What will fit

[Stoby]

Hi folks    what OO Gauge radius track  will fit  on a Baseboard,      the width of the Baseboard is 3 foot    { 36 inches }

want to do a continious run      and would like 2 lines    or 3 if possible 

 

 

 

Edited June 21 by Stoby

[ntpntpntp]

Look up the radius for the Hornby curved track.  For example:
R1 = 371mm
R2 = 438mm
R3 = 505mm
... etc.

 

Your board is 3', that's 914mm edge to edge.   Track radius is measured as a centre line so you need to allow some space from the centreline to the edge otherwise your track will hang off the edge and/or your trains will overhang and hit a wall, or fall off onto the floor.  Derailments WILL happen sometimes 🙂   

So, your track diameter needs to be a bit less than 914mm, I'd suggest at least 25mm from centre line to the board edge. Two edges, so lets say a maximum diameter of something like 864mm.   Referring back to the radius measurements above and remembering that diameter = 2x radius:
R3 would be 1010mm which is obviously too large.   
R2 would be 876mm which might be pushing things a bit, it will just about fit but the outside edges of the track are going to be very close to the edge  🙂 
R1 would be 742mm.

So.. you can *just about* fit a double track oval into 3' using R1 and R2,  but as I say the outside oval will be dangerously close to the edge. Also some modern models don't like R1 curves so you may have to limit them to the outside oval. There are some models which really need R3 or greater.

There is a reason why the standard 6' x 4' or 8' x 4' sheet of ply has been the typical size for 00 train sets for decades 🙂 

 

Edited June 21 by ntpntpntp

[Stoby]

Many Thanks for the info  ntpntpntp  i will push it to 38 inch wide      that way i am safe with 2  lines  

Thanks Again 

 

[Going Spare]

The wider board will just about accommodate trains running on 2nd radius curves (particularly if the board is up against a wall) as the larger locomotives and coaches overhang the outside of the track on curves.  Also, if you still want two ovals, the inner one will have to use 1st radius curves and you will find you are limited as to the types of locomotive that will be able to run round the inner oval as 2nd radius is the generally-accepted minimum to run all locomotives in the range.

[atom3624]

I've often wondered, these R1, R2, etc., dimensions, do they refer to the radius of the inner, or outer rail, or the outermost line formed by the sleepers, similarly for the innermost, or even an averaged radius through the centre of the tracks?

Al.

[Going Spare]

Hornby measures from the centreline between the rails.

[ModelerXYZ]

Small locos can be run on Radius 1 curves. A double track R1 and R2 will work for you. Standard points are R2. XYZ

[ntpntpntp]

25 minutes ago, atom3624 said:

R1, R2, etc., dimensions, do they refer to the radius of the inner, or outer rail,...

Always the centreline.    I've never encountered anything else with the many brands I've known over the decades. 

When talking about and comparing track in general I would encourage people to quote the actual measurement not the arbitrary "Rx" number, as different manufactures use different radii in their track systems. 

[What About The Bee]

I think 3 rail O scale tubular track measured to the outside rail, NTP, not to the centerline.

Not that Stoby will encounter very much of that.

Bee

Edited June 21 by What About The Bee
Phrase order