"Right,
Every quad would pass "tennis ball test" during manouver in acro mode at least in the absence of significant aerodynamic effects. But when I saw this tread I realized that tennis ball :) would be usefull to verify how my custon stable mode…"
"works the same way a waiter with a tray of champagne glasses,
This is my JJ-copter (modded Aeroquad) doing "Tennis Ball Test":
JJ-copter Tennis Ball Test