Raven's Major Ground Maintenance

2009-02-24 Tuesday

In my last flight (FID:H3.E2.G2.T6.2 2009-02-22:1145) I was having problem with the nut which holding the tail blade pitch slider.

Fixing Tail pitch Slider
I was thinking to put the 'red loctite' to make sure it will hold forever. However due to limited time I have, I decided to fix it with my existing Blue Threadlock.

From Remote Control Helicopter - 2009

Note: Blue Loctite or thread-lock is a removable thread lock, can be removed with normal hand tool. Using Red Loctite, it will be much more firm, to remove it will require application of heat or special chemical. "Loctite" itself is a popular brand for such products, there are other brands but people still calling these as 'loctite'.


Fixed, yet to fully test it..

From Remote Control Helicopter - 2009

Fixing Main Gear
I had been flying with missing tooth and some uneven teeth at the main gear. I decided that this is the time to change the main gear. If I hold it much longer, other problem can be introduced by this small issue especially when it become more severe.

From Remote Control Helicopter - 2009

After opening the canopy and inspected the main gear, I was very shocked! Noticed that the bolt which is holding the main shaft has came out half way. It was really a 'near disaster' situation! After I taken out the bolt and inspected it closely, realized that has been broken.




This could also be resulted from the main gear issue. It has caused lots of vibration and impacting other parts of the chopper.

Replacing the Main Gear should be straight forward due to very good and maintenance friendly design for the Century Raven Helicopter. It should only involve 4 screws, 3 at the coller and 1 which already broken and taken out.

I started to dismantle the linkages for swash plate. However, I had problem with one of the screw holding collar for the shaft. Tried to pull out the main shaft however it wont move at all. Tried knocking it from below, the result still the same. I managed to move it a bit, the main gear slide about 3 mm, but that was not good enough.

So this will not be that easy as what I expected.

Both Sides of Upper Frame is Broken
Then I noticed that the upper frame has actually broken!! I can't really understand why or when it broke. I think it must be due last bad crash I had (about 2 month ago). The crash must have created some crack or internal structure damage to the upper frame (the lower frame was badly dented), and continued flying with it resulted into fatigue, failure and broke. It was quite disappointing, however I figured that it should be minor issue since the broken part was at the bottom of the frame where it will be tightly held by lower frame.

I continued the next day (well, night actually) still not able to remove the collar or the main shaft. Next thing to try is to split the upper frame and take out the main shaft from the side. That will be MAJOR work.

To avoid the major work of splitting the frame, I decided to get help from Cikgu Vanan, the Century Raven distributor in Malaysia.

2009-02-27 Friday

I went to Cikgu Vanan's place, reached there about 8.45pm. After few minutes evaluating 'the situation' his solution is also to split the frame! Well at least I confirmed it with the expert.

So I have the Raven's upper frame dismanteled, removed all od the servos, separated the servo/battery, taken out the rotor head assembly from the main shaft.

With the shaft out from the frame, the main gear easly slides out from it. Using the heat gun at the collar, the stubborn screw finally can be removed.

He also kind enough to give me the right side of the upper frame for free and applied epoxy glue to the other side to fix the broken part. He also given me some screws to replace my exisiting damage/bent/broken screws.

From Remote Control Helicopter - 2009

Reached home at about 1159 pm, without the need to pay him a single cent! Thank you Cikgu Vanan.

Off course, I will need to assemble and test it myself!

From Remote Control Helicopter - 2009