Interesting topic on reducing vibration

[kieranar]

I have been looking at different material to absorb vibration on FBL controllers e.g skookum came across the topic .

http://www.diydrones.com/group/arduc...olate-apm-from.

Amazon sell most of the materials so I'm going experiment , just orders moongel pads , worth giving it a try.

[cjcj1949]

You need to increase the mass of the item you are trying to decouple. Any passive anti-vibration scheme reduces the forces acting on the mass. More mass less acceleration. Worked for Newton. F=ma or a =F/m

[kieranar]

Interesting topic on reducing vibration

Agree but this only applies with Newton 2nd law if the inputs remain constant , given vibration could be a result of a particular resonance, Then you would look for ways to dampen or isolate theses elements . Increasing the mass is one are I would like to limit.

[cjcj1949]

No. The resonant frequency is a function of mass, and spring rate. Unless you are talking about the resonance of some other part. The mass of the control unit on its own will be low and so you will not need much mass to change the overall mass by a lot. The damping agent must absorb energy.

[Red3]

problem is by trying different tape your not reducing vibration but masking the problem

[scallybert]

problem is by trying different tape your not reducing vibration but masking the problem

I agree with you; and the fine SK-720 people on the HF SK forum know lots about the great tools the accelerometers provide for tracking down vibration.

However, a change to pads might mean you can just go fly - which is why gyro manufacturers have supplied pads and weights for many years...

BTW, the pads are effectively a soft spring and damper in parallel. This interacts with the mass of the FBL (plus additional weight). Varying the weight does have a crucial effect on the response, just as the pad properties do. I doubt that either have an effect on the 'input' (ie vibration of the heli as a whole.)

They may, however, have an effect on the FBL performance. You may not just damp out vibration, but blunt the way the FBL moves with the heli (to some degree).