First accident on my 450 tip over.

[mike_drz]

I've been on borrowed time with hundreds of flights on my 450 pro DFC. Today is the day my luck ran out. On my 3rd flight on spool up I noticed the disc tilt hard to one side, I instinctively countered it; thinking it was wind. That was my last chance to hit TH instead I gave more collective. By the time I finally did hit TH the blades were shreded and one of the break away servo arms snapped.

I'm left scratching my head trying to find out what caused this.

Is it possible the servo arm broke before the crash or did it break as a result of the crash. I'm running a 3GX and the orange servo arms from hobbyking.

[alyon187]

From what ive read... very classic 3gx problem

[mike_drz]

I think it's either that, or maybe the battery leads got jammed in the swash. There are tiny marks on the wires, but that could just be from canopy. I hate not knowing what caused it so I can avoid it from happening again.

[Russell Harding]

Tail failure can cause rollover if the skids are held firmly inlace by grass or similar.

Also consider servo failure.

Pot or gimbal failure.

Radio programming or FBL programming issue (reset to defaults, wrong model, wrong setting, etc).

Servo failure - stripping, etc.

Electrical brownout or failsafe.

[mike_drz]

It was on a geotextile runway that was nice and flat. The model was correct because I had 2 successful flights before that, and the model match on tx doesn't let it bind on the wrong model.

I've still gotta check out the servos, failsafe is set to no throttle. It might've been a radio issue but I was only a few feet away. I'll have to launch an investigation and recreation of the accident scene. lol

Those are all helpful tips, thanks CodeMedic . I sure hope it's not the DX9 that just came back from repair. I'll have to check the monitor on it.

[alyon187]

What firmware are you running?

[mike_drz]

Originally Posted by alyon187

What firmware are you running?

I've never updated the firmware. I think it came with 3.1 and I left it with that.

I also noticed the motor pinion slid down and chewed up a bit of the main gear. I didn't have a flat spot on the shaft. I think that happened after the impact instead of causing it though.

[alyon187]

Well the pin slipping and chewing up some of the gear could of caused some vibes and or other issues in which could of led to the tip over. If it flew fine for other flights before this then something was obviously different on this one which led to it. Wind, being on a hard surface any number of things so I would think to just go about w the repairs, do a spool up without any blades and check for vibes and if all goes well give it a fly! Everything ive read about the 3gx is that 3.1 and 5.0 seem to be the better versions of the firmware so give it another go.

[conbones]

I had a 3gx and that is kind of thing i ran into with it. Would be ok for a few flights and then would either go crazy and put itself on its side or would let me get in the air and just not respond to inputs. I suspected the sats so i connected it to a new ar8000 rx. That didnt make any difference. i Sugest an ikon, beastx or vbar. They are better to set up and are much much more reliable.

[alyon187]

If you read the 3gx forum these are all classic issues w the unit. I just finished setting up my 450 pro dfc w a vbar (replaced the 3gx) and the difference in feel, performance and stability are night and day in my book. This is my second heli to set up, my first was a bx on my 250 dfc, and being new it has taken me awhile to get it tuned right w the way I wanted it to fly. Alot of it was chasing vibes and since I didnt build this one alot of it was figuring out how things were suppose to be vs not. So after much effort its flying awesome minus a small wag from time to time which im still messing w. Do yourself a favor and do what I did... ditch the b*!#&

[mike_drz]

Haha , alyon my relationship with the 3GX is an abusive one. I'm married to it for now because I'm outa work. Once I get a gig, or if I find a cheap used vbar I'll ditch the biznach asap.

A guy at the field just switched to vbar on a 450 and loves it.

[Livan75]

Its generally a vibration issue if the heli does unmotivated hard roll. Its not a 3gx issue, it will happen on other fbl's that they will get spooked by vibrations and "freak out"...

So, "right roll of death" are generally a symptom of vibrations, padding the Gyro with extra layers of tape is not a fix...

[Russell Harding]

Yes and no... 3gx and BeastX will roll. Some won't..... My IKON has NEVER done anything like this. I've flown with things bent on purpose and it is always spot on.

[mike_drz]

It was always silky smooth with no vibes that I knew of. Maybe something came loose during spool up, I guess that would cause the 3GX to freak out.

After replacing the main gear it's not so smooth. It's as if the new gear is out of round or the main shaft might be bent.

[alyon187]

Blade strike enough to break the blades... replace both shafts regardless other wise you might end up chasing vibes or see the same result that caused it the first time. Better safe than sorry.

As a precaution I would also take a look at your gears and you tt just to be sure nothing else was warped or chipped in the strike. Im a heli mech so something breaks or acts funny I check all areas that come in contact w the affected area.