What curved tracks should I buy?

[arbasu]

I am planning 2 concentric oval tracks. I have a current 18" curve tracks.
What curvature should the outside oval track be - 22" ?
Also, if I use 22" for the outside track and I wish to use a crossover-turnout on the straight part of the oval tracks (to cross between the inner and outer tracks) then will a 18" and 22" curved ones fit with the 21.5" crossover turnouts?

[ABC]

22" radius will work fine

[Joe Satnik]

Dear arbasu,

Track center-line to center-line spacing of the crossovers is 2-3/8". 

You will need to widen the inner (18"R) oval by 3-1/4".

Hope this helps.

Sincerely,

Joe Satnik

[full maxx]

Dear arbasu,

Track center-line to center-line spacing of the crossovers is 2-3/8". 

You will need to widen the inner (18"R) oval by 3-1/4".

Hope this helps.

Sincerely,

Joe Satnik

so does this mean that 22 will be fine as in the above post or does the 18" need a 3" piece of track in the middle of the half circles but then would that not be almost 22" and the track would hit...I am unclear of what you are saying...sorry maybe I'm just dense

[arbasu]

Thanks for the guidance!

But I see only 2.25" track extensions - how do I make a 3.25" ?

[ABC]

You can cut a piece of flex track to fit, and put a roadbed (cut it to fit in between) under it then ballast it similarly to the existing E-Z track.

[full maxx]

Dear arbasu,

Track center-line to center-line spacing of the crossovers is 2-3/8". 

You will need to widen the inner (18"R) oval by 3-1/4".

Hope this helps.

Sincerely,

Joe Satnik

so does this mean that 22 will be fine as in the above post or does the 18" need a 3" piece of track in the middle of the half circles but then would that not be almost 22" and the track would hit...I am unclear of what you are saying...sorry maybe I'm just dense

still unclear

[Joe Satnik]

The 3" straight is probably close enough.  Keep the crossovers in the middle of the long straight sides of the ovals to minimize the effect of the 1/4" error.   

4" radius difference (22"-18") minus the 2-3/8" crossover separation = 1-5/8" error on each side, X 2 sides = 3-1/4".

Hope this helps.

Sincerely,

Joe Satnik