This test is the second in a series coming down the pipe covering 2300kv motors. I'm covering both 2205 and 2204 motors and running the same range of props where possible on each. The data will all be presented in the same format, and I've developed a new standardized document template for in Google Sheets for displaying the critical information. Please give me any feedback on ways to improve it or make it the comparisons clearer. Once I've done the full bank of motors, I'll do a document sumarizing the direct comparisons.
Now on to the facts!
I significantly rewrote the RPM sensing code for this test, so the RPMs came out MUCH cleaner right out of the logger. It means I'll be able to get these test up faster with less post test cleanup to do. I also TRIPPLE checked the calibration on my load cell and it is accurate to within +- 10g. You'll understand why that's important when look at the test results. I also have started including atmospheric conditions (barometric pressure and testing temperature) in my results sheet as a frame of reference for comparing to other tests.
This test suprised me in a couple of ways. I expected the Cobras to do well, but the numbers I got were significantly higher than I expected. My initial ESC test with the Cobra 2300kv, the regression formula I used was based on the stock Turnigy thrust stand, which it turns out was quite a bit out of calibration. I went back and updated the regression with the new accurate data on that test, but since the focus of that test was the ESCs not the motor, it's wasn't critical, only the thrust numbers were off by a factor, they were still accurate relative to each other. On this test I am getting numbers that seema good bit higher than other numbers I've seen, but I checked everything over carefully and they are accurate to my test environment.
Now related this test, there is some really fascinating stuff here. I tested the KV of this motor using a KISS 30A ESC with no load, and the KV came out at 2300KV almost on the head. This motor is getting significantly higher RPM efficiency compared to almost any other motor I've tested so far by at least 5-7%. Since I now have an objective direct comparison to use against other motors on the same test equipment calibrated the same, this test gives a great idea of relative comparisons to the other motors in this test series.
Also suprising in this is that the Gemfan 5x4.5 rounded bullnose are the top dog here. More thrust at less amps even than the HQ 5x4x3GF props, which also performed very well. The Gemfan 5x4.6BN (same profile as the HQProp 5x4.5BN) have overloaded the torque capabability on almost every motor I've tested them on so far. You can see that here by the poor thrust and high amp draw compared to the Gemfan 5x4.5 rounded bullnose. The KingKong 6x4 provided a crazy amount of thrust at 1150g, but at a significant draw of 28A.
It's worth noting that these tests don't necessarily predict flight performance, as amp draw and thrust will reduce pretty dramatically under dynamic load. These resutls are mostly for comparison purposes.