Skyhopper Wing Rebuild Part 1

[@alcourtines4707]

This is why I stopped work on my Easy Riser and got a trike! .

[@alcourtines4707]

3M 5200 is marine polyurethane and it is known for not bonding to metal very well.

[@chrusion]

Holding very well for me, but I deeply scuffed the heck out of the aluminum and cleaned with acetone.

[@marc_frank]

funky looking airfoil why would one choose LE droop over reflex?

[@chrusion]

Because the NACA 43012 airfoil provides a low pitch moment coefficient vs AoA, thus a less "pitchy" response as the CoP changes with AoA. Plus it provides a higher than average Lc and lower Dc than other "less funky" airfoils. Several GA and helicopters use this airfoil. Besides, funky is scientifically irrelevant.

[@marc_frank]

@@chrusion correct but I asked something different?

[@chrusion]

Then, you'll have to explain what you mean by LE droop vs reflex and why the airfoil is funky.

[@marc_frank]

@@chrusion leading edge droop, reflex and a horizontal stabilizer are 3 methods of counteracting the pitching moment of the usual airfoils the further away from the aerodynamic center they are, the more effect they have, so the less they have to be deflected to counter the moment any deflection adds drag, so generally, the method with the furthest distance, the longest lever arm, should be preferable?! this airfoil uses LE droop, but it's not on a special planform, where the LE is further from the AC than the TE, like a Blended Wing Body, for example so why was this airfoil chosen? one with reflex might accomplish the same, while producing less added drag? seems a bit counterintuitive and unusual to me, hence why it's funky are there other considerations i don't see?

[@bmitchely]

The "Marine Polyurethane" glue tell me about it. Why did you choose it over say T-88 or other adhesives.

[@chrusion]

#1 reason: flexibility #2 reason: adhesion. T-88 and aluminum don’t bond well without a lot of surface prep and immediate application (before aluminum oxidizes). T-88 is inflexible (cures hard and rigid), something inconsistent with aerodynamic UL airframe stresses and unequal thermal expansion rates between wood and aluminum. The polyurethane used cures to the hardness of tire rubber, adheres to mild roughened and cleaned aluminum, and flexes without tearing or de-bonding.

[@bmitchely]

@@chrusion Thank You!

[@alcourtines4707]

With a trike, just unbolt the tube and slide it out! K.I.S.S.