Frequently people report tail blade bearings giving up on the ECO. The result can be dramatic. When you loose the tail, the only way to get the helicopter down safely is to cut the throttle and try to autorotate. Not an easy maneuvre when you are a novice or very close to the ground.
Here's a picture of what it looks like when a bearing gives up
So, what can be done about this?
The best method is to add thrust bearings in the tail as the reason why the radial bearings give up as that the axial forces are higher than what they are designed for. Boca bearings sells a 2x6x3 thust bearing that's perfect for the task. Their product number is F2-6-43. It's the top one on this page. You will need a 12mm M2 bolt to mount the tail tail blade holders. Do not use aluminium screws in the tail. Use steel ones and if possible stainless or hardened steel.
Slide the thust bearing on the screw, then the radial bearing and finally the tail blade grip. Put some thread lock on the screw and have it bottom out on the tail shaft.
Note
Even with these thrust bearings it's advisable to check the tail bearings every 20 flights. Replace them if ever in any doubt. The radial bairings are very cheap and not worth losing a helicopter over.
Also take into account that tail blade screws can fail. When ever your tail hits the ground hard enough replace the screws!
