Shaker Load Capability
Shaker Load Capability
(OP)
Hi,
I have a little question. We are intending to use a small shaker (ButtKicker LFE), the supplier was very limited information available:
Frequency response: 5-200 Hz
Nominal Impedance: 4 Ohms
Power Handling: 400 Watts min.
Through the whole range of frequency the amplitude of acceleration intended is: 0,1 g-peak
Based on these information, is it possible to calculate the allowed mass?
Many thanks
I have a little question. We are intending to use a small shaker (ButtKicker LFE), the supplier was very limited information available:
Frequency response: 5-200 Hz
Nominal Impedance: 4 Ohms
Power Handling: 400 Watts min.
Through the whole range of frequency the amplitude of acceleration intended is: 0,1 g-peak
Based on these information, is it possible to calculate the allowed mass?
Many thanks





RE: Shaker Load Capability
TTFN
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RE: Shaker Load Capability
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Shaker Load Capability
just a thought,
cheers,
RE: Shaker Load Capability
That doesn't make sense dimensionally or anything else, and certainly doesn't come up with a credible answer for a 5 inch diameter shaker.
5mm amplitude at 100 Hz is around 150 g rms, is it not? So you'd need a force of 60 kN for your 40 kg mass. That's around 6 tonnes. I've never used a 6 tonne shaker, but I've seen them ,and it would be a 2" dia hydraulic ram, and would not hit 100 Hz.
sidbrazil
0.1g pk at 5 Hz is a displacement of 1mm peak, probably within the displacement limits.
Your spec doesn't help much as you need to define what mass you want to accelerate, not just the acceleration. You also need to know some details of the internals, turning a power capability into a table acceleration is not really practical by guesswork. IRstuff's equation is more along the lines of how much power would be needed for a certain mass and velocity, as a MINIMUM, it would be a very optimistic estimate for any commercially available system.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Shaker Load Capability
Ok I will not contradict you here. Maybe I misunderstood the question. If so, maybe you can enlighten me.
I don't know any specs about the shaker in mind, I assumed that the maximum energy it needed to produce is to lift that MASS (in the face of gravity) in a particular time of 1/100s. And so, I assumed F is just F=mg. I just converted the energy required to lift a MASS a distance I just made up (5mm) into power. Done deal 5 second calculation.
Whether this information is valid for the particular case I don't know. But from the information provided, with an added parameter of distance it is possible to estimate a MASS (like I said, based on it being able to lift this MASS in the face of gravity in a particular time period)
I treated it like a basic physics problem. I know that in order to obtain a credible result we would need more information about the device I just did what I though might help.
Is there something I misunderstood? If so, please let me know.
Regards,
Coppola
RE: Shaker Load Capability
These help the situation:
A*(2*pi*f)^2=max accel.
Power=Re(F*v(w)), where v is the Fourier spectrum of the exciter velocity
cheers,
RE: Shaker Load Capability
http://www
I doubt that it would come close to 1g with no load on it.
Jim Kinney
Kennedy Space Center, FL
RE: Shaker Load Capability
Here is the deal:
We are designing a mock-up for confort assessment. Due to commercial and practical aspects, we are using the Buttkicker shaker. What we are looking for is to create an vibro-acoustic atmosphere, and we are not so worried about amplitude precision.
Eventhough, we want to assure a 0,1g-peak of amplitude at least.
The manufactures has no information regarding eletrical to mechanical efficiency, and dynamic capability. Probably what we will do here is a try-out to figure out the best distribution of the shakers...
Anyway, many thanks.
RE: Shaker Load Capability
If you want to shake something, then you need to get a real shaker.
TTFN
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RE: Shaker Load Capability
I bought a similar product for 20 bucks and found that it was compeletely useless when screwed to a chair - all it did was excite the resonances of the chair, ie musically all it had were wolf tones.
Oh well, the power supply and amp were worth 20 bucks.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Shaker Load Capability
For example:
http:/
I believe you would need more information if you were to dynamically model the system and calculate the mass of course.
TTFN,
Fe
RE: Shaker Load Capability
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Shaker Load Capability
Anyhow, if it were me I would just call the company. There is surely someone that would know the allowable mass.
ttyl,
Fe
RE: Shaker Load Capability
http://www.dynsolusa.com/edshakers.htm
http:/
http://qualmark.com/Products/edShakersModels.html
http://ww
TTFN
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RE: Shaker Load Capability
Fe
RE: Shaker Load Capability
The problem with a chair is that it has a couple of very strong modes (bounce on seat and backlsapping) that are non linear and not particularly well damped. Finding a sensor location that would adequately sense all the modes would be tricky.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Shaker Load Capability
Fe
RE: Shaker Load Capability
Thanks again,as Greglocock pointed, the system is very cheap. We will get a shot down here.
The idea is to have some accelerometer on the foot and also at cushion region in order to verify the amount of vibratory level imposed. We will be controlling by a in-house executable programmed in Labview. If we experience an resonance (by our experience they are to 5 Hz the dundamental one) we could change the shape of output signal. We will spend some time here because this will be a open loop control system. It is not worthfull to create a program for closed loop control.
We are confident that in some level it will works. We've seen similar stuff being developed by Vienna University, Volkswagen and Airbus... keep in mind that the desired vibration level in pretty small.
RE: Shaker Load Capability
If this helps, the supplier indicates a maximum force of 70lbf for the BK-LFE (I believe the inertial mass is 3.5lb). You may be able to use this information.
ttyl,
Fe