Rotary Balancing

[RL]

Have a look at Conrad Hoffman's spreadsheet on the PM forum.  There are two pages.

http://www.practicalmachinist.com/vb/general/spreadsheet-balancing-181139/

Raymond

[Midlothian]

Is there any news on this topic from the applications team?

I had hoped that this might be included in the sound and vibration suite.

[Andrew_B]

Hello Midlothian,

This is Andrew Brown, an Applications Engineer from National Instruments. There is an example online called Two Plane Balancing Example with DAQmx that performs Rotary Balancing using the Sound and Vibration suite that is referenced in an earlier post. Does this example match the type of Rotary Balancing that you are hoping to perform? 

Regards,

Andrew Brown

[RL]

Gee, having to buy a Sound and Vibration suite and either a USB 9234 or a USB 4432 DAQ is hardly a viable option unless a person already has the equipment and software.  Balancing does not require DSA grade boards to achieve G .4 level results.  A  Labview controlled 200 K samples/second DAQ board should be sufficient for a two plane balance.

[Midlothian]

Hello Andrew,

I had already tried that. Unfortunately there appears to be a "bug" and it fails (on labVIEW 2010) as soon as you select any button.

The message is relating to DAQmx timing error. I was using a 9233 USB module with accelerometers and an analogue tacho all BNC.

All the signals are displaying correctly on signal express.

I bought the toolkit (suite) and I was a bit disapointed to find that even the order-tracking examples for DAQmx have errors reporting magnitude and phase.

(The phase angle was being reported as >10e4 !)

I could use an external math software to culculate the influence vectors if I could reliably get the magitude and phase vectors (relative to the tacho trigger).

I would prefer to use single-plane balancing because I already have the location of the out of balance and I am tuning a single couterbalance disk.

Any further help would be gtreatly appreciated. 

Thanks,

Alistair

[Midlothian]

Hello Andrew,

(The phase angle was being reported as >10e4 !) This could be other high frequency vibration dominating the fundamental order - other tools would report s/n error.

The rpm is correctly calculated, so it may just need some low-pass filtering to solve that issue?

I would prefer to use single-plane balancing because I already know the axial location of the out-of-balance and I am tuning a single couterbalance disk.

The two-plane method requires two experimental steps - each of these would require a two-day strip and rebuild of a large radial-piston pump with internal machined counterbalance (nothing to fall-off !). 

Any further help would be greatly appreciated. 

Thanks,

Alistair

[preston_johnson]

There is a simpler example with raw math that works with a basic DAQ board.  This was the basis of the DAQmx example.  The 9233 has some perculiarities that my be the source of your errors. 

http://zone.ni.com/devzone/cda/tut/p/id/4381

Let us know if this helps. 

[Midlothian]

Thank you for the reply.

This looks like exactly the same files from earlier in the thread (from the 2006 and 2007 dates and file names).

These are the ones that had the error reports in labVIEW 2010 version with 9233 as I mentioned above.

I can solve the equation by vector division using an excel or mathCAD I am familiar with the process.

What are the 9233 issues that you mention?

[Midlothian]

I have had a go looking at the VI in your link.

There are several missing sub-VIs as it loads.

I don't have a NI PDA or the CF equipment so these may be for that hardware.

Thanks.

[preston_johnson]

The missing via are likely daqmx base
You should pull the math and substitute in the DAQ functions for your hw