Next, I compared all of the tests against each other. The following looks at the wattage (power) needed to hover for each prop at different weights.
The following looks at the efficiency. For this specific build, tri-blade props of a lower pitch were the most efficient. This is likely because the 1206 motor is powerful enough not to be affected by the extra torque required to spin tri-blade props versus bi-blade, at a hover. So having an easier to spin bi-blade with less thrust just results in the motors needing to spin faster to get the same trust as the tri-blade, which can be seen in Figure 3.
Below clearly shows the throttle value needed to hover for different props at different weights.
Figure 4 shows data collected from looking at Tattu Ace battery specifications. It can be seen that the specific energy, Wh/gram, is fairly consistent across the Tattu Ace line, making it a good battery for using as a base to extrapolate new information from.
The following graph, Figure 5, was made by using:
- The wattage trends of the Emax 3024×3 props as shown in Figure 1.
- The battery trends, weight and Wh, shown in Figure 4.
- And a utilization constant of 75%, to represent a healthy discharge.
- A quad dry weight of 135g
In Figure 6 below, the same process was used as was used in Figure 5, but with added dead weight to represent a payload. The added payload could be extra cameras, GPS, buzzers, or anything imaginable.
One interesting trend that can be seen is that as the battery size and weight increase the flight time plateau begins to look more linear. Meaning as the energy complicity increases and the overall weight also increases, adding weight begins to have a less dramatic impact on flight time. However as the overall weight increases the motors are likely to run hotter, the quad will be louder, and the quad will feel more sluggish flying. The red line has been drawn to show the battery capacity needed to hover for 6 minutes with a given payload. The time was chosen as a threshold for a decent hover time for an FPV quad.
I started doing these tests in November of 2019, but due to becoming busy with other things posting was delayed. In that time, iFlight has discontinued the XING Nano 1206 motors. My guess is that the motors, while very powerful for their class (9*9 mounting, likely toothpick style) they lost some efficiency.
The motors fit in the market would likely be for a pilot that needs to make very rapid changes in motion, acceleration. Since if the pilot is flying smoother it is likely that the pilot would not notice a difference if they were using a slightly smaller and more efficient motor such as a 1204.
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Copyright © 2020 by Gregory Gutmann