I'm new to helicopters and recently picked up a Blade CP Pro. I know this may be a slow learning curve for me so please be patient.

When I power up the main blades there's a heck of a vibration until I get to about half stick; at that point it still vibrates but is spinning fast enough that it starts to smooth out.
It's got new blades and the spindle(between the blade grips) is not bent. I can see the head assy(?) does not run true; I checked the main shaft and it is straight.

The blades are flat bottoms which I was told would be best for a beginner.

Any opinions/advice would be greatly appreciated.

Thanks,
Tbone

Could If it's smooth while it's flying, I'd just fly it and not worry about it. No sense in making it super perfect if you're just going to make an error and crash it anyways. j/k

Seriously though, it's probably just the dampers (those rubber o-rings and washers) centering themselve during spool up. My brushless cpp with hard damper settings still vibrates a little during spool up, even when it's perfectly setup.

kev

[edit: Since your chopper is used, it might need some lube on those dampers. I use 10,000wt silicone diff oil meant for 1/8 scale nitro buggies. Silicone R/C shock absorber oil also comes to mind. I prefer the diff oil because it's very viscous so it won't get "spun off" as quickly, but really any silicone oil will get the job done and allow your rotor to center itself earlier during spool up.]

Thanks for the input.

I found Radd's write up about learning to fly and am trying to follow it. It seems like when trying to power up on the ground it vibrates a lot and instead of the tail going to the right it goes to the left until you really get the rotor speed up...could be a result of the vibrations.

I'll keep at it and see how it goes, just thought it might be easier to control if it didn't vibrate as much.

Tbone

Will I need to disassemble the rotor assy to lube the o-rings or can I just put some lube in there externally?

Tbone

Not wanting to double post, but I'm not sure if you got my comment on lubing the dampers, since I edited that in a bit late.

Nevermind, I guess you did see that.

It might be hard to get lube everywhere it needs to go without disassembling, since the washers act as shields. You don't have to disassemble a whole lot to get at the dampers though. Just remove the blades, remove a blade grip from one side, slide the shaft out the other side, lube, and reassemble. That's it, 3 screws (oh yeah, the 2 linkages need to be popped off the blade grips to slide the shaft out). Just be sure to take careful notes when you disassemble, since it's critical that those washers and grips get put back the right way. There are flange washers (aka stepped washers) that need to be oriented correctly (small step facing the bearings). If those get put in backwards, you'll have the notorious "stuck collective" problem.

kev

[edit: I noticed you are doing RADDs. That's a very smart choice my friend; IMHO it's the "right way" to learn heli. Just be as strict as you can possibly be about your "punishments". Failure is virtually impossible if you're punitive enough.]

It's late and I'm slow, so now that I thought about it, you don't even have to remove a blade grip. Just loosen a blade grip bolt enough to where you can see the o-rings, then put a drop of oil on your x-acto and carefully let it wick in there. Although it wouldn't be a bad idea to open it up to see if the o-rings are worn and see how many damper washer/shims the previous owner has in there.

Are you saying that the blades aren't tracking in the same plane? That will cause some vibrations. It is normal for their to be a lot of vibration when starting up because the blades aren't in there spots yet. It is a good idea before you start the helicopter to put the blades as close to their flying spot as possible and that gets rid of most of the vibration. Then when they are up to speed they find the correct spot. If you have tight or loose blades it can make it worse. When you push the blades you should feel some resistance, but not a lot. I have heard when you tip the helicopter the blades shouldn't move, but if you give it a light shake the blades should move. Then you have the correct tightness. You could balance your blades, but I never do. Then when my helicopter spools down I can see the screw on top of the head assembly kind of wobble. I think that is because there isn't that much support for the mainshaft on the frame. But it flys great, so I don't worry about it.

Nick

Thanks for the input. The blades track in the same plane when viewed from the side, once it's up to speed. It's the mainshaft/rotor hub when viewed from above that can be seen vibrating quite a bit.

I will try adjusting the blade tension and see if it helps.

Tbone

Nick,

Yeah, I get that same low speed wobble, where you can see the screw and it looks like something is bent. I agree, I don't think the mainshaft has much support, and lets the whole thing kinda wobble at low speeds. As you said, it doesn't seem to affect the way the heli flies, so I just don't worry about it.

Glenn

Thanks for all the info.

Well, I disassembled the head, cleaned and lubed it all up and reinstalled it.
While it was apart I leveled the swash plate. While messing around with the swash plate adjustments I noticed that if it was tilted full right, left or back it would bind against the main shaft.
To cure this I moved the servo links one hole inwards on the servo arms and now the swash plate is free in all positions.
I hope that makes sense.

I put the whole thing back together and tried it quickly tonight; it definately seems better but the blades are not tracking the same. I'll try and get that sorted out and see if it gets better.

Tbone

It sounds like your CPP is getting better.

Nick