Blade 130X wobble (Full Version)

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BottomGun -> Blade 130X wobble (8/10/2012 12:42 AM)

I've had  my 130X for about three weeks and have been doing mild circuits around my yard, being this is my first CP heli as a step up from my 120SR. I've had a few crashes into soft grass and aluminum siding, but generally besides the vertical fin snapping in two, nothing has phased it. Recently I've been noticing a wobble that happens about every five seconds while hovering and forward flight. Sometimes it's mild, but sometimes it can shake much more significantly.
  I went ahead and inspected my main shaft and found it had a hairline crack. I thought this might be it. After a new mainshaft, along with a new main gear and feathering shaft unit installed, it's still doing it. All my other gears are fine. My LHS owner inspected it and even flew some 3D with it and said this is normal, but I know that it isn't, as I did not have this problem when I bought it, and I don't see it happening in other 130X videos being posted these days, even after they have crashed their's.
 Any experts out there have any clues as to what it might be?  Both main and tail blades are new, so that can be ruled out also.



john josey -> RE: Blade 130X wobble (8/11/2012 12:24 AM)

Is it possible for you to post a video of yours doing the wobble ? That way we should be able to get the problem resolved quite quickly. 

                                                   cheers
                                                         john



BottomGun -> RE: Blade 130X wobble (8/11/2012 2:43 AM)

I'll see what I can do. I just ordered one of the new optional metal tail gears if for no other reason just to have a more resilient gear. Since it's apart I'll wait until Tuesday when the new gear arrives and put it in. One thing that I did this afternoon was notice that on the tailbox, I was able to push it in a little further to seat it into the boom. I've read about this occuring with other owners, so I put a very small dab of ca glue on it to keep it there. Hopefully that might have solved it. The wobbling was not a tail wag or spool up vibration, it was the entire copter shaking while in flight every five seconds or so. It did it in both normal and idle up modes, whether it was hovering or in forward flight. You could see the landing gear shake side to side a good half inch during some of the worser ones. 



john josey -> RE: Blade 130X wobble (8/11/2012 11:19 AM)

It sounds like the 'e-flite servo jitter issue' to me



john josey -> RE: Blade 130X wobble (8/11/2012 1:47 PM)


quote:

ORIGINAL: john josey

It sounds like the 'e-flite servo jitter issue' to me



If it is the servos 'jittering' then the cure appears to be swapping the 'O' rings on the swashplate for the spare canopy grommets that come with the heli. This will tighten up the links nicely.

I can post a picture if it helps ?



BottomGun -> RE: Blade 130X wobble (8/11/2012 4:21 PM)

Actually, based on the advice of my LHS owner, the grommet swap was the first thing I did when I got the heli. Like you said, I just substituted the o-rings for the canopy grommets to eliminate the play before I even did my first flight a couple of weeks ago.



john josey -> RE: Blade 130X wobble (8/11/2012 10:44 PM)

If you can post a video when you have the heli back together, we'll see where we are from there.



BottomGun -> RE: Blade 130X wobble (8/12/2012 6:52 AM)

The problem has been solved. I went ahead and put my old gear in and flew it. Couldn't wait. Still shook around like crazy which means the tailbox treatment didn't work either, so I decided to go to another HH stocking LHS that I've done business with before. He turned on the Tx and heli and waited for it to initialize. Worked all cyclic controls okay and we noticed that the tail servo was acting a little hesitant. This time he disconnected the motor after turning heli off and then reinitialized it once more. Tried cyclic controls again. They moved a short distance and then FROZE. Wouldn't move at all with input. He said that on these analog linear servos that if you have one giving you a problem, it will affect the others as well. Kinda like a cheap set of Xmas lights. I didn't think it could do that. He suggested a new tail servo, so I went ahead and put out the 16 dollars for a new one and went home and did some remove and replacement. Put in a fresh battery after installation and powered it up to check all functions. I went ahead and lifted it into the air and now it's hovering as smooth as silk with absolutely no in flight vibration whatsoever. So this analogy can be added to the list of possible causes for in- flight vibration problems as well.
  I'm just glad I didn't have to ship it out to HH. I did have  some small mishaps in thick grass before and I would guess that the tail servo got damaged in the process. Nonetheless it's working fine now.



john josey -> RE: Blade 130X wobble (8/12/2012 9:10 PM)

RESULT !!!

I'm pleased you managed to get it resolved, i know how frustrating these things can get if it drags on without being resolved.

As you said, it may well have been one of your 'bumps' that caused the servo to be faulty, unfortunatly no way of knowing for sure.

Apart from having to add a small piece of tape to one tailrotor blade, to stop the violent vibration on spool-up, mine has been flawless (long may it continue)
[IMG]http://i709.photobucket.com/albums/ww97/boaby_2009/Image0716.jpg[/IMG]

You do realise you can adjust the gyro gain on all three axis to fine tune it to your needs as your flying progresses. I cannot rate this little helicopter highly enough, just a pity they were not available 20+ years ago....would have saved me a lot of money and heartache.

                      Take it easy
                                  john



BottomGun -> RE: Blade 130X wobble (8/13/2012 5:56 PM)

  Thanks, and I know what you mean. 30 years ago during the dawn of the new 'Cricket" heli that some people had at the flying field and was even at that time outside my budget, I remember mentioning that it would be neat if someone invented a palm size heli that you could fly in your house or small yard. Some pretty much scoffed at the idea saying that it would be an impossible task to miniaturize all the components needed to make it happen. Electric flight in general was very limilted then. Witnessing the advances made in this hobby since then are incredible. 

   On the gyro, I went ahead and decreased the yaw(rudder) gain by four points and it stopped the tail from trying to overcorrect itself,something I see referred to as "tail wag". Despite the critisizms that I've read (and some of them have merit), I think these little machines are great learning tools for people like me that want to advance into CP helicopters after flying the 120SR. I've read arguements that their price point might be high for what it is, but being that I dumped it into the ground about seven times, I know that I would have been shelling out at least the equivalent cost of the 130X in replacement parts on a 450 size helicopter by now.

   I've greatly improved since then and have been flying cicuits around my front yard and actually did my first inverted on idle up mode. Not a big deal, but a big advancement for someone trying to learn coordination skills needed for flying these neat little guys.

                                                                                                                                                                                          Take care.



BottomGun -> RE: Blade 130X wobble (9/2/2012 7:29 AM)

New update:  My tail started to jitter back and forth violently during a recent flight. I replaced C and D gears along with new metal A gear. I made sure that the tail boom was adjusted so there would be minimal slop between gears and it still did it. I was up against a wall trying to figure what it was. I put it into a hover next to me and observed the linkage rod vibrating back and forth in a rapid manner, so I took off the recent new tail servo that for a while corrected my earlier problem(with no crashes), and I replaced it with my supposedly bad servo ( I kept it just in case). I spooled it up and the tail was rock steady. I put in two more flights to make sure all was well. No problems. Go figure. Since there were no crashes with the new servo, I'll probably take it back to my LHS to see if I can get a new replacement and keep it aside just in case.



john josey -> RE: Blade 130X wobble (9/2/2012 12:54 PM)

Ah, very strange indeed ! The only thing i can think of is the servo plug to the board wasent seated properly. It's the only thing thats been touched between it working and not working ?

Of coarse the real test would be to change them back and if it works ok then it probably was the plug.

My goodness !!!! the GMP cricket, yeah it was way out of my reach at the time aswell. we had the micro mould 'LARK' here in the UK. You may be new to helicopters, but have obviously been in the hobby for many many years.



BottomGun -> RE: Blade 130X wobble (9/4/2012 6:05 AM)

I just discovered another little tidbit of info. I took off my CF tail boom because I'll be replacing the tailbox with a Rakon heli upgrade.
   To my surprise the tailboom was completely split in half almost 3/4 the length of the boom from the tailbox end. I would surmize that this would be a major source for tail wobble. I have no idea how long it's been like that. The tailbox was literally holding it closed. I never could even detect a hint of that by looking at it when it was assembled because to me that dark CF can hide a crack. Better start wearing my reading glasses when inspecting this heli I guess. I'll pick up a new boom this week.

 



Kmarks -> RE: Blade 130X wobble (10/7/2012 2:56 AM)

Ok I guess now it is my turn.

I have had my 130X for 2 weeks and had the same tail vibration issue as most. On mine it occured on the first flight! After checking all the control linkages, gears, and ball bearings, I came to this conclusion.

1. The tail shaft diameter seems a tad bit too small of a diameter then the inner diameter of the 2 flanged bearings that it slides into. These flanged bearings then seat onto the plastic fiber tail case. Upon the begining of these tramatic vibration episodes as the RPM increases the entire system violently shakes and slop is created. This all occued in 2 flights, no crashes, no dings and good observation.

After calling HH, I decided to purchase aftermarket alluminum tail everything. On the 3rd through 15th flight, again not one crash here is what I have:

1. Tail rotor Perfect. No vibration at all.
2. Now the body begins to "Wobble" at the main axis at certain flight conditions. The wobble works through but RPM decreases and flight control decreases during these wobble events.

So here is what I have.
1. 20 flights
2. No crashes.
3. New non bullet, and Bullet blades ( no dings )
4. New tail assembly with no vibration.

I checked all gears, etc. All engaged and working OK.

Any Idea's??????

Thanks Fellas.

By the way, this 130X is actually so good it is amazing!!! We just need to figure out some of the problems.

Kevin



BottomGun -> RE: Blade 130X wobble (10/7/2012 8:40 AM)

I have read that one source of wobble is the swash linkages are too sloppy with the existing grommets that are on the swash from the factory. A popular fix ( and it's been mentioned pretty commonly) is to take the spare grommets provided for the canopy and use them as a substitute for the stock ones. I have tried this and it seems to help. Or you can get #003 O-rings from a hydraulic hose and related parts vendor and use those. I got about 30 of them for fifty cents and am currently using them instead of the canopy grommets.
    Not bagging Rakon, but the tailbox unit that I got will probably go back to them because mine at least never fit square on the end of the boom. It caused even more vibes than I had before and would make my C gear round out prematurely on the torque rod. I put the stock one back on and have had no problems. All new bearings all around and it runs quite smooth.



BottomGun -> RE: Blade 130X wobble (10/17/2012 7:25 AM)

I still had a little wobble in the main rotor so I tightened up the blades a little more and it completely went away. I've been watching it close for the last eight flights and it's still good. Together with the new blade holder grommets it even trued up the blade tracking which was really off before I tightened them.
    Even with a new MH tailbox unit to replace the Rakon unit I had, I still got vibration in the tail during spoolup.  After all the various fixes that I've read about on how to get rid of the tail resonance, I settled on trying the method of applying a small square of scotch tape (or clear packing tape which is what I used) about 4mmX10mm and placed it on the lead edge about at the halfway mark on one of the tail blades. I spooled it up and it buzzed for longer than it normally would. I shut it down, took off the tape and placed it on the other blade in the same manner. I spooled it up again and I have to say it was almost like magic. Absolutely no resonance in the tail whatsoever. I can spool up gradually and wind down in the same manner and there is no vibration or shudder at all,period. It's the smoothest my heli has ever run.For me at least, this seems to be the most surefire way of eliminating the problem.
  I also have to say that with my new MH tailbox in conjunction with my existing Rakon pitch slider, I have put the rudder gain back to the factory setting. It runs without even the least hint of tailwag, although new bearings in the original tailbox together with a better pitch slider would solve the problem probably just as well.



john josey -> RE: Blade 130X wobble (10/17/2012 12:50 PM)

I feel bad for the guys that are spending small fortunes on aftermarket upgrades for the tail when a simple piece of sticky tape provides a complete cure.

I think the cause is the long flat on the output shaft that locks the bevel gear to the shaft, balancing the tail rotor assembly as a single unit doesnt show up any static un-balance, but dynamic balance is the culprit i believe, but have no way of proving it.




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