There is a spreadsheet available with test data from over 251 unique propellers frequently used on rc model airplanes. Dr Phil Millener, Chattanooga, Tennessee (RCGroups.com user “Dr Kiwi”) has compiled a massive amount of data on almost all the frequently used RC propellers, and gave us permission to make the file available to you for download. For your convenience, there is also a reformatted version which only contains the results without any macros (available in .xls format and .csv format.)
This spreadsheet has over 13000 data points for different propellers. Each row has the following information:
- Propeller Name
- Motor Used
- Propeller Diameter
- Propeller Pitch
- Amps, Volts and Watts drawn
- RPM as % of Kv * V
- Motor Weight
- Motor and Gearbox weight
- Thrust (in g and oz)
- Grams per Watt
- Pitch Speed
There are macros in the spreadsheet. You can either use them to produce graphs and sort data, or disable them and just read the data. From this data, you can make a more educated choice on which propeller is best for your application. Looking at figures, such as the number of grams per watt obtained, can help you choose between similar propellers by giving you an estimate of which ones are more efficient in different situations. Depending on if you’re building a quad copter for hovering and aerial photography or a high performance RC airplane, you can now get an objective picture of the differences between the propellers.
Simulating propeller performance is a difficult thing to do, and usually requires the use of approximations and assumptions that reduce the accuracy of the final results. Having actual experimental measurements overcomes all of these problems. Individual measurements are usually hard to find online, and are typically scattered among different sources. Besides being difficult to locate, you can’t usually compare similar propellers side by side, since each tests lists data differently. This spreadsheet is a big step towards solving this problem.
Here’s some sample data, taken for an APC 8×6 E Thin Electric Propeller with a Hacker A20-22L brushless motor:
If you wanted to know how this propeller performs with this motor as RPM is increased, you could make a plot like this in Excel (or any other spreadsheet program, like Numbers, if you’re using a Mac.)
Adding a trendline to the data allows you to make a prediction about the thrust this propeller and motor would provide at other RPM values. A simple polynomial fits the measured data well, and since there are more than 3 data points, you can be reasonably confident that the predictions will be good.
Another useful quantity could be the efficiency of the propeller and motor in grams of thrust produced per watt of power used. Here is one such plot.
APC RC model airplane propellers are available on our website, along with suggested brushless motors.