HELP!! WOBBLE PROBLEM!!!!
 

It all started when I broke the set of main blades that came with the heli. After replacing the baldes the heli vibrated alittle when throttling up. No problem, I understand that simply because you put new blades on a heli doesnt mean they are a matched pair, so I matched a pair up as perfectly as I could. When I throttled up there was a very slight vibration again but nothing that would mess up or throw off the helis flight (I've flone before with this VIBRATION with no problems). Well' after I throttle up, giving mor power, I begin to lift off, the vibration goes away. Once I get about 2 feet off the floor, the heli flys normally for a couple seconds then suddenly, the whole heli, from head to tail begins to wobble violently to a point where with a new charged 7.4 lipo battery, it wouldnt ascend anymore and I have to bring it down quickly before it crashes to the ground! I've been trying to figure this problem out all weekend! I've taken it apart when I discoverd the frame was broke, changed rotor heads, flybar blades, and checked the shaft when it was apart to see if it was broken but it wasnt!. This heli seems to be plagued with those violent, in flight wobbles!! What else could it be??!!! I have an extra lipo. I'll put that one on to see if theres any difference...HELP[X(][:o]

RE: HELP!! WOBBLE PROBLEM!!!!
 

Well, it's hard to say for sure since you don't say what kind of heli you have, but I'm going to guess it's FP, maybe a DF4.
Generally, I've found that when everything else checks out, it's a problem with the new blades. Try running them quite loose, and then quite tight, and let me know what happens BOTH ways. Also, did you balance them and set the tracking?
I've found that 99% of the time a wobble is problem with blades.

RE: HELP!! WOBBLE PROBLEM!!!!
 

Hey GTXSLOTCAR, yes, I beleive its the blades as well. oh yeah, its a DF4. I just find it hard to beleive that almost all the blades I have are this way. One thing I noticed is the replacement blades are alot thinner and flimsier than the stock blades. You mentioned balancing them and tracking them, can you tell me how I do that? Thanks in advance. :)

RE: HELP!! WOBBLE PROBLEM!!!!
 

You can look at [link=http://www.rcuniverse.com/forum/m_4904271/anchors_4904271/mpage_1/key_/anchor/tm.htm#4904271]this link [/link] or [link=http://www.rcuniverse.com/forum/m_3690435/anchors_3690435/mpage_1/key_/anchor/tm.htm#3690435]this one[/link].

RE: HELP!! WOBBLE PROBLEM!!!!
 

Or this one:

http://www.dream-models.com/eco/Blade_balancing.html

RE: HELP!! WOBBLE PROBLEM!!!!
 

I have been balancing them on the heli and it seems to be ok. I don't have any balance vibrations.
First I set the blades a little stiff, but loose enough to spin out straight.
Then I spin it up until they are out and vibes are minimum.
Next spin down SLOWLY.
Loosen the motor and move the pinion off the main.
Turn the heli sideways and the heavy blade will fall.
It usually takes one or two 2 inch strips of scotch tape running with the chord of the blade and placed towards the tip.
Set your pinion back.
Done

And I will also do the paddles without the blades on first.
Pretty quick and easy. And I have sometimes found more effect from offset of the rotor head on the rotor head bearings. Look up under the head and you may see it. Not much can be done about that, except maybe balancing it on the heli.

SB

RE: HELP!! WOBBLE PROBLEM!!!!
 

Had this same problem.

My solution was the battery tray w/combo landing skid rods were coming out of the frame during flight causing the battery to get off balance and shake baddly.

Take some elmers glue, not super glue, and make sure its nice in even and glue the skid rods into the frame and let it dry.

try that and see what happens.

RE: HELP!! WOBBLE PROBLEM!!!!
 

Have to revive this thread for my problem. I have a #4 that developed a terrible wobble after crashing and having the main blades replaced. I have tried a well matched pair of blades and I still have this wobble, rather violent, screaming something obvious. The main shaft does not appear to be bent when running it up without blades. What else could be the cause for this?

RE: HELP!! WOBBLE PROBLEM!!!!
 

Make sure the blades are balanced, meaning take them off the heli and bolt the ends together so you have one long blade. Once done, then hold the blades at the bolt (with your thumb and pointer finger). Look for the higher blade. Take some scotch tape or duct tape and put it on the end of the higher balde until its level with the other. That should take care of you problem.

RE: HELP!! WOBBLE PROBLEM!!!!
 

My blades balance out perfectly. Anyone else have any ideas? It almost seems that the wobble gets better and worse as I am hovering, and by battery, etc is secure. I'm at a loss here.

RE: HELP!! WOBBLE PROBLEM!!!!
 

I was having a problem with mine wobbling until I put spacers on the shaft between the E clip and the top of the body. Reason it was wobbling for me was because the shaft was traveling up and down when I would spool it up. Apparently the motor was mounted slightly crooked and it would grab the spur gear and shove it up and down at different RPM's. This probably isn't whats wrong with yours but I figured I would mention it.

RE: HELP!! WOBBLE PROBLEM!!!!
 

i had a bad wobble in my 68 after a hard landing. checked the blade balance,tracking, still there,with the main blades off the heli its hard to see any damage to the main shaft..I removed everything down to the swash so nothing is spinning with the main shaft but the washout base,spunup the moter and noticed a slight wobble in the main shaft(less than 1mm) that could not be seen with everything on the heli. Just a slight bend to the main shaft and everything wobbles

RE: HELP!! WOBBLE PROBLEM!!!!
 

I have found that the replacement blades are thinner and more flimsy. If you lock down the heli in a vice or heavy weight and then do your spool up slowly you will notice at eye level that the blades will flex at different RPM's. If the blades flex up from center to outter edge you will lose your lift plus pick up vibrations.