Hi I'm experiencing some TBE with my brand new CX2. It looks like I'm having some tracking issues with the top rotor blades but I've been unable to compensate for it properly by adjusting the linkage to the flybar. Also I don't think I'm having any friction problems with the connections between the flybar and the rotors.

I haven't gone so far as to attempt to balance the rotor blades but I'm hoping that any minor imbalance on the rotor blades would not be sufficient to create this effect.

Now if I take the flybar of and roll it on a flat surface it's obvious that there is some warp to the flybar.

Does this matter with the flybar or is it simply sufficient that the flybar be balanced?

I never balance my rotors. I don't notice the difference on it compared to larger rotors. It is important that the flybar is straight. If it is bent just bend it back to it original shape.

If the blades are off enough to prevent the shafts from running true, they knock the flybar out of true at speed. The shake of a heli can prevent the flybar from doing it's job. Some balance blades and some don't, but the more true the heli runs, the better it all works. Perfection is not required. If it's got a bad shake, that will bind the flybar at the rpm the rotor spins when it flies.

If you can't get the rotors to track even though they are balanced, they may be warped. Search for warped rotors on the forum. We have been boiling them for 5 minutes to get them to return to the original shape.

Good luck.
Soloboss

After soloboss's post for the hell of it I took the rotors off boilded them and then checked the balance. Sure enough the top rotors were way off. Basically I had to put tape all down the underside of one of the blades to compensate. I can't believe it but that was definitely the majority of my problem. It still will only hover in place with only left stick movement for about 4 or 5 seconds before I need to use the right stick a bit but it is WAY better than before. I'm guessing it's likely that if I go back and redo my previous tweaking steps, flybar adjustment etc, that I will be able to get it even more stable.

That blows me away. I mean out of the box it was completely unusable and the main reason would seem to have been the condition of the rotors. That's pretty nasty. I'm guessing a lot of people would have just tried to return the heli or just put it in a closet somewhere and forgotten about it...

Here are some links for you to check out.

Soloboss’s Guide
http://www.heli-max.net/mediawiki/in..._and_CX2_Setup

Eat2muchrice’s Warped blade test
http://youtube.com/watch?v=_7PwNTXOWMs

My rotors were all balanced fine out of the box. BUT, when I broke my first one, and replaced it with one from a new pack? It was NOT in balance with the other, non broken blade. It was waaay off. (different production dates I assume). Anyways, I took two new blades out of the same pack, balanced them, and found that both were already perfectly balanced.

It appears that mixing blades from different packs can lead to an imbalance issue. Just from my experience anwyays

Check the scribed mold number on the blade near the hub (1,2,3,4,) if they don't match, neither will the weight of Your blades.

Try to get them out of the same bag, if not, You definately need to balance them. You won't believe how much one can weigh next to another one of a different mold. I've had it where My heli was almost unflyable just grabbing two out of a box of mixed.

Gary

Yeah, that's how mine was.

I'd read all the stuff about boiling the blades, balancing them etc but to be honest I figured it was probably heli fanatics that had to get THE perfect hover. Keep in mind I'm new to this. I never figured it would be a legitimate concern.

I can see the blades being a bit warped, cool too fast to slow whatever but I would have figured the weight would be constant as long as the molds are all the same.

I'm believer now, that's for sure.

I am new to the CX2 but have been having the TBE problem. I would like to know how to balance the blades.

Thank you,

Mark

As Goldslinger said, it helps to match up the #'s when buying and matching your blades. Here is a picture that shows where the blade #'s are.

The soloboss guide is down so I'll try my best to tell you.
1. use/get two cups/cans or anything with the same height.
2. snap your set of blades together, some say with screws, but I don't.
3. place the ball ends of the blades on the edge of each can/cup.
4. use tape on the end of the lighter blade to counter balance it.

Hope that makes sence.
If not search on youtube. I remember someone made a video of this.

Mark,

Snap together the blades as in the above pic. Balance same using the linkage knuckle between to like soup cans, coffee cups etc. Get a small piece of cellophane tape and trim to fit the end thats high and there you have it! Balanced blades. I have had them bad out of the bag.

Rikybob


"Trust, then verify"

Like Rice said You gotta be quick around here.......plenty of help all over. You guys are great!

Rickybob


"Trust then verify"

That's just it, the molds are not all the same. I use to machine plastic injection molds for Preston Petty Products. PPP was the company that made all the plastic dirt-bike fenders, numberplates, etc. that everyone used back in the 70's.

Molds are finish polished by hand and individual mold cells can vary a few .000" from one to the next. That small amount can cause significant weight difference for something that requires the kind of precision needed for blades on these small helis. If you are a shooter and have reloading scales or some other scale that will measure very light weights then weigh some blades, you'll be surprised.

My experience with four different CX2's (family/friends) definitly indicates changing blades that are significantly different weights causes seriously different flight characteristics from what the prior blade step-up used. Think about that for a minute, if you don't have balanced blades when you first tune your CX2, how can you expect it to fly the same when you break blades and randomly select replacement blades. If you start with balanced blades, when you break one and replace with balanced blades your tune will hold, or at the worst be very very close requiring minimum re-tuning.

Those who claim they never balance blades and their heli always flies the same have been blessed with some kind of "fairy dust" or some other magic

Anybody know where I can buy some of this "fairy dust" that RMG2 speaks of? I googled and found, well, nothing that will help the helicopter. LOL


Sorry all, I'm waiting for parts, so I'm a little punchy......

When I buy a pack of blades I weigh each one and label it. Then I can match them up when I need to replace a blade. I have seen blades as light as 3.9 grams, and as heavy as 4.6 grams. That's a 16.5% difference. You would never guess that they can vary that much, but they do.