Vibration or shakes? CHECK THIS!

[Tbone675]

i had the shakes BAD...did the grommet mod and cleaned the servos and its better then new.

Thanks guys

[1157]

Originally Posted by 1157

Well, I did it. Pulled it all apart and cleaned her up, but I still have the wobbles. I'm getting frustrated with this thing.

I may have spoken too soon. I meticulously repeated the servo cleaning proceedure. I also tightened the main motor, as someone had previously suggested. I tightened my blade grips just a bit, and I did a rebind (not sure why).

It's drizzling right now in SoCal, so I merely flew under my solid patio cover. I tried very hard to reproduce the wobble, but she just wanted to fly flawlessly. It looks as if I'll be keeping her after all.

What is this grommet mod? I couldn't seem to find it.

Thanks,

Stu

[Tbone675]

stick one of the spare canopy grommets over each of the balls on the swash to remove the free play.

[TheBum]

Originally Posted by Tbone675

stick one of the spare canopy grommets over each of the balls on the swash to remove the free play.

A full grommet may not fit on the elevator servo ball, but you can cut one in half.

[1157]

Originally Posted by TheBum

A full grommet may not fit on the elevator servo ball, but you can cut one in half.

I'm real confused now. I'm an idiot, I think I need a photo.

[Starcruiser]

cleaned mine up and did the grommet mod and no more wobble/shakes, was able to flip and hover inverted without it freaking out. Did end up with a uncontrolled piro towards the end of a pack while inverted (was flipping it), she went in but survived, can't say that would happen with a 450

[TheBum]

Originally Posted by 1157

I'm real confused now. I'm an idiot, I think I need a photo.

I meant cutting it in half the same way you'd cut a bagel.

[Starcruiser]

That is how I did my elev ball link, half a grommet.

[newtothesport]

Cleaning the servos really does reduce the shakes. I find that I needed a cleaning after about 50 flights. One more tip: If your heli shakes "up and down" (nose dips down and then up at about 3-5 times per second), clean the elevator servo. If it shakes "left to right" then clean the front two servos.

[1157]

Originally Posted by Starcruiser

That is how I did my elev ball link, half a grommet.

So let me get this straight, I'm putting a grommet over the ball link, which is on the ball. Is this at an angle? How can this not be binding? I need help.

By the way, I had some more exteded flghts when the drizzle stopped yesterday. My wobble is still there, but it corrects itself much quicker now. The wobble also doesn't seem as radical as it was before my second servo cleaning.

[ChrisH]

Take the servo-to-swash link off the two front servos. Slide a full grommet onto the ball, so that it sits behind the ball (on the neck of the ball). Then you can put the links back on. The grommet holds pressure against the link to take up the slop.

On the back (elevator), again remove the link. Cut a grommet in half (instead of II it looks like I) and slide that onto the neck of the ball. Then put the elevator link back on.

[1157]

Originally Posted by ChrisH

Take the servo-to-swash link off the two front servos. Slide a full grommet onto the ball, so that it sits behind the ball (on the neck of the ball). Then you can put the links back on. The grommet holds pressure against the link to take up the slop.

On the back (elevator), again remove the link. Cut a grommet in half (instead of II it looks like I) and slide that onto the neck of the ball. Then put the elevator link back on.

Okay, that makes sense to me now. That is not what I was imagining. Thanks Chris.

[lazor 22]

This has started happening to me. Cleaned the servo and still no luck... kinda disappointing as I just got this thing flying perfect and then this happens. No way I'm gonna spend $25 on this thing now that I got all I need for my X2.

[ChrisH]

Have you done grommet mod and all that shiz? Check over your blades to make sure they don't have any cracks or big scrapes...

Also tail blades: if they have any white stress marks on them ... they will NOT hold as well and can cause vibes as the blade is going in and out of track.

[lazor 22]

Yep I have the gromments mod. It helped all the shakes that the heli had out of the box. My blades are really messed up yes, but I realy thing it's the servo as I've been flying these messed up blades for a while.

[mejmea]

Also, check for:

Bent Feathering shaft
Worn/loose dampeners (You should feel reasonable friction as you slide the feathering shaft through)
Loose servo board or main board fastening screws
Loose motor screws
Excessive slop in swashplate
Head loose on the main shaft (the Jesus bolt (screw) hole in the main shaft can get wallowed out)
Main gear seated properly
Bad main shaft bearings
Bad grip bearings
Worn ball joints/linkages


Also, if you are using the FF blades with the "bullets" on them make sure that you haven't lost one of the little weights that are glued into the bottom of the bullets.

[kjdubuque]

Broke the anti-rotation guide on my frame so while I had everything disassembled I decided to clean the servos. Use a paper towel and some electrical contact cleaner and I was shocked how black the towel was after cleaning. Got everything reassembled and few it this morning and it flew great.

[1157]

Originally Posted by 1157

So let me get this straight, I'm putting a grommet over the ball link, which is on the ball. Is this at an angle? How can this not be binding? I need help.

By the way, I had some more exteded flghts when the drizzle stopped yesterday. My wobble is still there, but it corrects itself much quicker now. The wobble also doesn't seem as radical as it was before my second servo cleaning.

Update: grommets installed along with the new B grips and head. This thing is awesome now. No wobble and the blades track perfectly during entire flight.

[clintfisher]

So I think I like the MSR canopy grommets better: (http://www.horizonhobby.com/Products...rodID=EFLH2226) than the MCPx canopy grommets: (http://www.horizonhobby.com/Products...rodID=EFLH3021)

No need to cut the rear one in half. They pop on perfectly. Bamboo tweezers helped my install.

Also, haven't seem much talk lately of blade balance as it relates to vibrations...
To the new folks, don't forget to start by balancing your blades. Well, check loose main-gear first, but blade-balance would be a close-second.

A quick & dirty balance test: Put the heli on smooth ground, spin the motor up, and then let it spin down. If it wobbles just before it stops, your blades are out of balance. A toothpick makes a great blade balancer.

Vibrations and shakes are like snow conditions. There are many, and the causes are many and compound one another. I have a beautiful MCPx (the "green" one) that is so well balanced that it doesn't need the grommets at all. On my red, "ensign red-shirt" MPCx however, the MSR grommets let me get away with small "blade-nick" balance problems with very little shake.

New blades aren't always perfectly balanced either. Toothpick is your friend. :-)

Happy flying!

[buzzme]

Do you guys think that I should I try to straighten out these middle fingers or will I make them worse if I try messing with them? My concern is that the middle brushes could touch the wrong strip....???? The fingers on the other servos look nice and straight.