Regarding brushless motors mine seem notchy.
By that I mean not exactly smooth running. The craft flies great but when I spin a prop by hand it spins but comes to a definate.stop with a hint of springiness if that makes.
Having no experience of brushless motors is that the way they are?
Also would a drop of light oil help or hinder?
The “notchiness” is the inner magnets interacting with the outer parts of the motor … and totally normal.
Oil not needed - the motors have sealed bearings, so (a) they have what they need and (b) the oil would never get to where it does any good.
In fact, oil will only attract dust and dirt, reduce cooling air-flow, and cause overheating (eventually).
Crikey! So good job I asked
So normal operation then. That’s put my mind at rest.
Perfectly answered, case closed.