Hi,

Just got a brand new head assembly and tried putting everything together. This time it's like a complete heli setup, with new tail (boom, servo, tail assembly), new cyclic servos, new main gear, new landing gears.

Everything got in place nicely, but what is surprising to see is a major head wobble at low rpm, at around 20% upto 50%, wobble goes out of control when input the main blades on.

Things I have tested so far:
- replaced the main shaft, no difference
- took out the fly bar, no difference

Is it possible that the head assembly is faulty? Off balance?

If people can help understand what to check and how to fix this issue?

Quote... a major head wobble at low rpm, at around 20% upto 50%, wobble goes out of control when input the main blades on.

Not quite sure if I understood correctly, but do you mean there is a wobble without the main blades?

Can you post a video?

Sent via tapatalk

Hi Guys, Yes, let me post a video by evening.

check the tracking of blades
even i had the same problem
will show the video

hi, in my case the head wobbles even without blades or flybar. Will post a video soon, thanks people this forum rocks.

take the complete head out except for the main shaft... take a marker and mark at the centre of the shaft and run the motor slowly.. check if the mark wobbles.. if yes then the main shaft has an issue and is bent

sujju

awaiting video to correctly understand the issue.

Hi Sujju Sir,

Your doubt about the shaft was correct, seems like the shaft i got with the assembly was not proper. I had a spare one, tried it and it works just fine.

Upon connecting the blades, i found the they were out of balance, balanced them, but had to use a lot of tape. If anyone can confirm about this much amount of tape is ok to be used (check the image) or i should buy a new set of blades?

Hi,

It is not uncommon for the blade set to be quite out of balance at times. The amount of tape does add considerable amount of additional weight, resulting in low efficiency. You may choose to get another set of blades (preferably Carbon Fibre).

Amit K

Quote from: dheerajjuneja on August 07, 2012, 09:36:56 PM
Your doubt about the shaft was correct, seems like the shaft i got with the assembly was not proper. I had a spare one, tried it and it works just fine.

In your first post you mentioned that you replaced the main shaft with " no difference" which is contradictory to the statement above.

and I agree with Akumar40 go for CF blades.

heliflyer, yes, consider it bad luck, i had tried two shafts, one that came with the head, and another i had spare ( one of the three from hk shaft pack ), third one worked fine.

thanks for the suggestion for cf blades, the one i have are also cf, but they came dis balanced it seems.

once they are balanced, they should be fine i guess? i wont be too bothered about the efficiency if it means faster cyclic response or flight time per charge as all i would be doing for some time is hovering and orientation practice. however, if you are pointing to something else, then please let me know.

Hey,

Thanks for clarifying, looks like the ones you have are glass fiber (GF)  as generally Carbon Fiber (CF) blades are balanced. There is no harm in applying that amount of tape (considering you balanced the blades properly) for the level of flying mentioned by you.


Hellyflyer