Hi all,. Good weather, off work, new tablet , batteries all charged but I go to put radio controller together and what is probably a somewhat smallish threaded nut type piece is missing. The one that holds the piece that clamps the tablet to the rest of the controller has nothing holding it in the slide just the male threaded piece . Called 3DR and not open , hoping it's a holiday thing but where can I get another one if they never answer ? THANKS