Rotary Balancing

[RL]

I fear that you are getting a lot of noise from your bearings or the contact point between the bearings and the shaft.  Perhaps a FFT of the signal would give you insight.The only way to cope is good noise filtration though precision bearings do help.

If your rotor is light you might get away with using Teflon or even UHMW V-Blocks instead of bearings.  I had some challenges with this because the rotor weights 6 Kg and appeared to result in a noise that was about 8 cycles/rpm. I suspect my point load was too high.

Are you also using a Banner laser sensor?  You have lost me with the "taps"

On the first balancing run the out of balance signal should be quite strong therefore since it dominates everything else it is easier to fix the position.  The noise level will be fairly constant (I got sawtooth rather than sine) therefore as the rotor balance improves the noise becomes relatively stronger and it is harder to determine where to apply weights.

Raymond

[peper2001]

Thanks for your reply.

I'm not a signal processing expert but, from what i know, the number of "taps" of a passband FIR filter is related to the amount of attenuation in the stopband. If I increase the number of taps, I get a better noise cancelation (but I increase computation time).

I've finaly managed to get good balancing results by modifiying the type of filter. Now, I'm using a IFIR filter wich is a filter designed to create a very narrow passband. It works very well but it's time consuming.

I've also drastically increased the number of averaging!

Bye

[411051]

Hello,

I am also interested in doing single plane & Two plane balancing using compact Daq & NI module 9034. Pl. guide me to select Laser tachometer (manufacturer/dealer), wheather we can use tach. directly with 9034 module?

Sam

[411051]

Hello,

Sorry It's 9234 module.

Sam

[RL]

I use a Banner QS30LD laser to indicate my 0 degrees.   I also have an IR transmitter/receiver that works quite well and is readily hooked up to an oscilloscope.

Raymond

[411051]

Thank You Raymond,

Pl. guide me to procure it (manufacturer's site id).

Regards,

Sam.

[RL]

Sam,

Banner Engineering site is at   http://www.bannerengineering.com/en-US/

If you Google QS30LD "Banner Engineering" you will find various distributors.

Raymond

[AnalogKid2DigitalMan]

Ran across this on the Dev Zone, 2 plane balancing code using Sound and Vibration Suite with a USB based (USB-9234 or similar) DSA card:

http://zone.ni.com/devzone/cda/tut/p/id/12500

-AK2DM

[411051]

Hi,

Pl. guide me for Single Plane Balancing.

regards,

Sam

[Josh_L1]

Hi 411 051,

I’m not very familiar with single plane balancing. A search through our internal database hasn’t turned up anything useful. I’d only imagine the math might be simpler with single plane balancing. I will get with our high precision team and see if they’ve come across anything like this before.

Josh L.