Not sure if I have the setting correct. Went out and took some sample readings on one machine. I strobed the motor for rpm and came up with 1788 but when I review the data and click on the peak, the software is showing 1800. (Ref attached file). In the pic, the peak that is selected would be the 1X of the motor. The next peek to the left would be the 1X of the blower. It seems like the displayed values are rounded??? Any pointers?

Thanks,

Doc1.pdf (26 Kb, 35 downloads) Sample peak

Torsional vibration in electric motors are reflected a t 1X LF or multiples thereof. Just to mention. (Ref- Victor Wowk)

Xracer,
Try the ctrl+p short key (jump to peak function).
Or use 3200 lines instead of 1600 (if racer can wait patiently).

Arie

Xracer,

Agree with Arie. You do not have enough resolution. 70 order 1600 lines or better is required. There's a calculation you can perform based on the minimum frequency you are trying to distinguish. See how you go first. Rgds.
p.s. also if you divide 1800 by the order value you get close to 1788 rpm. You need to correct the speed but fundamentally you need more resolution.

quote:

Originally posted by Vibe-Rater:
Xracer,

Agree with Arie. You do not have enough resolution. 70 order 1600 lines or better is required. There's a calculation you can perform based on the minimum frequency you are trying to distinguish. See how you go first. Rgds.
p.s. also if you divide 1800 by the order value you get close to 1788 rpm. You need to correct the speed but fundamentally you need more resolution.

The original capture was done with 1600 lines of res. When using machine builder, it will set the parameters at 400 or 800 lines ( If my memory is correct) I go back and edit them to at least 1600 lines. After looking over the setup, I was a little confused on how the accelerometer sensor should be set up. (see the other thread that I started in this section). I did not have the drive current enabled in the set up, so all the data will be garbage. I have made the necessary changes, with the exception to one other setting. (See other thread >>> Sensor Thread ), but I'll take some more data to see how it looks now with drive current on...

X-Racer,

If you look closely, the display on top reads 1,007 orders. 1800 / 1.007 = 1787.4 rpm which would be pretty close to the speed you have on the bottom.

Other pointers:

Ctrl-P (locate peak) OR double-click on the peak, this will usually move the cursor to the correct peak.