Yes, The Raven Flew Nicely

From the last test flight, I have problem with the main blade weight which used to balanced the rotor blades. From that incident, had the vertical tail fin broken (again after I glued it).

Last Thursday, I have brought back 2 sets of new main rotor, 1 set is the normal wooden white color type and the other set is fiber reinforced main blade. All new blades are balanced from the factory, so I don't have to worry about the unbalanced blade anymore.

Here was the wooden blade before I glue and screw the handle.

From Remote Control Helicopter - 2009

I have (again) glued the broken vertical tail fin using epoxy glue.

Today, at about 10am. I brought the Raven to the Putra Heights field 1.

Have all the equipments ready. TR3703 ready for takeoff.

I has been almost 2 weeks from the last flight attempt. I was worried that it will be very difficult to start the engine or the engine will refuse to start totally.

However, starting the engine was not difficult at all. With firm connection of glow plug, the engine started right away.

From Remote Control Helicopter - 2009

Lifted off the ground. Put into hover. Did in hover flight check, all controls seems to be ok. I am using only normal flight mode this time, not idle-up mode yet.

I pushed the throttle/pitch to the max, the engine scream and the Raven climb up. It is not as fast as I expected. I realized that I have reduced the max positive pith to +9 from original +11, to make the positive and negative pitch symmetry (+9 to -9). Got advice from a friend before (an experienced rc helicopter flier), I should put the pitch as symmetry so that it will be much easier to feel the control at both side, either up-right our up-side-down.

I keep the Raven hovering within 10 feet high, just incase of any problem it will be less impact to the ground. Everything just looks good. I continue with forward flight, to my right hand side. Suddeny I saw something dropped from the Raven. I was actually the broken part from the vertical tail fin. I did noticed that the part was not firm enough just before the take off. And just now during the flight, due to vibration, that part has dropped off.

Anyway, I continued to fly the Raven, brought it nearer to me, made it descend for landing. Huh, I have reducedback the throttle control too much and the decent rate was quit high, I pushed it up to stop the descend, but it was too late, the Raven hit the ground, a bit hard and bounced back to the air, luckily with no damage. What I afraid off is the tail rotor, no more protection since the vertical fin already fell off. I quickly bring the Raven to land and put the throttle to idle position.

Huh, what a day!

From Remote Control Helicopter - 2009

From Remote Control Helicopter - 2009

As you can see from the photo above, there is quite a mark on the ground just below the tail rotor, indicating that the tail rotor has touched the ground!!

I need to get this fix properly than only I am comfortable to fly the Raven again. I do not want to have a simple issue like this causing lots more problem.

Smile :)

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Another Night Flight Test

Sorry that I have not updated this blog for more than a week.

Many things unrelated to Raven/RC Helicopter happened (in my mind), I have been doing lots of thinking and searching.

Anyway, here is the story continued..

Last Sunday 15-March, I spent some times, did the balancing for the main rotor blade. Since I did not have the special tool to do it, I have to improvise. Screwed the 2 blades together at each end, and balanced it by only holding at the screw.

It took quite some weight to make it balance. First I tried with stickers, but they are just too small and light. Then I use a small card board paper (quite thin one). I stick it at about 1 cm at the end of the blade with a normal salotape.

At the midnight (yeah, I don't think I will have time on Monday..) I went out the the previous place to test it. It was about 12:15am. The green thingy on the blade was the 'weight' to make it balanced with the other side.

From Remote Control Helicopter - 2009

With all equipment put in place, ready to start the engine. Hmm.. my glow plug is broken again (the one I glued with super glue before).

Yes, the engine started ok. All controls are ok. Started to spool up the rotor faster and faster.

From Remote Control Helicopter - 2009

However, even when I pushed the throttle almost to the max, the blade did not seems to spin fast enough. Tried this several time, playing with the throttle, I can hear the engine screaming, indicating good response, but not the main rotor blade!

Shutdown the engine. Quickly I noticed that the metal gear on the top of counter shaft is loose again!! This was the reason why I crashed during inverted for 2 times, and now gear has gone loose again.

I tighten it up and ready for another test.

Started engine again. This time I saw the main rotor spinning up fast quickly responding to my throttle input. Yes, good!! Play with the throttle a bit to make sure it was really ok.

Suddenly, buuuhhhh! Saw something flying very fast, came out from the Raven, directly perpendicular to me, to my left!! The Raven vibrated rigorously, and I was in panic situation. And after flipping 2 wrong switches at the controller, I got the correct switch to shutdown the engine!

What happened?? It was the weight on the blade. It has ripped the white cover of the blade and got loose!! Luckly it did not went towards me or other person around. As the result as well, I have the vertical tail fin broken again. The broken part has stuck into the ground firmly, due to the force of vibration.

From Remote Control Helicopter - 2009

I was worry that the tail blade of its gear may have been damage/loose, however so far everything just looks fine.

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TV9 Nasi Lemak & Kopi O

Thanks to aerobrain for all superb photos!

Early morning Saturday 14-March 2009, when I woke up, I was still asking myself, whether I should participate or just skipped it. The Raven, from last night test, was not be able to fly. However, I kind of have arranged and promised few person that I will be there. So I should go.

Left home at about 7:20, picked up my brother at Bukit Jelutong at 7:36, reached Sri Pentas just before 8:00. We are allowed to enter and park at the VIP parking spot!

Brother Haidar, brother Mokhtar and his sons already reached earlier. Later, Sifu Zul, Zappy and Kelso arrived. I thought there will be more fliers but there was only us.



I quickly brought out the Raven to the provided space. Since the live program was planned at 9.15 or so, I should have enough time to fix the Raven issue.

Quickly I detached the upper frame, found that the fan is realy loose. Tighten up the nut. The Raven has another problem, the left frame is actully dented as well, and have not done anything to fix it. Attempting to reduce any problem resulted from this dent, I changed the spacer under the skid to thicker one. I actually using the original blade grip damper with longer screw to fix this.

X

Put together the Raven and it was almost 9.00.

While waiting for the program I decided to test if the Raven can fly. Yes, till the very last minute, I still do not want to give up!

Prepared the equipments, started the engined ok.



While spooling up the main rotor, I saw the Raven vibrated, quite rigorously. It was really not suitable for take off. Furthermore, I noticed that even I have pushed the throttle quite high, the Raven did not indicate that it have the lift for the take off. With this findings, I aborted the take off and shutdown the engine. This must have been caused by unbalanced blade. I am using a 'reused' blade given by Cikgu for free, and I did not do any balancing at all.

Brought it back to the provided table for session. With no other choice, I will be at the table with the Raven during the live program.

"Live on air" started at about 9.40 lasted about 8.5 minutes.







Inverted flight showed by brother Mokhtar's son.

From Other Photographer

Here is the 'lead photographer' aerobrain:


What a very pleasant experience. Thanks to all who has contributed to this!

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Testing Raven for TV9 Live Coverage

It was 21:30 I am still in office! I need to quickly wrap up what ever I am doing. I have 'big' event which I don't want miss on the next day. The event is live coverage of Radio Control Helicopter hobby for the "Nasi Lemak & Kopi O" program. (directly translated to "Coconut Milk Rise and Coffee", but it actually means "Breakfast").

Earlier on the day I sent message to extend the invitation to other friends. There was high probability that I will not be able to fix my Raven on time for the event! At least I somebody can be there. Well, even if I can make it, I would rather have few 'expert' fliers I know present to do the demonstration.

Reached home at about 20:15, after taken my dinner and solat Insya, I started focusing on the Raven again. Continued to fix the Rotor head, make sure the screws are firm enough, using the threadlock I have.

Looking at the situation, it with very low chance that Raven will be able to fly successfully by tomorrow morning. I have not put the blade and checked the pitch, then I will need to test it, if I have the time. And if I do manage to test it, I won't have enough time to fix any problem found in the test!

I made my mind, regardless of the Raven condition, I will still be present at Sri Pentas for the event tomorrow. At least I can just watch how it was made and get to know other fliers. Even if i got Raven in the perfect flying condition, I am not the best flier in town and other better person will be flying for the demonstration any way. Yes, just continue with what I can do. This is good opportunity, I will do my best!

At 00:00 (midnight) I completed the fix, left only main blades and pitch setup. Oh, the main blade got its own story. To cut the story short, Cikgu Vanan do not have any stok, he has given me for free a used wooden blade. I am supposed to balance the blade since it may not came from the same pair and furthermore the blade condition is not that good.

00:41, the Raven is ready for the test flight. However, I was thinking, thinking very hard! Should I test it. It was already very late. Where can I test it? Will I disturb the neibour? I need to find a place far enough from the houses. Yet, I need to find a place where have enough lighting. And furthermore I need some big space for it to fly. Those are a lot of question which I don't have the answers. It is easy to just let it go and wait for tomorrow, but should not I let it go easily and risking the big opportunity of flying the Raven under live coverage tomorrow.

Thinking... am I that insane to do the testing this late?? ..

Then, I decided, I will do the testing! Insane? Well, call me anything, I don't thing it is wrong to do that.

Put all the required stuff into my car, started to drive around Putra Height, I need to find the suitable place.

Found a place, probably it is suitable. It is at Putra Point (shops area in Putra Heights). Entered the area, there was a small mamak food store still open, beside it is snooker center. There big parking space in the front, with some lighting. Yes this should be ok.

I parked my car, brought out the Raven and equipments. After a while, few person from the Mamak store and snooker center came over to watch. Yes, this RC Chopper attracts many people.

- Did the ground check ok
- Then start the engine. Engine started ok.
- Continue to check the controls. All controls response as expected, blade pitch, foward/backward, left right, rudder and engine throttle.
- Continue to watch engine RPM and sound. So far so good.

Then I increase the throttle, slowly, for lift off, the engine spin faster and faster, with louder and louder sound. Suddenly, I heard weird sound! Looks like something has gone loose.

FID: H3.E2.G2.T8.2 2009-03-14:0115
OGT: 0 minutes, Loc: Putra Point Shop Area

Aborted the take off, shutdown the engine. Definitively something is wrong somewhere, need to get it fixed first.

I sat down for a few minutes. Thinking, what should I do, how should I continue..

Regardless, I will be there at Sri Pentas for TV9 "Nasi Lemak & Kopi O" program. If I am lucky enough I will have time in the morning for a quick fix and it will still able to fly during the event!!

Packed all the stuff and get back home. Went to sleep at about 3:15.

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Fixing the Raven for the TV9 Live Coverage

I was quite depressed on the crash. However, nothing much I can do other than fixing it! Thanks to all plurk-friends who have given me support and strength to deal with the crash.

Root Cause

After checking the damage, I found that the most probable cause of the crash is due to lose metal gear on the top of counter shaft. If have checked the screw properly and make sure it was tight enough, I could have avoid the crash!

From Remote Control Helicopter - 2009

Damage assessment

From the assessment, I found only these items impacted:
1. Main blade, broken
2. Vertical tail fin, broken
3. Bent Flybar
4. Bent Feathering shaft, its the shaft that holding the blade grips to the main shaft.
5. Right lower metal frame, badly dented.

Fixing the Raven

On the same night, Monday night, I dismantled the right lower frame without any problem.

I was hoping that the main shaft is still ok and can still be used. I took out the main shaft from the upper frame. It was much easier this time compared to the previous time where I have problem to unscrew the shaft collar. Having it outside the frame, I can carefully examine the shaft, and it is a bit bend. No choice but to replace it.

I have glued the broken vertical fin together with super glue. That should work.

I have left the the frame and shaft for 2 days, focusing on other stuff in my life.

On Wednesday (11 March), I received a message from a fellow flier in Damansara, a local TV station, TV9, is going to do live coverage on the Remote Control Helicopter Hobby. That means I need to fix the Raven fast get it to fly, or else I will miss this opportunity, 'big' event that won't come every year or even every 10 years. I quickly send message to Cikgu Vanan to make sure I have the replacment parts available. Yes he have it!!

On Thursday (12 March), after work, I left office at 7.30pm to Cikgu Vanan's shop to get the replacement part for the main shaft and feathering shaft. Also over there, I have managed to straighten the dented metal frame.


The replacement part on cost me RM42! That is quite low, looking at how the Raven crashed!!

Reached home at about 10.30pm, and start fixing the Raven. I started with the hard part first, the feathering shaft. It is hard becase the 'damper' is very tight, and all the tiny bearings and spacers which I need to be very carefull with.

Taken out he bent feathering shaft, then I realized I have one ball of the bearing missing. It is a very small tiny ball, I was looking for it for about 10 minutes, few times at the possible dropped locations.

From Remote Control Helicopter - 2009

I checked every dust and food waste on the floor, sensing them with my palm and leg, almost give up! Looks like I will not be able to continue and probably will have to skip the Saturday morning TV coverage as well. :(

While doing all these, lucky for me I have a very good friend accompanying in plurk! That have really given me more energy, not to give up easily. Yes, have the sense of .. hmm can't find the word here.

Finally, I checked back the bearing, after counting the balls and compared it with the other side, looks like all the balls are there. It have all 9 balls, they just shifted the place, making big space area giving the impression of the ball is missing. Alhmadulillah. Happy again, now I can continue.

I reaarranged the ball. Put in the feathering shaft and assembled back the blade grip. This also consume considerable time of me as well. Completed that part and went to sleep at about 3.30am.

Early morning on Friday, I managed to contine, putting back the lower frame and main shaft. Then I attached the upper frame assembly (was not damaged and no fixed other than tighten the metal gear screw) and it was ready for engine running test.

Unfortunately, my glow plug has no power anymore. I have not charged it for some times, need to charge it first. Put it on charger and I left home quite late to office! Yes, this is not a good example!!

I need to come back home early today, need to continue to make sure the Raven is fit for flying! TV9 live coverage, I must not miss this.

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5 Month Mark

Today is exactly 5 month since 9-Oct-2008, the day I brought the Raven back to my house after I just purchased it!

I have been satisfied with the Raven flying performance in the previous flights, and today is the day were I will be trying inverted hover again. The last time I tried the loop and inverted hover, it ended with very bad crash!

I this was long holiday weekend, Monday is a public holiday for MaulidurRasul celebration in Malaysia.

I have been looking for the time to fly since Saturday, only Monday I was able to find the good time. I was fully occupied with some family activities and the MaulidurRasul celebration at the nearby Surau. Also, I was having problem with broken glow heater before. I had successful put it back using super glue.

It was about 9.30am. Since other fellow fliers in Putra Heights were not flying today, I decided will do the flight session at the nearby PH9 football field area.

I setup for the flight, begin with ground check, making sure all links are firmly attached, and all controls are working for both of the batteries.

Starting up the engine, I was trying to start the engine using the other glow heater which has been charged for about 6 hours or more, but it did not work. Changed to another glow heater ('super glue'd one), engine started right away.

FID: H3.E2.G2.T8.1 2009-03-09:0945
OGT: 08 minutes, Loc: PH9, Football Field

Lifted off, did in flight check, all control ok, switch to idle-up mode, continue with the hover check. Everything is ok. I proceed with figure 8 flying and few stall turns. I brought it back to land, checked the engine temperature using the '5 second finger' method. The engine was not hot at all, seems that I can put my finger there all day without feeling any pain.

Then, lifted off again. Now I am ready with the real flying. I did few stall turns. I was quite windy, can feel the wind from my left to right. Doing tall turn on left side made the Raven a bit drifted to my side, I need to be careful, not to let it fly near to my place on the left side. I tried the negative pitch during the stall turn, it works, the Raven moved accordingly.

So now I am ready for the inverted hover.

From my left side, flew the Raven to the right, then up for the flip.
I was not a perfect flip, the Raven ended up inverted with left side a bit low. Quickly my finger automatically compensate and fix the attitude. It stabilized for 1 or 2 seconds. That should be enough, I started to push the 'elevator' up and increase the engine/negative blade pitch to flip it back up right.

Suddenly, at that moment I heard the engine screamed in high pitch.
Oh my god! I shouted in my heart. Something went wrong here!

Regardless, I continue to flip it back up right. While the Raven flipping, I can hear the engine continue to scream. The Raven started to descend while it was flipping back up. The flip rate was not good! I can see the main blade rotating much slower now, about 2 seconds later the Raven hit the ground on its skid, bounced and rested in inverted position. Still panicking, I realized that the engine still running, quickly I flipped the switch to shutdown the engine, only then it stopped.



Flipped it manually up right, I can see the broken main blade and bend fly bar.



Even the right side frame is dented.

From Remote Control Helicopter - 2009

However, looks like the damage is not as severe compared to my previous crash. No damage at all to skids, tail boom and hopefully main shaft too. Alhamdulillah, I guess, the last second maneuver before impact have reduced the possible damages.

I brought it back home. Just to make sure the engine is still ok, I tried to start the engine. Since the left frame is dented, the holes for starter shaft to the metal fan is not aligned anymore. I need to detach the upper part to access it.

I was able to start the engine, yes it is still working!

From Remote Control Helicopter - 2009

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Quick Real-Flight

I am very glad that I can spend the time to fly the helicopter this morning.
I have adjusted the swachplate, make sure it is level (using only my eye!). Also I had re-setup the blade pitch, now with +10 to -9 degree.

FID: H3.E2.G2.T7.1 2009-03-03:0910
OGT: 12 minutes, Loc: PH9, Football Field

I brought the Raven to the Football Field new my house.

From Remote Control Helicopter - 2009

After a few tries I was able to start the engine. However due to throttle servo trim adjustment I made before, it died a few times till I got the correct level.

In the process I also have my Esky Glow Heater broken! Not sure it is really due to bad quality of Esky products or it just me. Probably I can just glue it back and still can use it.

From Remote Control Helicopter - 2009

Took-off, did in flight hover check. Everything is ok, proceed to idle-up mode.

I flew figure 8, left to right, and back, hove in nose-in position, then continue with stall turns.

I remember last time when I started to learn the figure 8 flight, I felt that the field is not big enough for me. Now not any more! I can feel that I have lots of improvements.

From Remote Control Helicopter - 2009

Finished the session about 20 minutes later. Drove back home in happy state!

From Remote Control Helicopter - 2009

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New Gear Test Flight

2009-03-02 Monday

Yes, the Century Raven TR3703 was ready for the test flight. I had completed the assembly and setup right at the sunset time on the day before.

Just need to make sure the Raven is fit to fly, I conducted these test flights.

FID: H3.E2.G2.T6.3 2009-03-02:0740
OGT: 0, Loc: PH, in front of my house.

Using the existing fuel from last week (tank no 6). Tried to start the engine. The engine is quite heavy to be cranked at first. It has been more than one week from my last flight/engine start. Recommendation from experience fliers, if engine will be rested for more than one week, it need to be cleaned with 'after run' oil, I did not put the engine, not expecting to have the major maintenance.

From Remote Control Helicopter - 2009

I managed to start the engine, not that easy, but after few times of trying it started up ok.

Playing with the throttle, I noticed some unexpected sound weeking out form the helicopter. I suspect this is due to the fan touching the upper frame.

After about 1 minute, I decided to abort the take-off, better fix the problem first.

Bring it back home, take out my drill and make a bit of adjustment to the screw hole at the server tray. Looks like only one side need the adjustment.



FID: H3.E2.G2.T6.4 2009-03-02:0815
OGT: 3 minutes, Loc: PH, in front of my house.

Engine started easier this time.

Yes, no more weeking sound.

After looking left and right, I decided that it was safe for take off. (I don't recommend to fly nitro rc helicopter at housing area!!)

Lifted-off ok, all controls basically ok, however I fill the helicopter temp to go backward. Need to compasate that tendacy with forward control.

Brought it up to hover at chest level, where I checked the 'blade tracking'. Blade tracking is perfect! After few more minutes of hovering, the main tank is empty, it was continue to run from the header tank fuel.

I slowly brought it down for a safe landing.

One of the neighbor was looking at me from his house, probably he was mumbling about the inconsideration of me flying this helicopter early morning around the house, or, to think positively, probably he was very interested to join me flying remote control helicopter !

Anyway, the test flight result is : PASS

I just need to do some adjustment at the swatchplate/servo/linkage, so that it will not tempt to fly backward.

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Ground Maintenance Part 2

I have the Raven dismantled and ready for reassembly. However, I realized that I have left the helicopter tail and the main shaft at Cikgu Vanan's shop!

This was the first time for me putting up together the upper frame part myself, so I was very careful, doing and learning at the same time. Luckily I have the Century Raven Manual which I downloaded from the Century Helicopter web page, it was very helpful.

From Remote Control Helicopter - 2009

I dropped by at the shop on the Saturday night to pick up the tail and main shaft, reached home at about 10.30 pm (after some shopping with family).

From Remote Control Helicopter - 2009

The epoxy has settled for about 24 hours, that should be sufficient for it harden and hold the broken part.

At the same night, I managed to just fit in major parts into the frame, they are tail gear, main gear, counter gear and their bearings. These are the important part, any mistake here, I will need to open up the frame again!

From Remote Control Helicopter - 2009

Next morning (Sunday), I continue to put the screws, servo brackets and other parts.

Of course while doing this I also need to stop and manage other humanitarian/family/home stuff as well.

By 6.54pm I have the Raven put in together except for the main blade.

From Remote Control Helicopter - 2009

Continue to complete it. Finished pitch setting at about 7.25pm. I manage to get +11 to -10 degree in range for the main rotor blade pitch.

From Remote Control Helicopter - 2009

Ready for test flight...

From Remote Control Helicopter - 2009

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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

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