Dave, So how many people on this list besides you and me still have a slide rule, assuming you do. And then the HP Electronic Slide Rule came out at $698. Now a giveaway at trade shows has more power.
Apollo engineers figured the route to the moon using slide rules and calculators. Not exactly but when you think I have more computing power on my desk than the MIT Instrumentation Labs (The ones who developed the inertial guidance system for Apollo) did at the time it is pretty impressive we even came close and didn't float on past Mars. Carey Carey Probst Carey Probst Member, M.I.T. Educational Council S Scale, Sn3 and S High Rail/AF A well regulated militia being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed. On 7/7/2012 10:32 PM, David Heine wrote: > > Real calculators have trig and log functions. But a slide rule could > do the job to three significant figures. > > NMRA Standard S-8 Track Centers lists the scale radius and track > spacing for various classes of equipment for clearance for curves from > 0 deg (tangent) to 45 deg in 5 degree increments. A very useful > document when determining required clearances for curved track. > > http://www.nmra.org/standards/sandrp/s-8.html > > Dave Heine > > (Who’s old enough to have used a slide rule and was in college when > using a calculator in an exam was not allowed. My K&E > log-log-decitrig slide rule was Christmas present from my parents in > high school and much used for a few years.) > > *From:*[email protected] [mailto:[email protected]] *On > Behalf Of *scale S only > *Sent:* Saturday, July 07, 2012 9:55 PM > *To:* [email protected] > *Subject:* Re: {S-Scale List} Re: Basic Geometry > > > > > Hi -- > > While it is not as accurate, there is a way to almost figure out these > things in your head. For example, a 12 degree curve indicates that > there would be 30 (360 divided by 12) 100 foot segments or 3000 feet > circumference (close, not perfect) in a complete circle. Divide that > by pi (3.14159) or for rough and dirty, 3 to get the diameter – > roughly 1000 feet. Therefore, the radius is roughly 500 feet (less > because of the rounding of pi). 500 divided by 64 will give you the > REAL feet in S, or again rounding considerably, a bit less than 8 > feet or a bit less than 96 real inches. In actuality, the real > answer is a shade under 89 inches, or an error of about 10%. Still, > this method will give you an approximation for planning purposes – if > you are into that sort of thing. FYI, a 96” radius in S is close to > a 10 degree curve, considered to be a minimum radius for standard > gauge mainlines. > > I think there is also a table of these values in one of the NMRA data > sheets. > > Have fun! > > Bill Winans > > ------------------------------------ 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/
