# Utilise an optical sensor to collect phase information of the helicopter and then the dc motor?

#### Shaggy74

Joined Oct 20, 2017
36
... and the Wildcat wouldn't fit in you garage.

Have you found a solution for cancelling the amplitude of the vibration?
Once I achieve the equal and opposite of phase for the motor and rc helicopter I will just go about it the long way round by steady adjustment, not ideal but hopefully it will be possible to see a noticeable change until total balance and reduction in vibration

#### joeyd999

Joined Jun 6, 2011
4,477
Why not just balance the rotor shaft with a counterweight?

#### Shaggy74

Joined Oct 20, 2017
36
Why not just balance the rotor shaft with a counterweight?
Because I need to use the motor as a “shaker” to prove I am capable of reducing the vibration of the helicopter

#### joeyd999

Joined Jun 6, 2011
4,477
Because I need to use the motor as a “shaker” to prove I am capable of reducing the vibration of the helicopter
And...

...you cannot prove you are capable of reducing the vibration of the helicopter with a counterweight?

There is not much to prove -- I guess except for your "capability of reducing the vibration of the helicopter".

#### Shaggy74

Joined Oct 20, 2017
36
Wow. It seems there's far more to helicopter vibration than meets the eye.
I am concentrating on reducing the vibration along the vertical line. The largest vibration caused is through the main rotor head due to its movement in all directions when achieving lift or translational flight. I need to design and build a system that will reduce vibration through the overall structure of the helicopter so need to come up with something more than just an additional weight

#### joeyd999

Joined Jun 6, 2011
4,477
I am concentrating on reducing the vibration along the vertical line. The largest vibration caused is through the main rotor head due to its movement in all directions when achieving lift or translational flight. I need to design and build a system that will reduce vibration through the overall structure of the helicopter so need to come up with something more than just an additional weight
I think a vibrator motor would be difficult to tune. If I were doing this, I'd probably try think of a way to use some kind of linear actuated vibrator* (an electromagnet with an axial-moving weight), and use an accelerometer to provide feedback to cancel all of frequency, phase, and amplitude in that axis.

But that's just me.

*Edit: Think in terms of a voice coil.