Discussions

For the FPV and multicopter industry to accelerate it's annual leaps in technology, it is my belief that it needs standardized test procedures so that:

- a manufacturer/inventor knows

  ... before product launch how their product compares (saving money and helping focus research)

  ... which product is best so they can tear it down and improve up it

  ... receive royalties when protected products are copied, helping pay for further research

- the consumer can

  ... properly reward companies that produce the best by buying their products

  ... more easily build/buy optimal ships

To my knowledge there are four common technical criteria for a multicopter rotor (as opposed to an airplane that because of wing lift has slightly different test criteria):

1) Maximum Net-Lift--This is how much more the rotor can lift after it lifts itself. Until it lifts itself, it is doing nothing except vibrating the ship. Max Net-Lift is critical because in design one wants a minimum lift margin of 2X or 3X hover.  Max Net-Lift thereby becomes a decision gate. One only needs to consider rotors that exceed design needs.

2) Net-Lift Efficiency--How efficiently a rotor lifts the ship and payload that in the end determines how long the ship will stay in the air. For an FPV racer, this criteria is not very important as the ship only needs to stay in the air less than 2 minutes. But a camera, inspection, or sensor multicopter needs to stay airborne for 15 minutes to 3 hours to be useful. This is a criteria with degrees of benefit.

3) Response--How quickly the rotors can achieve a commanded change in thrust. This is a criteria with degrees of benefit. This greatly impacts:

   ... Acceleration (critical for off-the line starts, changes in direction, etc. while FPV racing)

   ... Stability in apparent wind (critical for any kind of flight)

   ... Control of off-center payloads (critical for camera, inspection, and sensor ships)

   ... Smoothness of camera/sensor platform

4) Maintenance Schedule--If the maintenance schedule is defined and valid. How often bearings and other components need to be changed or checked. This is critical on ships carrying expensive payloads. This is a decision gate criteria.

There is, of course, one other non-technical criteria, cost, that is impacted by the maintenance schedule (durability of the ship). And there are other technical criteria, but not always common between applications (e.g., noise, vibration).

These links are to video of draft standardized test procedures. I'd like to collect input and collaborate with other test labs on defining industry-wide standardized tests useful to our industry.

Efficiency - https://www.youtube.com/watch?v=6EGwVhoqEz0

Response - https://youtu.be/aw3cCJwSn38

If buyers use the data from the test labs and manufacturers know it, then and only then will the industry become more serious in narrowing choices to "good" choices for consumers and integrators that build ships using off-the-shelf rotor components. For this to work, lab data needs to be:

- known by the consumer (which quickly informs manufacturers)

- easy to access (e.g., Consumers Reports, Consumers Research, JDPower, etc.) through multicopter forums.

Data results might take the following forms.

Net-Lift Efficiency - Maybe a chart showing the full range of net-lift efficiencies comparing different rotors along with a bar chart that summarizes to a single average of the middle 40% of the thrust curve.

Response - Maybe a table showing how much of targeted thrust is achieved at various Hz rates or just a single number denoting the Hz rate where 80% of the commanded target thrust delta is met.

Maximum Net-Lift - Maybe a Bar Chart showing side by side comparisons. 

Scope: These tests would only apply to rotors: ESC, Motor, Prop combinations.

Any way ... your thoughts please. Is this needed? Would people use it? What tests are needed for component selection? Are these tests valid?