If we're going down the four-way route at the outset in order to prove the concept, then we may as well optimise it aerodynamically. To do so based on 20mm alloy and tube-connectors, I've set the centre-section at 12" square and the frame at 36". At the same time propellers have been upped to 22" for while they produce less thrust than at 18", they do so more efficiently.
These proportions match both the airframe that flew in December of 2021 at a larger scale, beside the design registered as number 6145740 in June of the same year.
