Is there an existing thread or forum for this?
I have been working on charting the 2806.5 1300 KV,
applying some knowhow of Kv and Kt (si units)
It looks like the test benchmark is really misleading.
It shows 48 A, 777 W in, performing like a 9x4 prop at 16, 000 rpm.
However, it seems that real rated power is more like 356W and 22.5 A, and 0.15 N-m
The test benchmark is unsustainable, and was likely run at around 72 % rpm, where rating is at 77 % rpm- right at the possible limit!
efficiency is down to 60% and power is going vertical ballistic.
I also think the 2806 efficiency may be 85% at rated, and curve off more gently than this engine I have charts for, the 875w 1800 KV motor.
I am having real trouble nailing down the basic motor equations to model the motor behavior.
Kv, Kt, torque = Kt x A, rev = power/torque, don't seem to agree with each other. I fudged it by using 1300KV for rpm and 1000 KV for
torque calculation.
The 875w motor rates at 500 w 41 A real.
I am charting up a "gang of 4" motor for the 14 x 7 prop, so it will need a litle adjustment. At 38 amps in for each motor, it is a bit off the rated area.
It also runs at 11,000 and 14,000 rpm. which is 67% and 52% revs. the 875 will blow up below 67% !
Here is a mix-up chart. with "everything" plotted! I am trying to put these charts on a more scientific footing, but I need more motor theory, and less benchmarks!
I have been working on charting the 2806.5 1300 KV,
applying some knowhow of Kv and Kt (si units)
It looks like the test benchmark is really misleading.
It shows 48 A, 777 W in, performing like a 9x4 prop at 16, 000 rpm.
However, it seems that real rated power is more like 356W and 22.5 A, and 0.15 N-m
The test benchmark is unsustainable, and was likely run at around 72 % rpm, where rating is at 77 % rpm- right at the possible limit!
efficiency is down to 60% and power is going vertical ballistic.
I also think the 2806 efficiency may be 85% at rated, and curve off more gently than this engine I have charts for, the 875w 1800 KV motor.
I am having real trouble nailing down the basic motor equations to model the motor behavior.
Kv, Kt, torque = Kt x A, rev = power/torque, don't seem to agree with each other. I fudged it by using 1300KV for rpm and 1000 KV for
torque calculation.
The 875w motor rates at 500 w 41 A real.
I am charting up a "gang of 4" motor for the 14 x 7 prop, so it will need a litle adjustment. At 38 amps in for each motor, it is a bit off the rated area.
It also runs at 11,000 and 14,000 rpm. which is 67% and 52% revs. the 875 will blow up below 67% !
Here is a mix-up chart. with "everything" plotted! I am trying to put these charts on a more scientific footing, but I need more motor theory, and less benchmarks!
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