Aircraft And Helicopter Calculators

One of the tricky parts of electric flight is choosing the right components for a new plane or helicopter. How do you know which motor to pair with which speed controller? What size propeller will give enough thrust without drawing too many amps? And what battery is going to be up to the task?





The problem of matching all of the pieces is further complicated by the fact that there is no one right answer for a particular plane. The electronics that are right for you may not provide enough power for a more advanced pilot, or may not fit in someone else's budget. Maybe you already own a motor and need to build a system around it. What to do? Fortunately there a number of calculators out there which will help you run the numbers and try out different combinations. Most of them are free and run in a web browser, while a few run on your PC. A good place to start is P-CALC by Diversity Model Aircraft. It has a very large collection of motors already programmed in. You can also specify a custom motor if you wish. There aren't too many options, so it shouldn't be overwhelming for new users.





Another powerful airplane calculator is the Motor & Prop Calculator by Adam One. It displays Imperial and metric units simultaneously, and one updates when you change the other. You can even enter temperature, altitude, and barometric pressure if you want to see what effect they have. The only thing which doesn't seem to work is the graphing feature, which I tried on Safari and Firefox. Perhaps it only works in Internet Explorer, or not at all. Not to be outdone, a well-named site called Flies Like A Beagle has two airplane calculators available. Click on Software in the left column, and then try WebOCalc and PowerCalc at the top. Both are available while you're online in a browser, or can be downloaded and run offline in your browser. Either way you get the same programs, and they can be run on any computer. I like the WebOCalc feature which tells you how a particular setup will fly in plain English, from "mild trainer" to "outstanding 3D". That leads me to MotoCalc , perhaps the mother of all flight calculators. This is a commercial application priced at $39 USD, with a free 30 day trial. The list of features is a mile long, including setup comparisons, graphing, and an export to spreadsheet function. MotoCalc is a desktop app for Windows, and doesn't have a Macintosh version. It has a long history and receives constant updates, including its data files (specs for motors, ESCs, etc.), which are the most complete of any tool here by a large margin. Lastly, Dark Horse RC has an impressive Helicopter Power & Setup Calculator available for free. You can enter values by hand or use the buttons at the bottom to drop in preset values for some of the most popular helis. If that's not enough, you can also try the beta version of his Advanced Calculator , which offers many more choices and controls. Flight calculators are very helpful tools, and there are lots to choose from. Remember that these programs can only come up with estimates, so don't count on drawing exactly 24.5 amps on your 25 amp speed control, just because the software told you to. However they are very useful to try out different combinations of gear without buying the equipment first.