Sorry, tell your coach the question needs work. The only way to answer is to assume everything else is fixed and then make a whopping bunch of assumptions. And then its messy because its a messy, non-linear system that also depends on available ceiling height. The theoretical answer depends on math WAY beyond MS, and there is no good rule of thumb.2017Kortman wrote:Okay, my coach gave us some homework, and I need to know how rotor pitch affects flight time. <SNIP>
Here's a way to answer the question. Build three copters with different pitches, but same weight, same blade area, number of blades, blade shape.
Now, pick the middle pitch, and match a motor to it to make it fly reasonably good in the space you have. Once you have a good motor size for that pitch, fly the other two motors with the same motor size & winds. What's the answer?
Next, check that result by matching a motor to the lower pitch. Probably different size and winds than before. Use that motor, size and winds on the other two copters and see what happens.
Match a motor to the high pitch copter. Try on the two other copters. Result?
Was the result consistent, wherever you started?
If you don't understand what I'm saying when I say match the motor to the pitch, look back up this string.
Hope that helps,