Fast Tracks

Model Railroading Discussion Forums

Return To The Fast Tracks Website

The Fast Tracks discussion forums have been closed. Click Here for more information.

It is currently Sun Feb 23, 2020 9:48 pm

All times are UTC - 5 hours [ DST ]




Forum locked This topic is locked, you cannot edit posts or make further replies.  [ 2 posts ] 
Author Message
 Post subject: turnout radius
PostPosted: Sun Dec 11, 2005 5:59 pm 
I am trying to find out what the radius is of turnouts. I would like to keep the "turnout" part to a 28" or 30" radius, but do not know the equivalent turnout size to get (#8 maybe?)
Tony


Top
  
 
 Post subject: Turnout Radius
PostPosted: Sun Dec 11, 2005 6:49 pm 
Offline
User avatar

Joined: Sat Aug 13, 2005 10:48 am
Posts: 365
Location: East Texas - USA
Turnouts don't have a simple radius. (At least not the real ones). Some manufacturers do use a radius - but proper turnout geometry will have straight frogs at an angle (1:4, 1:5, 1:6, 1:7, etc.) and the switch points will be straight for their movement toe to heal and offset at an angle (usually about 1:20). The divering closure radius is a product of alignment with the straight frog and the straight switch points.

There is 'equivelent' radius that includes the frog and switch rails (for fitting into a curve), but the real radius of the curved rails is sharper.

Check the actual NMRA RP12.x series of turnout dimensions and data since the FastTracks templates are constructed to these specifications.

http://www.nmra.org/standards/consist.html#standards

Is your concern and 'equivelent' radius or a 'minimum' radius?

As and example: HO Number 6 (NMRA RP-12.3) -
Closure Rail Radius - 43" (note the number 5 is only about 26")

There are some 'usual quidelines' for turnouts - but each specific manufacturer and template will be unique - and all will have to be fitted in place and adjustments to the track leads made.

For FastTracks construction - you can download and print the tie templates and fit the one you want to meet your right-O-way needs.

Curving trunouts will be a different set of principles - generally you get a smoother and gentler curve - but at the cost of carefull hand construction and/or adjustments. (Download the twistties manual and see how the curved construction progresses). Also, Tim just released an alternative method for curved turnouts in his latest news release.

_________________
-ed mccamey-
COSLAR RR - http://www.coslar.us/
NMRA Standards and Conformance Department
PROTO & FINE Scale Coordinator
I estimate I have about 5 pounds of coupler springs somewhere in the vicinity of my workbench.


Top
 Profile  
 
Display posts from previous:  Sort by  
Forum locked This topic is locked, you cannot edit posts or make further replies.  [ 2 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group