capt. crash

Hi all, I'm pretty new at RC heli's, but anyways here's my history and what happened:

i've had my eflite blade 400 for roughly a week, and today i was just started to get pretty good at tail-in hovers. I've had a few minor crashes so before with replacing feathering shaft, new blades, 1 broken grip, and eilron servo w/ a stripped gear. edit: oh and the landing gear died on a rough landing, fixed up with epoxy and became better than new, can take quite a beating now.

basically, i was about 1 minute into my battery, and after an ok hover (like 1 ft off the ground) that lasted about 45 seconds (i fly in a 10 x 6 area, so i have to abort frequently). I then started up the motor again, and when i was just under hovering throttle level, my heli basically exploded. I was still on the ground while it happened! not as in fire, but it seemed pretty bad and scared the crap out of me.

So far I have found damages of:
one blade broken in half (other is perfectly fine),
feathering shaft at 45 angle,
flybar shafts,
both blade grips,
all 3 front servos stripped badly,
2 servos that when power is on constantly run w/o input,
one linkage bent and detached,
seesaw thing with both balls removed and it's linkages detached
ailron servo arm/connector thingy broken in half
and probably a few other things damaged.

so far i know rudder servo and basically all the rear things are looking perfect. not a scratch on the boom, servo and gyro working perfectly, as is the belt. the esc, reciever etc. is functioning properly as well. does anyone know what the hell could have happened?

note: the damage actually isn't quite as bad as i first expected, at first it looked like the top rotor assembly was totaled, but it's actually mostly in good shape.

Twmaster

Sounds like one of the links/arms came off got tangled in the head and the rest just blew up.

Wow.

Since the stock servos are basically not suited for the B400 you may want to go with new HS65HBs while you have her apart.

I've not heard of this issue on the B400 but I have heard of this on other CP helis.

Twmaster

One good thing about the B400....

While awful looking that won't cost an arm/leg to fix. You'll have as much in servos as the rest of the bits I'd wager.

capt. crash

thanks a lot,

upon further inspection, i'm pretty sure it's not going to be that expensive to fix. i already have the feathering shaft, blades, and grips, just need the seesaw thingy, connector, 1 linkage, and probably new flybars as they are in a lovely C shape. It was just like what the HELL!? when i had just flown it better than i had every flown it before 15 seconds before it blew up on me. oh and an interesting thing- my battery somehow got ejected and flew across the room. luckily it's still fine. how often/why do the linkages come loose and get jammed, and how do i best prevent it?

I plan on upgrading (well if you can call it that in this case) to the 65MGs, as i hear they're the most durable. for those 3 servos will i need a BEC as well, or will the stock ESC be fine?

and thanks a lot for your reply!

capt. crash

wow! total cost of parts for me to buy (since i have a few spares already ) is only around $20 without the servos! I must say this is a lot better than i expected, especially since I was already planning on replacing the servos asap so now i finally have a good excuse! . I must say I'm rather happy with the B400 other than this little unexpected attempt at suicide. I have an axe cpv3 that will now get a bit more love i guess until the repairs are done. I still haven't found all the small parts that flew everywhere, i'm still missing a screw and all the little broken plastic bits that flew off.

Can anyone explain to me why/how the "link/arms" could've gotten loose and how to check for and prevent it, as well as if i NEED a BEC with the new servos i'm gonna get?

sorry for the somewhat double post, but I'm rather happy about the low cost of the repairs considering how bad it looked at first.

thanks!

Twmaster

I'd go with the 65HB servo rather than the MG. Save the money. You'll never kill Karbonites on that heli so metal is not needed. The money saved on the three servos will buy your replacement parts.

The short answer is that balls/links wear out. You must be vigilant and check for sloppy links. It happens.

Did you say one of the links was bent like a 'C'?? I'd bet that was the one that came off and got tangled.

A BEC will never hurt to install. If you are running the stock ESC I'd just do it.

Alpha_&_Omega

i'd go with the mg's and a castle 10 amp bec, better safe than sorry. about the explosion. back when i ad a b400, the same thing happened to me. the problem was that i did not remove and locktite the bolts on the feathering shaft. one rattled loose and my head exploaded. use locktite sparingly so you don't freeze up you bearings and you'll be fine.