We’re big fans of creating crazy click-bait titles – and the title for this post is no exception. Sure, bacon has nothing to do with drones whatsoever but at least you know that this wasn’t written by ChatGPT.
Yet perhaps this title isn’t as crazy or click-bait-y as it first appears. First, bacon is tasty. That’s a scientific fact. Second, if you froze many slices of bacon together in a horizontal position with particular folds – like a sheet of paper folded into a paper airplane – it would be quite aerodynamic and perhaps capable of flight.
But, alas, unlike anvils, we haven’t found anyone who has posted a YouTube video showing how they tried to make bacon fly (which we think is another sign that humanity is in steep decline).
Right. So let’s go back to the aerodynamics of drones. Or rather the lack thereof.
You’ll recall from the excellent article entitled The Problem with Skinny Propellers that there is a trade-off between the efficiency of the electric motor and the speed at which the propeller could still achieve laminar flow.
Generally speaking, the peak efficiency of the small electric motors used in drones is well north of 10,000 RPMs and that means you should use a skinny propeller to avoid as long as possible the transition from good laminar flow (which creates lift) to turbulent flow (which creates drag and diminishes lift). But not even a skinny propeller can hit even close to 10,000 RPMs. Most top out at about 5,000 RPMs. And that means the electric motor is operating very inefficiently.
Why is that?
This is because electric motors have a peak efficiency point, which is tends to be around 75-80% of its maximum speed and as you’ve guessed operating the electric motor closer to this peak efficiency point results in higher efficiency. The key here is this: at lower speeds, the electric motor will likely draw more current to produce the required torque and that can lead to higher losses due to increased resistance in the windings, increased temperature (which causes even more resistance), etc.
Check out the nifty graph below for you visual types.
So because the electric motor in most drones is operating at a lower inefficient RPM and is at the same time forcing the skinny propeller to operate at high RPMs, this all means lower flight times.
Except if you fly a Modovolo Lift, where through the magic of first principles engineering, the electric motor operates at its peak efficiency of 20,000 RPMs and the beefy propeller spins at its peak efficiency of 1,000 RPMs. And that means much longer flight times.
You can pre-order your Modovolo Lift here. Only 200 pre-orders available.
