I had a minor crash with my king 2 and all that broke was a link and blades, and feathering shaft of course. I replaced all the parts and it seems like i have a tail vibration that i cant get rid of. I have tracked the blades but to no avail. They are wood blades from ushobbysupply. Is it possible that its the main shaft? It doesn't seem like the head is wobbling. Any help would be appreciated.

Check the Main Shaft, no wobbling doesn't mean not bend, just too minor for human eyes to notice. Take it out and roll it on a hard surface such like glass. I usually only take the whole head set out & leave the main shaft then I throttle up, there you can see precisely is the main shaft bend or not.

If it is fine then adjust your gyro gain.

If both above don't work then go buy a new HBK2, lol joking.

Well i checked the main shaft and its perfectly straight. Could it be unbalanced blades?

Okay well after checking both the shafts in the head, i found no wobble in the head. So i took of the blades and i still have vibrations. Then i noticed something, the main gear is warped. When i look at it when the heli is at low rpm, you can see it going up and down, could this cause vibrations?

Also check the tail shaft, that could be bent and causing vibration. It could also be the main gear, like you pointed out

Michael

Yeah im betting its the gear or maybe theres the slightest bend in the main shaft that i can't see. I know its not the tail shaft though cause i took the belt pulley off and it still vibrated. So a warped main gear can cause vibrations?

I guess a warped main gear could cause this but I would say it is not likely. I have replaced 6-7 main gears and every one of them seems to have the same "warped" like characteristic. My performance does not seem to be compromised. Unless it is so bad that you can see the main gear shuttering just before lift off, I would look elsewhere. Look at the collar and the bearings now since you have tried everything else. Make sure that the collar on the main shaft is snug to the top bearing in the frame and in the correct orientation(rounded side up, flange part down to ride on the bearing race). Also when you check the collar, make sure that you pull up on the head to see how much play the main gear at the bottom has. It should be pretty darn snug against the bottom bearing(1/4mm of play maybe). Check that the bearings are not wasted enough to cause a shutter and the small brass spacer is not missing from between the pulley and the bottom bearing. If any of these parts are wrong, you could have an intolerance that would/could cause a vibration.

Hope this helps, there are so many things it could be....Are your control arms on backwards? Elongated part should be toward the inside of the center fly-bar holder.

Hmm?

Z

Well i think i found the culprit. My flybar is slightly bent so im guessing thats it. Can a slightly bent flybar be causing this problem? I had to roll it on a hard surface to notice it. Oh and i just checked and the main shaft collar was upside down!

Thank you soooo much Zimatosa, that collar did it! Strange though, cause the reason i took everything apart was to try and fix the vibrations.

The way I explained it is actually backwards. In the manual it shows it with the flange on top. This made no sense to me seeing how a bearing race usually wants a flange against the inner race. I just wanted you to know that technically it is backwards and you are now a rebel like me. Some people might flame me for doing it wrong?...(Funflier) Hehehe But I have more success with it upside down...Now I am wondering if the manual is wrong or if I(we) have it wrong...Seems funny cause turning it around fixed a binding problem I was having intermittently. I have been running it like this for 3 months!!

If your problem is fixed as well, I would like to hear others explanations on what the HE77 is going on!!??

Could be coincidental that both our problems were fixed just disassembling and reassembling too?? LOL

Happy Flying!


Z

I fix my fly-bars with my fingers all the time. make sure that the paddles are running true after you are done bending and tweaking!! I even used a fly-bar that looked like a pretzel and it worked great....They are fairly cheap as well if you can't get them just right...

Z

Im pretty sure it was the collar. No idea why it didn't affect the heli before i crashed it. Thanks again!

Well took it out today, and was flying a very mild circuit, when i started to lose power. I landed fairly soft though, no damage. However when i took off again, the vibrations were back and worse than every before![:@] Upon closer inspection i noticed the motor itself was vibrating. So i grabbed the outside of the motor and pulled softly to see if there was play. To my surprise i found that the entire top piece can slide up and down! It feels spring loaded, is this a problem? The top piece can be pulled up to reveal the windings but its spring loaded.

It's a outrunner motor thats why you can lift the outer case, If the pinion gear wasn't on it you can pull it apart and look at it! Scared ya didn't it?
Zim what did I tell you about putting stuff together upside down hahaha. Long as it works is what really counts. What works for me may not work for you and vice versa. Interesting enough my original main shaft collar was the same on the top and the bottom (rounded), lasted about 10 flights before the set screw came loose and distroyed the threads in it.
I just want to get my belt to make friends with my rear sprocket and follow it around...

Flier,

Installed the Xtreme stiffener yesterday..Mike just got them in at Cal Hob. Still have no motor because i do not trust those overpriced Common Sense RC motors. Mikes wifey(?) was helping me and said "what about the Esky motors"...Told her I know Mike would tell me the same thing and to install one of those as well, he did....To make a long story shorter...I told them "I would rather burn in hell than install and Esky motor on my King"...Now i am stuck with my principles and no motor....Who else makes a motor like Hyperion with a 23.64mm outer diameter can??? If I go bigger, I will most definitely have to do that servo mod you showed me at the LHS. Maybe just buy what i want and use a 12-13T pinion, then tune her down in the radio? Sorry for the rant high-jack on your thread Brian....

Z