600 Still Got a really bad Vibration 600 DFC Trex

[Westy]

Hey Guys ... I am not happy with the heli it has got a really bad vibe in it ..... never used to do it this bad.

all bearings done except one way bearing..... including motor.

I was thinking of getting:

1. a new tail assembly
2. 12 tooth Pinion (currently running 14T)
3. a new one way bearing and spigot.


blades seem to be clicking at high speed and on big pitch changes .... could this be to high a head speed?

the vibe is in start up and has some bad spots up to take off speed. Done the tracking, CG and balance of blades

any other Ideas .... before I spend some more money?

here is it flying today .... let me know your thoughts....

 

[Lee]

I couldn't hear any clicking on the video or see any vibes. Do you have play in the tail grips? I would go over the tail and maybe change out the screws in the hub, if the vibes are strong. Any long term vibrations can quickly lead to hub screw failures. I've had it happen to me 5 times on my 450 and 500. So now a regularly change the hub screws.

 

[Tony]

Some good flying there. Okay, about the vibrations. I didn't "hear" anything like I did in the last video. The main gear change sounds like it did the trick. The big vibration on Batt-I was your main blades not being straight. Once you got the head speed up, it slung the blades out and took care of that issue. Looks like your blade grip setting is perfect.

The other "higher pitch" vibration looks like the harmonic vibration that every heli has. This is completely normal. Even the real Blackhawks and Chinooks at my base have this vibration and they are balanced perfectly.

On your tick-tock and your flips, your motor speed dropped about 50% and the motor was struggling really bad. By putting the 12T on there, that will help this out a LOT. If you still notice it, drop down to an 11T and it will bog even less. So when you get those, try that again, get it on video and compare it to this flight.

The heli sounds and looks much better than that hover in your back yard IMO.

 

[breeze400]

That little bit of bouncing in the tail is pretty much in most helis I sent it? I did not hear anything either. Looks like she flys excellent!

 

[Lee]

11T is way too low for the 600. The head speed will be +-1700RPM He will get head bobbing. Mine didn't like a headspeed of less the 1900, which is why i suggested the 13T before, which gives you and average of 2000rpm through the full battery range. 12T will give and average of 1870. Get a 12 and 13 and see what suits the heli best

 

[Tony]

I was just going off of the bogging that it was doing. That thing was bogging really bad. Either he is WAY too big on the pinion (which the heat the motor is putting out says he is), or his batteries need to go up about 20c in it's rating and is not providing enough power when the motor needs it. I agree that 12-13 is the right choice, but if he can't get that load rating down, I don't see any other choice other than going with a Scorpion motor or something.

 

[Lee]

I was talking to him the other day about tic tocs, and we discovered that he was heavy handed with the collective. When i flip the heli, i give very little collective until its over on its back then just add enough to hover it. I think Westy, you are punching it too hard on the collective. Once you are at the stage you are now, getting into tic tocs, which are one of the harder moves on the power train, the next step is to up the voltage. I could never sustain tictocs with my 6S without servere bogging. Now on 8S its no probs.

 

[stokke]

Tic tocs rape the power train. I stripped 7-8 teeth off my main gear doing those

 

[Westy]

hey guys ..... thanks (on many counts)

I have no end play or radial play in the tail, you seed me checking that at the beginning of the first battery (subconsciously of course) but I was thinking maybe the problem is 2 fold. 1... the blades might be flapping under load which gets it back to too high a head speed.

I think maybe a tail upgrade to metal and the slider bellcrank might be flexing too much and causing my problem. I just know there is something .... the other thing I noticed is the one way bearing spigot is blue (blue hot) on the top .... (not sure what that is).

So .... in summary:

I think I will try 13 and 12 tooth gear, alloy tail slider bellcrank to take out any flex in that part of the train, and a new one way and spigot. I will change each one separately and re test fly in each case to see whether any effect has been noted.

oh ... and thanks for the kind remarks on my flying .... it is becoming second nature.

*** Do you think the tail main shaft (that the blade grips connect to... could be bent a little?)

 

[Lee]

You mean the tail hub?
Take off the unit from the tail shaft and hold the pitch links together. Turn the hub, and if the pitch links move apart or together, then its bent.

 

[Westy]

hmmm ... I am 99% sure I changed that when I had my gravity touch (RX Battery connection fail). ages ago

 

[Tony]

If you are talking about the hub as Lee mentioned, taking it off the tail shaft and holding the two link balls in your fingers and twisting the center section will tell you if you have a bent block. Same way (in a matter of speaking) that you would check your feathering shaft. If your tail shaft is bent, you would be able to see that by removing the blade grips and hub and take the main blades off. Then spool up the heli about half way and put the handle of a spoon or something on the tail shaft while it's spinning. If you hear the sound change, it's bent. If the sound is smooth and you don't feel any bumps, it's straight. I personally do a runout test on it with a dial caliper made to check the back lash on rear end gears. Just did it on my main shaft on the 600, and my runout was .003". Close enough for me lmao.

 

[Westy]

yeah 3 thou is good clearance

 

[Westy]

Orderes a 12T and 13T minion and a metal bellcrank for the tail slider... lets see what happens ... need to wait another 12 days before that stuff arrives ...also ordered the parts i needed to complete my 600 head so I can either bag and tag it or sell it.... or you never know ... I might end up with another one that needs a perfect head

 

[Lee]

You have Minions now. I didn't know you were a King LOL

 

[coolgabsi]

ok... may be i missed this somewhere.. But are you governing your head speed at all ? for a bird that size it really does need a governed headspeed ... or your throttle curves set in a way that will keep your headspeed in control even if you are at zero load. Not just for the rotors, but for your motor too.

as far as your flying! it was beautiful! and i wasnt able to hear any vibrations either.

 

[Westy]

You have Minions now. I didn't know you were a King LOL

Absolutely ..... Bow down and behold ! haha

- - - Updated - - -

ok... may be i missed this somewhere.. But are you governing your head speed at all ? for a bird that size it really does need a governed headspeed ... or your throttle curves set in a way that will keep your headspeed in control even if you are at zero load. Not just for the rotors, but for your motor too.

as far as your flying! it was beautiful! and i wasnt able to hear any vibrations either.

I thought the ESC did the governing? how do you govern en electric.... other than controlling the head speed with ratios?

 

[Westy]

Ok Guys and Gals.... Just rendering a GO PRo set of vids that was shot at the same time as the one above! .... will have to shrink it down a bit ... .and then upload it to YTube..... stay tuned!

here it is Folks

Perhaps it is just the Canopy vibrating?? (He Hopes)