zenmetsu
Member
Since I figured that I have about 50 hours on my bird, I decided to tear it down completely and do some preventative maintenance. This was partially spurred by the fact that I got a new tail gear housing (the align part) to replace my EXI housing. Now I can finally use all Align replacement parts without fear of compatibility problems.
Also, last night I spun the heli around and put the tail right into a large hibiscus, but she stayed in the air. I noticed an immediate change in sound, however. It sounded like the dreaded 250 tail wag but a little slower and the tail was still holding rock solid. During my teardown, I noticed that the belt was failing. The teeth were all still there, but some places were stretchy now, indicating that the kevlar belt had failed.
As for the overhaul, my motor is still going strong so I left it alone. I do not know the average lifespan of these motors, but I gave the bearings some lovin'. I replaced the two main shaft bearings, and gave everything else a good cleaning. I replaced the tail gear housing with the plastic Align one. I wish that they had an aluminum part, however, since this part is one of two that keep the upper and lower frames together. The tail drive shaft did not seem to spin as freely as I would like, but I gave it some lube in the hopes that it would loosen up.
I gave all my bearings and screws a good soaking in acetone, flushed the bearings with lubricant until they were clean, and put everything back together with some blue loctite. I replaced the dampers in the rotor housing. After a few hours of letting the loctite up, I spooled up the heli indoors. Holy cow... it was like a new bird. The noise was probably 30% what it used to be. The pulsing from the belt was also eliminated, as expected. I also noticed that she took slightly less power to hover now, probably because the motor was not straining as much.
I took it outside and fell in love this this heli all over again. I don't know what it was, the dampers or the mainshaft bearings, but this thing has almost no vibration now. I have the gyro gain at 70% now in HH mode, up from 66%, and I cannot get it to wag no matter how hard I try to piro the thing.
All I gotta say is thanks to the input from people on these forums and keep your helis maintained. I am fairly certain that the main shaft bearings had a lot to do with this since they were a bit notchy.
Also, last night I spun the heli around and put the tail right into a large hibiscus, but she stayed in the air. I noticed an immediate change in sound, however. It sounded like the dreaded 250 tail wag but a little slower and the tail was still holding rock solid. During my teardown, I noticed that the belt was failing. The teeth were all still there, but some places were stretchy now, indicating that the kevlar belt had failed.
As for the overhaul, my motor is still going strong so I left it alone. I do not know the average lifespan of these motors, but I gave the bearings some lovin'. I replaced the two main shaft bearings, and gave everything else a good cleaning. I replaced the tail gear housing with the plastic Align one. I wish that they had an aluminum part, however, since this part is one of two that keep the upper and lower frames together. The tail drive shaft did not seem to spin as freely as I would like, but I gave it some lube in the hopes that it would loosen up.
I gave all my bearings and screws a good soaking in acetone, flushed the bearings with lubricant until they were clean, and put everything back together with some blue loctite. I replaced the dampers in the rotor housing. After a few hours of letting the loctite up, I spooled up the heli indoors. Holy cow... it was like a new bird. The noise was probably 30% what it used to be. The pulsing from the belt was also eliminated, as expected. I also noticed that she took slightly less power to hover now, probably because the motor was not straining as much.
I took it outside and fell in love this this heli all over again. I don't know what it was, the dampers or the mainshaft bearings, but this thing has almost no vibration now. I have the gyro gain at 70% now in HH mode, up from 66%, and I cannot get it to wag no matter how hard I try to piro the thing.

All I gotta say is thanks to the input from people on these forums and keep your helis maintained. I am fairly certain that the main shaft bearings had a lot to do with this since they were a bit notchy.