Hi -- Very interesting! I can verify the numbers from empirical results. Not quite by accident, but from experience, I settled on 54” minimum radius to keep my bigger locos and passenger cars happy. I actually use larger wherever I am able – 72” minimum where the track will be visible (not under scenery). This is still a 15 degree curve which is quite sharp by real railroad standards... And yes, I still use easements to enhance the visual effect.
Thanks for the lesson! Bill Winans Prescott Valley, AZ From: Ab Baird Sent: Tuesday, February 08, 2011 7:34 PM To: [email protected] Subject: {S-Scale List} easement curves At last. Something I know about. An easement spiral should be, at minimum, as long as the longest car you plan to run. The radius of the curve together with the length of the spiral determines the offset required. The offset equals the length of the spiral squared divided by 24 times the radius. To go the other way, a curve of 30 inch radius with a 3/4 inch offset requires a spiral length of 23.25 inches. ... Since a 72 ft car is 13 1/2 inches in S gauge, the spiral is longer than we need. A 13 1/2 inch spiral with a 30 inch radius curve would require on offset of 1/4 inch. But 30 inches corresponds to a 35 degree curve which is sharper than NMRA standards for a 70 ft car with diaphragms. The recommended curve is 30 degrees or 36 inch radius. ... If you want 80 ft cars the recommended minimum radius is 25 degrees or 43 1/2 inches, for 85 ft cars it is 20 degrees and 54 inches. Ab Baird(Canadiannorthernhistorian) ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/S-Scale/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/S-Scale/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
