Trains.com

Fastrack curve sizes

8636 views
6 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    April 2003
  • 305,205 posts
Fastrack curve sizes
Posted by Anonymous on Wednesday, January 4, 2006 6:41 PM
Where are the FasTrack circle curve sizes measured from to get there size of 036,048,etc? Outside rail to outside rail, center rail to center rail,inner rail to inner rail or road bed to road bed?
  • Member since
    December 2005
  • From: 28 Sager Place Irvington, NJ 07111
  • 265 posts
Posted by LS1Heli on Wednesday, January 4, 2006 7:20 PM
It has nothing to do with the roadbed. The diameter is the diameter of the curve that the engine is physically making. Outer rail to outer rail.
  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Wednesday, January 4, 2006 7:29 PM
Thanks much.
  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Wednesday, January 4, 2006 8:24 PM
An O36 circle will take about 40"including the roadbed.
  • Member since
    December 2005
  • From: Hopewell, NY
  • 3,230 posts
Posted by ADCX Rob on Thursday, January 5, 2006 12:37 AM
QUOTE: Originally posted by LS1Heli

It has nothing to do with the roadbed. The diameter is the diameter of the curve that the engine is physically making. Outer rail to outer rail.


LS1Heli,

Unfortunately, to confuse things even more, Lionel has actually designed the Fastrack system to be measured center rail - to - center rail. The O36 section circles are precisely 36" in diameter measured center rail - to - center rail, and the roadbed is 3 11/32" wide, so a circle takes up 39 11/32", or just shy of the 40" as Houdy indicates.

One problem with the Fastrack geometry is that the "O36" straights should be 12.73" long, the 90 degree crossings should be 10.54" across, and the 45 degree crossings should be 14.91" across. If this were the case, you wouldn't need so many small "fitter" sections for standard track layout configurations.

Rob

Rob

  • Member since
    December 2001
  • From: Austin, TX
  • 10,096 posts
Posted by lionelsoni on Thursday, January 5, 2006 11:15 AM
From an old thread:

I stopped by a hobby shop on the way home from work and measured a piece. The center rail distance was very close to 13 2/4 inches, which works out to a radius of 17.965241 inches, or very nearly 18. Working back from the radius to the chord gives 13 25/32 inches, only 1/32 more than I measured with the old yardstick that was at hand. So, obviously, the diameter is meant to be 36 inches between center rails.

(The roadbed is 3 3/8 inches wide. So Roger's measurement is very close to the outside diameter of 39 3/8 inches. If Lionel had named fastrack in the same way they do tubular track, it would have been called O39.)

Bob Nelson

  • Member since
    December 2005
  • From: Long Island, NY
  • 456 posts
Posted by darianj on Thursday, January 5, 2006 12:19 PM
QUOTE: One problem with the Fastrack geometry is that the "O36" straights should be 12.73" long, the 90 degree crossings should be 10.54" across, and the 45 degree crossings should be 14.91" across. If this were the case, you wouldn't need so many small "fitter" sections for standard track layout configurations.


WOW...Someone was really paying attention in Geometry![tup]
There's light at the end of the tunnel.... It's a Train! http://www.tmbmodeltrainclub.com

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

FREE EMAIL NEWSLETTER

Get the Classic Toy Trains newsletter delivered to your inbox twice a month