<div style="margin-bottom: 0cm"><span style="font-size: medium">Discussion of these Results:</span></div><div style="margin-bottom: 0cm">1. The results showed this motor has a Kv of around 2190 RPM/V, slightly lower than the HKcalculatedKv of 2250 RPM/V -but not by much.</div><div style="margin-bottom: 0cm">We can see very easily that the Kv of this motor must be lower than 2250, from the No-Load testing. The motor had an RPM of 25650 when driven by 12.36V. If the Kv was 2250, then the No-Load RPM would have been about 27810 (i.e. 12.36V x 2250 RPM/V).</div><div style="margin-bottom: 0cm">-However, Kv is only a theoretical value, calculated as if the motor is perfect with no losses, and is operating under a completely zero load. In reality, all electric motors have some load (even under no-external load conditions), and all brushless motors have some losses due to voltage drop across Rm and also due to thermal losses. The "real world no load speed" is probably a more practical value, and was calculated by DriveCalc as 2138 RPM/V (about 100 less than HKquoted Kv of 2250 RPM/V).</div><div style="margin-bottom: 0cm">
2. The No-Load current for this motor was0.38 to 0.53A, depending on voltage. The Rm / Rd was found to be about 331 / 337 milliohms, close to the HKquoted figure.</div><div style="margin-bottom: 0cm">
3. <span style="font-size: medium">The most striking feature of this motor test, is that NONE of the props tested, from 4" to 8" diameter, produced a current less than 4A -which is the max current quotedon HKspecs...!</span></div><div style="margin-bottom: 0cm">The prop which gave lowest current was the GWS 5x3 on 2S LiPo, and even this prop generated a current of 4.7A. It produced an input power of 36W, which is right at the top of theHK rating.</div><div style="margin-bottom: 0cm">It is possible that the rating given by HobbyKing is very conservative, and that in reality this motor can take much larger currents than 4A. It may be that the current / power rating will have to be revised in future, with perhaps something like 7A being a sensible max current for this motor (which, with 2S LiPo, would be a max power of ~50W i.e. 7.4V x 7A).</div><div style="margin-bottom: 0cm">
4. Despite input currents larger than 4A, this motor continued to perform, and was clearly able to handle much larger currents than 4A. It even handled currents between 9 and 12.6A, when generated by the largest props -however these props were probably overloading the motor.</div><div style="margin-bottom: 0cm">The motor certainly seemed to be able to handle currents of 5A and 6A, at least. The GWS 6x3 prop (on 2S LiPo) gave a thrust of 236g, whilst drawing 6.6A, and for an input power of about 50W. This appeared to be near optimum performance for this motor.
<div style="margin-bottom: 0cm">5. It seems clear that the 3 largest props overloaded this motor -judging by the fact their g/W values were very low, and their efficiency values were 50% and below. These larger props also drew currents of more than 9A. Therefore, it would seem that props larger than 6x5 cannot be recommended for this motor.</div></div>