AirforceRcks

Ok this problem just arose halfway through me 2nd to last flight.

when i spool up, the head vibrated then when i lift off it goes away but when i hover and it comes back as i throttle down.

any ideas? thanks

i almost crashed trying to do a circle around me without the tail at me the whole time!(i almost crapped my pants!)

Prontow

First thing I would try is putting another set of blades on it. I have found that the holes can wear unevenly between the two blades.
Oh yea, I have gotten where I wear Depends underwear when I fly!!

SchoooBaka

ROFL
Yeah, sounds like blades to me as well.
I've heard that you can drip some ca into the holes to strengthen them a little, though I havent tried it myself. When I do, I'll use thin ca, like the stuff used to glue tires on rc cars. I would think anything thicker might clog the holes.

AirforceRcks

they are brand new blades that i tested out about a week ago and this is their second flight

PilotLight

My Feedback: (1)

Mine vibrates the same way. Don't worry about it. If you find the reason, post it here for us.

Heliko

I think I might know what's causing the vibration or at least contributing to it. Make sure your dragbolts are holding close to the same tension on the blades. If one is tighter than the other the blades may lead/lag at different rates. The centrifugal force at high headspeeds with keep them straight and in-phase, but at lower speeds the center of mass and the center of rotation go out-of-phase causing the vibration. Something like this happens in real helis too. It's called [link=http://en.wikipedia.org/wiki/Ground_resonance]Ground Resonance[/link].

Rotor13B

They need to be balanced. I have a brand new set never flown and they needed balancing just like the originals that I got.

Prontow

My CP had a similar vibraton that I could not locate. This is what I do to locate vibrations, I clamp the tail boom in a small vice I have on my desk(as close to the main frame as possable). I can then safely spool up the head and watch and listen to it. Watch the head button closely it will tell if anything is bent or gotten shifted on the main shaft.
I had a main shaft that was bent very slightly, not even enough to keep it from flying but after I watched it running setting blade tracking I noticed it. After I replaced it the little bird ran smooth as butter.

PilotLight

My Feedback: (1)

Just replaced a main shaft, and main blades. Still can't find the source of vibration. I began by straightening the old shaft, and when I removed it, I found it was very straight. Decided to get a new main shaft and it was very straight. Only thing I haven't done is balance the new blades.

Anyone have an easy idea for balancing the blades to eachother? Tried placing a Hex wrench though both holes, but no way to balance without the blades swinging on the wrench.

Pictures of homemade balancers would be great.

rollingball

I use the HM blade balancer, Even though there are no adapters to fit the 2 mm blades. I take the bolts from the grips, place them in the outer most holds and use the 3 mm holder to secure the blades for balancing.

Heliko

Ok got some new info on my vibration problem. It's gone!!! No more bad vibration when spinning up or down, YIPEEE!!!

I believe most of it was a bent feathering spindle. If your blades are hard to track, or will not track at least closely, or if you get them to track, but looking closely at the pitch links they're not the same length (I actually use the gap between the links as a reference) then you may have a bent spindle. I guess my Axe's spindle was bent for a while, but it was so slight I couldn't pinpoint it till after another minor blade strike out in the yard the other day. This made the vibration much worse. In fact I found it accidentially when I spun up the main rotor head with out the blades. While I had it apart I also inspected the rest of the rotor head and sanded some flash off the the center hub with 1000 grit for smoother movement. It's seems to have worked out. Anyway I hope this can be of help to you guys that are having this problem.

SchoooBaka

What are you using to balance them?
I've got the hellimax balancer, but the smallest adaptor is 2.5mm. Are'nt the main blades on the axe cp 2.0mm?

osterizer

Yes, but you can use couple of finishing nails or grip bolts to hold them in the tray and then clamp them with the 2.5 bridge. they may be off by a fraction of a mm, but no big deal. Be careful to keep the support triangles in the exact same position when you zero it and when you're balancing the blades-- if you let the supports move, it throws off the zero point and you won't get them balanced correctly. I drew datum lines on the surface of my bench to line them up with, but eventually I'm going to get motivated and make a shaft for my TopFlite magnetic balancer so I can use it instead.

ElectricHead

To balance blades. Search the web for a guy named Bob "Finless" White. He has made quite a few videos about heli things and one of them is a simple way to balance blades with a bolt,sharpie,flat surface,and straight rod. He hangs out on another forum with a bunch of other helicoptor freaks like us.

thestratcat

My Feedback: (12)

just me.. I found that the button on top (yeah, technical terms) tends to move off center on mine, if I put the heli in the palm of one hand and press down on the button with the other, it usually lines things up and my vibration goes away...

Heliko

I use my balancer a little differently. I tried to explain it [link=http://www.rcuniverse.com/forum/m_5364052/anchors_5364052/mpage_1/key_/anchor/tm.htm#5364052]here[/link]. I'm going to update it with pics one of these days.

Foxito

Hi!

To all those that talk about Axe CP vibration, I can tell you that three weeks ago I bought a brand new out of the box Heli-Max Axe CP at a local hobby shop, and the thing vibrated so bad when spun that holding it with a hand on the air above my head it was like holding a tractor!

Later on that weekend I found that the blades were way...I mean it...way out of balance! - I contacted the store and they gave me a new set of blades, as well as the factory sent me another new set of blades....I end up good...two brand new sets of blades...hehe

But before that, that same weekend I took the blades out and tried to balance them, and because they were *so much* out of balance, I started to cut off little by little pieces of wood from the blade that weighted more, until I got them perfectly balanced... mounted them on the heli, spun it....and the thing was as smooth and nice as should be, and sounded like a jet.....shhhhhhhh...real nice, NO MORE VIBRATION! Gone for good.

The point is, if you are having your Axe CP vibrate as a tractor, check your blades balance, at least that was my problem.

If the blades are well balanced, then check tracking, or even worse it could be a bent main rotor shaft.

Regards

para_seb

i guys,

I just got my first heli, a used axe cp, and I have a small problem with it that i thought you might be able to help me with.

First when I apply any movement on swashplate, being from the cyclic or the throttle, The whole helicopter starts to shake and becomes uncontrollable. I first thought it was the blade balance that was off. So I check the balance and it was dead on. I then checked the tracking and made the necessary adjustments as explained in the Manual. it looks better now.

What else could causing the vibrations and how can i correct it.

Thanks.

Seb

Heliko

The flybar maybe? Feathering spindle? Mainshaft? I'd pull the blades and run it up CAREFULLY and check for vibration. I recently found that some of my vibration during spin-up which seems to have reappeared seems to be from play between the mainshaft and mainshaft bearings. I'm not sure what the deal is, but I'm going to replace the bearings and see if it helps. After all if you think about it most of the helis weight is being held up by a 6 x 10 x 3mm bearing.

Foxito

Hi para_seb,

Your case could be a bent main rotor shaft. In my case it was the blades out of balance right off the box. During those days (3-4 weeks ago) I conctacted the factory and they sent me a brand new set of stock blades that were perfectly balanced. But meanwhile during that weekend I checked balance on the blades that came from the factory, and they were so unbalanced, that I don't think putting a piece of tape on them would do anything. Instead I chop off very small pieces of the tip on the heavier blade very little by little (took me an hour or so) and checking balance every time until they were perfectly balanced, then tried them and the helicopter was as smooth as a baby and sounded like "sssssshhhh" like a jet as I call it..hehe.

I know I'm not suposed to cut the blades, but what the heck I wanted to know what the Hell was going on and why the helicopter was shaking *SO*MUCH* that was unsually bad, and besides the factory was sending me a new set of blades anyway.

Since then Heli-Max, Hobbico or whoever they are, have been very nice and generous to me, I got a new set of blades, I got a RX board, a got a swashplate, all FREE of charges because they have been bad one after another. - I got a "bone" from the factory out of the box....but by now I am very satisfied and happy with Heli-Max, they are heck of a great support company indeed.

Once again, if your blades are balanced, the other thing that could make your helicopter shake very bad is a bent main rotor shaft. Also check the flybar, if the shaft is not straight of course that could make the helicopter shake.

Regards

PilotLight

My Feedback: (1)

Just spent the last hour trying to find the vibration on mine. Removed the blades and ran it up with just the flybar paddles on. Had a little vibration, so I loosened the wheel collars and slid the bar over and then rechecked. No vibration. Balanced the blades, then installed them. Still a little vibration in idle up mode. Very little in normal mode. Added some tape to one blade, tried it, then removed and added to the other blade. Nothing will get rid of that small amount of vibration. I have a brand new main shaft in it, and it hasn't been crashed since the install. I'll just let it go for now. ??? Don't know where it's at and what's causing it!

Heliko

Pilot Light does the vibration get worse as speed increases?

xxxntwv

Could possibly be a tracking issue.That was the problem with mine after balancing the blades.It's almost impossible to get the tracking perfect.

Rotor13B

Check you flybar and make sure the paddles are equal length away from the head. What I did was take the paddles off and centered the flybar. Then I screw on till it was tight and facing the right way and measured the distance between the paddle and the collar. I then put the other paddle on and set it at the same distance as the first paddle. If you still have minor vibration you might want to weigh each paddle to make sure there not out of balance themselves. A small amount of scotch tape on the lighter paddle should help bring them into balance. Using a digital scale here works wonders.

Rotor13B

I'm using a Kyosho blade balancer to set the balance AND the CG of the blades. I loosened the anchor bolts and replaced the "drag bolts" with a couple of toothpicks and snugged down the drag bolts again. After balancing, I then put the original bolts back in and checked the cg of both blades. If there within a mm or so the you should be ok, But if there spread out farther you want to match the cg of the " heavy blade" on the lighter blade. Once you find the cg, mark it with a felt tip pen and line up the blades and mark the second blade inline with the first. Then it's a matter of adding tracking tape or scotch tape to the light blade where you marked it until it lines up at zero on the balancer.