

Ithaca NY
Joined Mar 2002
73 Posts

Formulas?
Hey,
I'm putting together a little formbased windows calculator to make easy use of common/useful formulas. So, post your common/useful formulas here and I'll put it in (i'll give you credit if you wish, of course). It'll mainly focus on eflight, but similar to ezone, it'll also contain useful stuff on other areas of model flight. Thanks 




Don't have the formula handy at the moment, but something to
calculate the CG would be nice... here's a link : http://www.palosrc.com/instructors/cg.htm And maybe the standard Power/Current/Voltage/Resistance thingie? (fill in two of the above, and calculate the other two or something similar) It's just ohms law, but hey, I'm lazy Hans 



canard cg would be nice. tired of doing the math.
http://www.palosrc.com/instructors/putte.PDF 



GregT,
I have included a CG calc. program. Dick Huang 


London UK
Joined Sep 2001
105 Posts

Fast electric boat calculator
Here is a simple Excel spread sheet that I put together to calculate stuff for fast electric boats. If you click on the answer boxes you can see the formulas. Most of the calculations are also relevant to E.flight.
http://annneil.supanet.com/calculator.xls Neil 


United States, NY, Spencerport
Joined Oct 2001
2,802 Posts

The 3.6 is a conversion factor. 3600 seconds/hour divided 1000 milliAmps/Amp gives 3.6, and cancels out the milliAmphour units of the battery capacity. The "time" is in seconds, so that cancels out too. All you're left with is Amps.



London UK
Joined Sep 2001
105 Posts

I am glad mkirsh1 worked that one out first. I was having trouble remembering how I arrived at 3.6.
Neil 


Ithaca NY
Joined Mar 2002
73 Posts

Alright here is a little beta version of the first module (basic electricity formulas).
If there is a mistake in a formula, or bug, you can post it here. I am serious about this program possible being unstable, I would save all my work before using it... I haven't tested it enough to make sure it wont crash so be careful I'm putting out such a simple version because I want you all to make sure everything works for me after stareing at something for a few hours you would be suprised how easy it is to miss simple mistakes. And there will be mistakes. Mistakes in formulas, actual math, input, output... you get the idea. Next I will do CG sections (both with canard and without). Again, post all questions/ comments/ suggestions/ complaints(?) here. Download from: http://24.24.30.13/efc.zip (if anyone has webspace that I could use for this, let me know running apache on my win98 box isn't a very good idea ).  README This is just a little collection of calculators to help you remember and use all the little (sometimes not so little) formulas you find yourself using while building/testing/flying your electric models. All bugs / complains / suggestions / compliments may be sent to gregt@twcny.rr.com NOTE: This software is provided "as is". That means it's free, no support is provided. also note that this is a beta version, the code should be considered 'unstable'. Save your work before running any of these programs, as I can't promise they won't crash your computer (hopefully they wont crash your airplanes). The author of this software holds no responsibility whatsoever for any damage caused by the use of this software. 



Greg
Got some more formulas for you. 