RE: Hovering aerodynamics
HI COMBATPIGG: A practical tailstander VTO/landing model is a challenging project. I built a ukie tailstander many years ago with a throttle controlled .29, and found that while vertical takeoffs were easy, vertical landings were anything but. The main design weakness of my model was its conventional layout, resulting in its CG being a bit high above its bouncy landing legs, resulting in unpretty tipovers upon most landings.
My R/C tailstander design (not yet built) uses a tractor canard layout, to get the CG closer to the ground in vertical attitude, while the wingtips conveniently provide two of the needed widely-spaced landing support legs. A high vertical fin/rudder assembly provides the other point of attachment for a landing leg, with a retractible strut under the fuselage supplying the fourth. Each landing strut incorporates spring/shock assemblies stolen from model cars, since tail-sitting landings can be a bit rough.
A pusher canard with a bit of wing sweepback also appears attractive, but the prop is very close to the ground and a lot of dirt would be kicked up and ingested by the engine, so it would need a good air filter, and also probably an auxiliary cooling fan - pusher engines are notoriously hard to cool. Canards fly pretty much like tractors, and I want my tailstander to perform well in normal flight, and not become a one-dimensional oddity. A swept-back tractor flying wing layout also looks feasible.
The lower strut is retractible so that dead-stick landings can be done simply by skidding the model in on its belly or on plug-in conventional gear.
Engine overheating can afflict conventional layout models during prolonged hover - I usually limit hover duration to about 20 seconds. I selected a ducted fan .80 for prolonged hovering since a large head with plently of cooling fin area is available for it. Would love to hear how you make out with your tailstander.