On Tue, 11 Feb 2020 10:16:45 -0800, Bob Kuykendall wrote:

On Tuesday, February 11, 2020 at 4:33:26 AM UTC-8, Martin Gregorie
wrote:

..The one thing we both missed, though is that a good brushless motor
plus its controller will be a lighter and smaller than the equivalent
ICE piston engine driving a propeller...

Not only that, but it delivers smoother power with less vibration,
delivers it the moment it is started, requires less service
infrastructure (starting, lubrication, cooling, exhaust, etc), and can
easily be positioned for stowage. It runs cleaner and cooler and more
predictably under a wider range of conditions, and is more easily
monitored for performance and troubleshooting.

Another thing, but this probably doesn't affect us much: a brushless
motor, which all these units are, has its rpm set primarily by the rate
at which the controller switches power round its (static) field coils
and, when driving a propeller, isn't much affected by the load its
working against. Its one reason electric brushless motors are popular
with the RC and CL aerobatic crowd - the nearly constant RPM causes
airspeed on uplines and downlines to be more constant than it ever was
with IC engines.


--
Martin | martin at
Gregorie | gregorie dot org