Inside and outside track radii

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centenary
Posts: 94
Joined: Thu Sep 03, 2009 3:08 pm

Inside and outside track radii

Postby centenary » Thu May 02, 2019 4:51 pm

Hello. Sorry if this is an obvious answer to the more knowledgable. If I want to lay two parallel tracks on a curve and Im not using flexi track, can I use say 3rd radius inside and outside track or does the outside have to be 4th radius to look best and spacing?

Dad-1
Posts: 5845
Joined: Sun Aug 24, 2008 8:05 pm
Location: Dorset - A mile from West Bay.

Re: Inside and outside track radii

Postby Dad-1 » Thu May 02, 2019 5:04 pm

You'll need to have 4th Radius outside if your inner tracks are 3rd.
This should give you adequate clearence for coaches passing on
the two lines and keep an consistant gap
That is the basic principal of 1st; 2nd; 3rd; and 4th radius.

Geoff T.
Remember ... I know nothing about railways.
viewtopic.php?f=22&t=32187 and Another on viewtopic.php?f=22&t=28436&start=60&st=0&sk=t&sd=a

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6C
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Location: Pingvollr, dans le Wirrale

Re: Inside and outside track radii

Postby 6C » Sat May 04, 2019 11:55 am

Agree.

Be careful with 1st and 2nd radius as many of the latest models cannot manage certainly 1st radius - e.g. my lovely Bachmann ROD - and their instructions state this.. :wink:
Pete

Fetch me a bottle of your finest Chateau Bichon Frise '65 !!

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SRman
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Joined: Fri Oct 03, 2008 2:26 am

Re: Inside and outside track radii

Postby SRman » Sat May 04, 2019 12:01 pm

Definitely use the two different radii. For double track, ideally use 1st and 2nd, 2nd and 3rd, or 3rd and 4th radii, with the caveat mentioned by 6C that many newer items won't run on 1st radius.

If you tried to do parallel tracks with the same radius, you'll find that they converge as they go further round the circuit.

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centenary
Posts: 94
Joined: Thu Sep 03, 2009 3:08 pm

Re: Inside and outside track radii

Postby centenary » Sun May 05, 2019 8:47 pm

Thanks all. I wont be using any 1st radius curves and intend avoiding 2nd. Hoping to use 3rd as a minimum.


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