3/8" for the center rail. Then I have some K-Line O81 that isn't even listed on the website. Yup, not 81, not 80. Make another circle of track, push the circle until the two diameters are about the same, then use that number.

Then I laid a piece of 1930's O72 track onto a K-Line O72 switch, the diameters match, but the switch is NOT 360/16 or 22.5 degrees of a circle! Will whaddaya know. So the same problem you are having.

I was measuring the length of the chord, and using some trigonometry and the assumption the track is a perfect circle (it isn't), nope, not 72" diameter, 36" radius. Work has a CMM machine but I don't know how to use it and prefer to remain employed.

You can download SCARM for free and use it's libraries for the chord lengths of curves. You can also measure quite accurately with the measure tool for the lengths. The author, Milen Piev, obtains each manufacturer's specifications before adding a library. Hover the cursor over a track item in the library and the data will appear. Select a track on the layout plan and the data is in a window on the low left corner.

The manufacturers of three rail products all make different assumptions. Two rail scale is just like real railroading and the formulas will work.

DennisTiro posted:

Thank you. Your response reinforced my suspicion. I can solve by adding 1 3/4 and 1 3/8" at several locations to reduce the gap to less than 1/4" which is easy to close with fast track. I normally would use Atlas track which has no problems with closures but I want this set to be played with by my grandchildren. Fast Track is the only option since I don't like MTHs track. Enjoy today. D

 

That works for simplicity, if you are getting full quarter circles. Space/fit at the 90° points. It is really easy to cut the roadbed of a curve to fit the divergence without a fitter. Just depends on the situation what solution will be best.

The other tracks and circles of FasTrack work just fine. It is based on 6" center to center. The O36/O48 double main naturally and the O74/O84 double main naturally as well as O96, but no switches. The O31 is a stand alone and won't fit parallel to O36.

Have fun!

Thank you. With SCARM I am close enough. D