Understanding Curve Radius

The smallest commercially available would be the common 12.37" radius tubular O-27, then for FasTrack would be the 15.5" radius O-31, which makes a circle of track that is 35" in overall diameter including the built-in roadbed.

Your question is a little confusing to me. You asked the smallest radius curve, which for FasTrack is O31. It would definitely work in a 8'x10' area. Could you have meant to ask the largest radius (diameter) track?

What is your vision of what your layout to be? Scale or traditional?Multiple track elevations or primarily one elevation? Multiple trains in operation at the same time or only one or two?

Do you mean largest?

Fastrack comes in 084 which would fit within the 8ft you have available.

ADCX Rob posted:

The smallest commercially available would be the common 12.37" radius tubular O-27, then for FasTrack would be the 15.5" radius O-31, which makes a circle of track that is 35" in overall diameter including the built-in roadbed.

Thanks

TM Terry posted:

Your question is a little confusing to me. You asked the smallest radius curve, which for FasTrack is O31. It would definitely work in a 8'x10' area. Could you have meant to ask the largest radius (diameter) track?

What is your vision of what your layout to be? Scale or traditional?Multiple track elevations or primarily one elevation? Multiple trains in operation at the same time or only one or two?

I guess I meant to say largest radius diameter. I was planning to run perhaps 3 tracks O scale mostly one elevation.

Many thanks.

tr18 posted:

Do you mean largest?

Fastrack comes in 084 which would fit within the 8ft you have available.

Thanks

Thoriginalrocker posted:

tr18 posted:

Do you mean largest?

Fastrack comes in 084 which would fit within the 8ft you have available.

Thanks

The O84 will use about 87.5" of the 96" when measured from the outside edge of the roadbed to the outside edge of the roadbed.

The sizing of O track is actually a diameter of the center rail.

Thoriginalrocker posted:

TM Terry posted:

Your question is a little confusing to me. You asked the smallest radius curve, which for FasTrack is O31. It would definitely work in a 8'x10' area. Could you have meant to ask the largest radius (diameter) track?

What is your vision of what your layout to be? Scale or traditional?Multiple track elevations or primarily one elevation? Multiple trains in operation at the same time or only one or two?

I guess I meant to say largest radius diameter. I was planning to run perhaps 3 tracks O scale mostly one elevation.

Many thanks.

for three mains you could use the Fastrack 084, 072 and 060 curves.

Moonman posted:

The sizing of O track is actually a diameter of the center rail.

True for FasTrack & Super "O", not so for other track systems(some are even varied within their own line(s) of track whether they adhere to center rail radius or not).

Junior High Math - - diameter is the width of the circle for a line through the center, Radius is the distance from the center to outside, it is exactly 1/2 the diameter.     The diameter and radius are not the same, but are very close relatives.

Generally, three railers use diameter to describe curves.    Two railers regardles of scale (N, HO, O etc.) generally use radius.  

tr18 posted:

Thoriginalrocker posted:

TM Terry posted:

Your question is a little confusing to me. You asked the smallest radius curve, which for FasTrack is O31. It would definitely work in a 8'x10' area. Could you have meant to ask the largest radius (diameter) track?

What is your vision of what your layout to be? Scale or traditional?Multiple track elevations or primarily one elevation? Multiple trains in operation at the same time or only one or two?

I guess I meant to say largest radius diameter. I was planning to run perhaps 3 tracks O scale mostly one elevation.

Many thanks.

for three mains you could use the Fastrack 084, 072 and 060 curves.

Thanks great information !

Keep in mind, if you go for the largest curve that will fit your space (084), you will only have about a 30" straight on the 10' side. You might want to downsize that to 072 or even 060.

Big_Boy_4005 posted:

Keep in mind, if you go for the largest curve that will fit your space (084), you will only have about a 30" straight on the 10' side. You might want to downsize that to 072 or even 060.

Elliot, excellent point

For smallest radius, O-27 is what it is, standard tubular is O-31. I'm pretty sure that the smallest Fastrack is O-36, not O-31. Personally, I'd go with O-54 Fastrack so you can accommodate larger pieces while still maintaining adequate straight section length. 

Keith6700 posted:

For smallest radius, O-27 is what it is, standard tubular is O-31. I'm pretty sure that the smallest Fastrack is O-36, not O-31. Personally, I'd go with O-54 Fastrack so you can accommodate larger pieces while still maintaining adequate straight section length. 

Lionel has added an 031 in Fastrack this past year. The problem is it will not fit inside an 036 circle.

Thoriginalrocker posted:

I am just starting a layout using Lionel fas-track. My platform is 8' by 10', the 8' side will have the curves and the 10' side will be straight track.

What would be the smallest radius curve that would fit and work well within the 8' space for the outside loop? 

Many thanks  :-)

Regardless of what diameter curve you will use (radius is one-half of diameter), your "platform" is too wide.  You cannot reach more than 30 inches.  People routinely have laid their track where it can't be reached.  You will have to clean, maintain and possible repair or replace track.  There will be electrical issues and/or "dead spots" from time to time.  The last thing you want to do is climb on your layout.  

Arrange your track pieces so that any area on your layout may be reached with 30 inches.  If you think you can build it perfectly and will never need to, you are kidding yourself.

You may want to consider a track arrangement in the shape of an open letter like: L, C, etc.  

Do NOT, NOT, NOT climb on your platform.  There is a better and smarter way.

You will find it very convenient and useful to simply walk up to your track-work and your knees and back will love you for it!  

Elliot said:  "Keep in mind, if you go for the largest curve that will fit your space (084), you will only have about a 30" straight on the 10' side. You might want to downsize that to 072 or even 060."

Excellent point. Visualizing your platform, it's almost a square. So, there will be very little opportunity for a long straight run, before the train needs to start turning for the next curve.  Is there any chance that you can change the proportions of the table to make it skinnier and longer? Or are you constrained by the room size or the opinions of the other members of the (ahem) management team?

ORIGINALROCKER,

   There is one more thing you need to consider, if you want to run all your engines and rolling stock.  You must purchase the size curves that your engine and rolling stock is rated to run on or bigger, if you already have engines and rolling stock.  If you already own 036 type engines and rolling stock, no problem.  However if you happen have a TMCC JLC Scale GG1, you must run on 072 and bigger curved track, thru out your layout.  Most people have smaller engines and rolling stock, however make sure what you already own prior to purchasing a lot of track.  Also if you plan on running Tin Plate Trains, I recommend 048 and bigger FasTrack & 048 Command Control Switches, in fact most all of mine are 060 and bigger.  As was mentioned before 031 FT will not fit inside 036 FT, however you can run 031 RealTrax inside 036 FT, notice the difference in the make of the inside track, on my 1st level.  

PCRR/Dave