Crossovers

[Poppy1944]

I have an 18 inch radius oval and a 22 inch radius oval that I would like to connect with a left and right crossover.  Is the distance between the tracks on the crossovers just the right size to match the 4 inch difference in these two diameters?  If so, I could use one on each side of the oval and not worry about matching the length of the crossovers to the standard 9 inch straights.

Not much chance of that, I guess, so I have to use the two crossovers on the same side of the oval and make up the odd difference in track length with small straights.  But what is the length of the crossovers?  I've seen 21 inches, 21.25 inches, and 21.5 inches.  If they are 21 inches, then 2 would add up to 42 inches and a 3 inch straight would make 45, which matches 5 nine inch straights.  If that isn't the length, what combination do I need?

thanks

[Joe Satnik]

Dear Poppy1944,

http://www.bachmanntrains.com/home-usa/board/index.php/topic,11520.0.html

A 3" straight half-way around the 18"R curve on each end of the oval should work.

Hope this helps.

Sincerely,

Joe Satnik

[full maxx]

here is mine ...18" and 22" curves

[full maxx]

Dear Poppy1944,

http://www.bachmanntrains.com/home-usa/board/index.php/topic,11520.0.html

A 3" straight half-way around the 18"R curve on each end of the oval should work.

Hope this helps.

Sincerely,

Joe Satnik

I had to use the three in straights and its a great fit

[Joe Satnik]

Dear FM,

1 picture = 1000 words.

Thanks.

Sincerely, 

Joe Satnik

[full maxx]

I think pictures give a good visual explanation...no pun intended

[Poppy1944]

thanks for the help.  Never would have thought of that 3 inch addition to the 18 inch curves, but it sure sounds like a winner. 

[full maxx]

yeah it works flawlessly

[CG04]

OK guys,

Another question for you.  Will the three inch straight work if I have 24" on the outside and 22" on the inside

Clif

[CG04]

Well shuckins,

I figured that Joe Satnik would jump on this question for sure.

Clif

[Joe Satnik]

Hey, Clif,

Thanks for the kind words.  I've been a bit busy lately.  The "end of the month" came 3 days early.   

A couple of things are working against you here.   

1.)  24"R half-circles will not fit on a 4' wide sheet.

2.)  22"-24" concentric curve spacing is too close to avoid overhang crashes. 

http://www.nmra.org/standards/sandrp/s-8.html

(Scroll down to HO)

The idea is to match "crossover spacing" to the "difference in radii" between concentric curves. 

The centered 3" straight bumps out the ends of the 18"R curves (1-1/2" each side) to 19.5" effective radius. 

22" - 19.5" = 2-1/2" effective difference (at the end of the 'concentric' curves).   

This is as close as you're gonna get to the 2-3/8" spacing of the #6 crossover using the available EZ-Track fitter straights. 

By FM's experience, it seems to be "close enough" to work.

Hope this helps. 

Sincerely,

Joe Satnik 

[full maxx]

Hey, Clif,

Thanks for the kind words.  I've been a bit busy lately.  The "end of the month" came 3 days early.   

A couple of things are working against you here.   

1.)  24"R half-circles will not fit on a 4' wide sheet.

2.)  22"-24" concentric curve spacing is too close to avoid overhang crashes. 

http://www.nmra.org/standards/sandrp/s-8.html

(Scroll down to HO)

The idea is to match "crossover spacing" to the "difference in radii" between concentric curves. 

The centered 3" straight bumps out the ends of the 18"R curves (1-1/2" each side) to 19.5" effective radius. 

22" - 19.5" = 2-1/2" effective difference (at the end of the 'concentric' curves).   

This is as close as you're gonna get to the 2-3/8" spacing of the #6 crossover using the available EZ-Track fitter straights. 

By FM's experience, it seems to be "close enough" to work.

Hope this helps. 

Sincerely,

Joe Satnik 

yeah it works great and I know what you mean about the end of the month being three days early

[CG04]

Thanks Joe,

I knew you would come thru. 
I think I forgot to mention that I am going to at least 5' wide.  The layout will be a combination of three pieces of 4X8's with a one foot extension on at least two sides.  It will look kinda like a "C", but not quite.  What I have now is an "L", but that is standing on it's side against the bedroom wall.  We are moving and I am taking over the garage.

Thanks again to all.

Clif