whiplash comments
What servos are you using? the elevons are stiff, but you dont need any more than 5/16 - 1/2" throw, anymore than that and you would be surprised by the reaction.
The antenna tube is 6mm I cant understand why it would go thru, try running a 2/56 rod thru it as far as you can go.
Is this a whiplash X or an older version? we did have problems with stiff ailerons and antenna tubes with some of the older units...please advise