Blade balanace?

[chaos]

I don't think it's a gottahave, but it makes the heli more stable on the pitch axis when moving fast. If you plan to fly without it, check the balance. You can probably make one out of a piece of scrap counter material, or maybe a a spatula like what's used for spreading Bondo on a car.

[hawkman]

You dont need the fin at all....yes it looks good....the tail fin is a good idea to keep the tail blades off the ground.....but like what was said....just make your own.....dont use metal though.....this can vibrate and could cause interference for the radio link....try this...switch your heli on...tap something metal with a screwdriver....watch the servos....they will wiggle...this is because as you strike the metal it gives off a pulse...for some strange reason...which some mere person like me doesnt fully understand

Rob

[shanee86]

Ok thanks I got my heli off the ground again today without the fin and it was ok flying not bad. But it shock alot and was out of trim then I landed it to trim it and then never got back off ground because tail was not working right and spinning abit when giving it gas so took it in and tail wasn't right so fixed that. But it was vibrating pretty bad and when I put a level on my blade on front of heli it says level but when they reach the back or tail part is says not level any ideas? Also when I crashed it broke a pushrod so thinking maybe pitch could be off a bit plus one more little rod end broke today. So I fixed that but just trying to figure why it would vibrate so much I balanced the bladed a bit before I put them on seem fine any ideas?

[chaos]

Hmmm, I suggest powering up the servos and give them a little twist to see if they hold. Perhaps a gear got stripped which would allow the servo to flail around. With servo power on, grab the swashplate and try to rock the it fore/aft and left/right and up/down and see if it holds. Don't be brutal about it but apply enough force to make the servo have to work to hold. Be looking for something cracked - like a bellcrank or mixer lever or washout lever - and giving way when you apply pressure to it. Also hold the flybar still and give the blade a twist (like to change the pitch) and it shouldn't change if you hold the flybar still. Again, be looking for any cracks.

You can have a cracked part that looks just fine with no load applied to it, but it gives way when flying.

Have you put new blades on it? If so, take a careful look at balance. Here's a link.
http://www.helifever.com/articles/1/1/Blade-Balance

You can remove the blades and fire up the engine and run it at maybe 1/4 throttle to see if that fixes the vibration. If so, then that's a clue where the problem is. Don't give too much throttle... without the load of the blades it's pretty easy to rev up too much. If it still vibrates without the blades then the flybar would be a suspect. If you remove all the links to it so it can teeter freely you can see if it's balanced. If the flybar is balanced but the heli vibrates, I'd get despirate and remove the whole head assembly, everything above the washout levers. I guess you have a manual. Here is one if not.
http://www.centuryheli.com/support/m...?currentid=385

If it vibrates with the head removed then maybe the torque tube to the tail is bent. Or maybe a bearing is bad and allowing the torque tube to slop around. You could pull the tail off and run it to see if that's the problem. If it still vibrates then maybe the fan has lost a blade. If that's the case then it will be a pretty high frequency vibration. I'm running out of parts to suspect.

I'd like to know how this turns out. Please let us know.

[shanee86]

I set a level on my head or top of it and it isn't level any ideas? Is that normal? Maybe shat is bent?

[chaos]

I'm not sure that means anything. It depends on how the shaft is related to the skids. A way to tell for sure if the shaft is bent is to remove it and roll it on something really flat... maybe a glass top coffee table, even a window. A bent shaft sure will cause vibration so it's worth checking.

[shanee86]

I am thinking it is the little brass fitting that goes on the feathering shaft. When I crashed it bent the feathering shaft so I bought another and put it on but on brass fitting was still on old one and it was bent bad so I bent it back best I could and then had to still bang on that brass fitting a bit to get it off and so it had a nic in it and that is probably causing the blades to not be real tight or something. But I am not sure see I put the feathering shaft on and tightend the look nuts then it was getting tighter and tighter then it stop tighting so thinking something may be stripped or something any ideas? I tried take the look nuts off again but wont come off any ideas if that is normal because my feathuring saft had threads on so far or how do I get it off lol?

[shanee86]

Well anyway I know or think my pitch is off now after crash. Plus my shaft my be bent I was test flying or hovering it and blades when hover were off a bit. But tail issue is fixed now. So I will be doing some work on it probably.