SeaComms
04-30-2008, 06:16 PM
Howdy all, just had to replace the tail rotor shaft and came across a very interesting problem that I heard someone else mention a while ago.
Firstly it was damn hard to remove the 'head' off the shaft, as they had loctited the grub screw in and the loctite had seeped into the join between the head and the shaft.
Anyway, got that off, then had to remove all traces of the loctite off the shaft to be able to remove the shaft through the bearings.
Thats done, installed new shaft, secured head to the shaft and reassembled.
All seemed good, was fiddling with the pitch slider to make sure everything was moving smoothly and noticed when its brought in against the body it sticks there and does not want to move out on its own, it required the blades to be manually rotated to get it moving.
Closer inspection showed that the head has about a 2 mm area where it can be secured on the shaft. I had mine perfectly flush with the end of the shaft. I had to move it about 1/2 mm in toward the body before it would no longer stick.
If you look at the design, as the slider moves closer to the body the links to the blade grips get closer to being inline with the blade grips (bit hard to explain). With the head being too far out on the shaft, they will actually line up and cause it to stick in place.
If this happened during flight, you would end up stuck on full throw and possibly burn out a servo when it was trying to correct itself.
Firstly it was damn hard to remove the 'head' off the shaft, as they had loctited the grub screw in and the loctite had seeped into the join between the head and the shaft.
Anyway, got that off, then had to remove all traces of the loctite off the shaft to be able to remove the shaft through the bearings.
Thats done, installed new shaft, secured head to the shaft and reassembled.
All seemed good, was fiddling with the pitch slider to make sure everything was moving smoothly and noticed when its brought in against the body it sticks there and does not want to move out on its own, it required the blades to be manually rotated to get it moving.
Closer inspection showed that the head has about a 2 mm area where it can be secured on the shaft. I had mine perfectly flush with the end of the shaft. I had to move it about 1/2 mm in toward the body before it would no longer stick.
If you look at the design, as the slider moves closer to the body the links to the blade grips get closer to being inline with the blade grips (bit hard to explain). With the head being too far out on the shaft, they will actually line up and cause it to stick in place.
If this happened during flight, you would end up stuck on full throw and possibly burn out a servo when it was trying to correct itself.