Still constructing ICON A5
The second big challenge is to refine propeller position.
When I saw my friend’s DZ ICON A5, its noise was heavy like a nitro plane.
He suggested that noise is generated when a rotating propeller in high speed closes to tailing edge of a main wing, and a share stress of the air between a propeller and the tailing edge causes pressure gradient.
He moved back the motor 20mm using spacers. He succeeded a good result. The noise was reduced significantly.