Looking at what WebOCalc is teaching us
Ok, let's go back and compare the results. We'll look at the specs when we use a 730 kV motor, and the specs when we use an 890 kV motor in our Super Cub example plane.
Using a 730 kV:
Prop: APC 10x7SF -- Top speed 39 mph -- 29 ounces of thrust -- 12 amps of current.
Using an 890 kV motor:
Prop: APC 10x7 TE -- Top speed 48 mph -- 28 ounces of thrust -- 14.6 amps of current.
We can see that my little 14 amp 890 kV motor will work fine. It'll be a faster plane, but still very close to the 3 times stall speed we usually aim for. It will develop about 1 ounce less of thrust, which is still fairly good thrust. But it will be pulling about 20% more juice from my battery.
WebOCalc shows us that we are paying a slight penalty for using a higher rated kV than what is ideal. And WOC is showing us that for this 14 amp 890 kV motor, our best bet will be the APC 10x7 TE prop. In other words it picked a prop that will maximize my equipment...
Now, I have one of these Super Cubs, and I used WebOCalc to help me pick the right motor and prop for it. It works verrrry nicely with the prop WebOCalc picked.