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View Full Version : Crash = Knowledge!


RoyRC
05-05-2008, 09:23 PM
As a new member to the hobby, I have to admit the part I was worried most about was crashing. My observation reading forum threads was everyone eventually crashed! My concern was about being able to repair these things. If you don't get it perfect the first time, it's back to the drawing board...eventually you get it figured out.

So as luck would have it I crashed the CX2 1st as I flipped it over at 30' up. Got a bit over confident after flying the B400. No flying inverted w/Coaxials! :o Replaced flybar, blades, body and main shaft. Not so bad, I just remember looking at my Blade 400 thinking fixing it would be far more complicated.

Well one week later I decided to take the Blade 400 out even though it was a bit windy and I'm still hovering tail in at this point. Took the blade up, wind took it and while trying to keep it upright it went flying by me and my son pretty quickly and I stopped it, then tried to bring it down, it tipped away from me while orientation was changing..:(
I was playing the flight tapes in my mind for some hours after....

Word of advice - Shut that throttle right away. I did and I still had one blade split down the middle went flying in pieces, the other had minor damage. Flybar bent, and then there is always the damage you learn about while you are taking things apart.

Thankfully for this and the blade 400 repair site I managed to replace the blades, spindle (yes it bent of course) and flybar (most difficult go figure). Got it all together, took it out but still major had major vibrations on spool up. That was a real bummer, I slowed it down very slow and I could easily see the main shaft bent as well. Was not obviouse without it spinning.

While parts were cheap overall, it took a number of hours, but was well worth it. Bottom line is I learned quite a bit about the heli, how it's put together etc. I also have additional items I know I will check as part of my pre-flight.

Just a thanks to all of those contributing to this forum, I found everything I needed and it made a difference! Keep up the good work with posting all the good tips and how-to's.

Observations while working on my B400:

1. There were 3 shims on each side of the spindle (feathering shaft). I know others have noted the existance of 2.

2. The flybar adapters (on the end by the paddles) had loctite. I had to cut one end off, file it down so I could slide the old bar out. A great tip I found here was sliding the new flybar right in behind the old one. A few less washers to worry about. That worked great!
Q: Have folks here used loctite on these adapters after replacing them as well? I just figured I'd check these regularly.

3. The flybar paddle control arm has 4 (2 on top, 2 on bottom) small lockdown screws.The two on the bottom were gone:wow2: I've only had 4 sessions on the B400, so something new to check w/every pre-flight.

4. Plan on buying at least a pair of ball link pliers! Makes things much easier.

Later
Roy

Wolfpackin
05-05-2008, 10:52 PM
Yup, everyone eventually gets their crash course in heli repair and setup.

I was like you and was very insecure about whether I'd be able to get the heli back together and setup as good as it was before the crash.
What I learned, to my surprise, was that my heli actually got better every time I repaired it.
I learned more each time and eventually got to the point that I really understand how these things work and what needs to be done.

I still hate crashing but now I'm confident that I'll be able to get it back in the air and it may even be better than before.

Keep up the good work.

notreallyme
05-06-2008, 02:52 AM
just an fyi on unseen broken parts from a crash, SERVO GEARS everytime i have had a blade strike the gears have stripped the same gear everytime. it's not something you really think about until you try to fly and have no control, lucky for me i heard the servo motor spinning before i tried to fly. the gears are cheap but hard to find. just make sure no teeth have stripped before trying to fly again.

SeaComms
05-06-2008, 04:51 AM
3. The flybar paddle control arm has 4 (2 on top, 2 on bottom) small lockdown screws.The two on the bottom were gone:wow2: I've only had 4 sessions on the B400, so something new to check w/every pre-flight.

Hi Roy, I think they are deleting the bottom screws on the newer models for some reason, mine were not there from new either.

RoyRC
05-08-2008, 08:35 PM
Thanks Guys for the heads up,
I did have it out the other evening, I did my pre-flight checks , servo's seem to be working fine etc. I flew it and I'm glad to say - success! Very smooth no vibration at all and managed to get a few nice hovers in. So it appears that servo gears survived. Just curious how would you check them short of opening them up?
Regarding the bottom screws in question, I'll have to take a look at one at the local hobby shop next time I stop in to try to confirm that.

Roy

notreallyme
05-08-2008, 11:15 PM
just move all servos in all directions to limits if there is any kind of jerking or the servo motor keeps running without servo movement u have a problem. it's not to hard to figure out as long as you move all servos before flight it will be obvious.