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General control line discussion => Open Forum => Topic started by: Dan Bregar on October 22, 2022, 02:06:55 PM

Title: Speed chart for different line lengths
Post by: Dan Bregar on October 22, 2022, 02:06:55 PM

Anyone have or know the whereabouts of one of the old speed charts that gives mph for different line lengths ? If I was good at math I suppose there is a formula to figure it.

Title: Re: Speed chart for different line lengths
Post by: Dave Rigotti on October 22, 2022, 02:32:55 PM

Dan,
For 1/2 mile speed run divide 1799.28 by the time in seconds for MPH.
For 1 mile speed run divide 3598.56 by time in seconds for MPH.
52.5' lines are 8 laps for 1/2 mile
60' lines are for 7 laps for 1/2 mile
70' lines are 6 laps for 1/2 mile

Title: Re: Speed chart for different line lengths
Post by: john e. holliday on October 22, 2022, 02:50:39 PM

Thesenformulas are good if you fly from a pylon.   Remember the handle to center of plane may be 60 foot but you have to add in arm length t they will get you close.  I still have my copy of a chart that was made years ago when I flew Navy carrier.  Was told then you had to be in a pylon. D>K

Title: Re: Speed chart for different line lengths
Post by: Mark Mc on October 22, 2022, 03:12:49 PM

I’ve shown this one a couple of times before.  I love old school, and this speed calculator was a pull-out in the March 1960 AeroModeller magazine issue.  I’ve compared the readings I get on this whiz-wheel to the formulas normally used, and the results are right on the dot.  Just goes to show you how accurate the old slide rules were before these new-fangled computers and cellular phones.  I printed this, cut the two wheels out, and then pasted the instructions to the backside of the speed wheel.  Then I laminated them and pinned them together for my whiz-wheel.  I later replaced the push pin with a small tack.  I kept it in my field box for a long time, but after my recent move, I don’t know just where it is.  I may have to make up a new one, using a grommet instead of a pin for the new one. 


(https://i.postimg.cc/zXVMYxpZ/Speed-calculator.jpg) (https://postimages.org/)

(https://2img.net/h/i32.photobucket.com/albums/d26/batjac/DSCN3082_zpsba11ae2a.jpg) (https://2img.net/i/fa/pbucket.gif)

(https://2img.net/h/i32.photobucket.com/albums/d26/batjac/0bcaaf0b-2fdb-4970-8fce-569bc79910be_zps6ce2dadf.jpg) (https://2img.net/i/fa/pbucket.gif)

(https://2img.net/h/i32.photobucket.com/albums/d26/batjac/DSCN3090_zpse1d66440.jpg) (https://2img.net/i/fa/pbucket.gif)

If you’re gonna go old school and fly CL, might as well go old school on your speed calculator….

Mark

Title: Re: Speed chart for different line lengths
Post by: Steve Helmick on October 23, 2022, 12:22:39 AM

I'm sure it's in the latest AMA rulebook. Oh, wait, the AMA is an R/C sport fliers organization and they aren't interested in publishing a rulebook anymore.  '' Steve

Title: Re: Speed chart for different line lengths
Post by: Dan Bregar on October 23, 2022, 11:21:58 AM

Thanks to all for your reply  :)

Title: Re: Speed chart for different line lengths
Post by: Dave Rigotti on October 24, 2022, 08:08:43 AM

This might work for you.  Accurate to within 1MPH.