Mind the level of the Bed of your printer in order to print wings correctly !
Wings are a little bit hard to print du to their thickness !
Make sure the plane is well calibrate : the gravity center must be thereabouts the leading edge : "https://en.wikipedia.org/wiki/Longitudinal_static_stability" if you want to learn more about this !
The glider must weigh approximately 3g and you can adjust this value whith the filling of the glider !
Enjoy ;) !