Crashed my trex 500 esp last week!
Yep, crashed when landing. Wasn't descending fast but suddenly the ground rose up to meet me. Careless piloting!!!
Not a lot of damage, Main blades, flybar, set of gears for a DS 510 servo and a lot of hurt pride. Anyhow, it is all rebuilt now and flying.
That brings me to the point of this post. When test flying after the rebuild, I could hear a noise from the bearings, sounded like a small bird in the canopy going tweet tweet. The noise wasn't always there. If I took the heli up to about 30 feet, then quickly took of the pitch of the blades I could hear the tweet tweet. As soon as the load was back on the noise would disappear!
I changed the motor for a spare...no! not that. I changed the main bearings...no, not that. I changed the one-way bearing...no! not that. I even removed the tail boom complete and still the noise was there.
I took out the main bearings again and they seemed to be ok, very smooth to turn, not "notchy". I examined the main shaft more closely this time and there was slight discolouration of the shaft where the bottom bearing sits. I tried a new shaft in the bearing and they felt slack...maybe!
I reassembled the heli this time I put a tiny amount of locktite on the shaft for the bearing taking care not to let the stuff enter the bearing.
After the locktite had dried, I went out for a test hover and hey presto!! problem solved, no more budgie in the canopy.
Question is, what do you guys do in this situation? Do you as a matter of course locktite these bearings in place? Do you locktite any bearing that is fitted to a metal shaft or bearing housing?
If you don't use locktite what do you recommend?
I happen to have a micrometer and I measured my main shaft at 7.97mm diameter. Main shaft bearing inside diameter is 8.00mm. Any comments?