Re: [CAD_CAM_EDM_DRO] Re: Video of my resonance

Hi Jack C.

I am using the 20 degree rack and pinion, you told me to use that stuff originaly.

I have loosened the the spring and the noise got worse.

I have got it down to the fact that I simply need more reduction. In the order of 10:1 no the 2.57:1 that I have now.

Peter

----- Original Message -----
From: jcc3inc
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Tuesday, September 26, 2006 7:42 PM
Subject: [CAD_CAM_EDM_DRO] Re: Video of my resonance


Mr. Aplais,

Are you using 14-1/2 degree rack and pinion or 20 degree stuff?
We always used 20 degree as it runs smoother.

As an experiment, you might try loosening the spring tension to the
point where the motor just barely drives the carriage; if the vibration
decreases, you have gained some information. You could also
mechanically set the pinion-to-rack spacing (as a test) so that there
is just a few thousandths of lost motion and thus eliminate most of the
pinion-rack "stickiness".

A second approach would be to vary the pulse rate thru the offending
frequency range so that you can establish the frequency at which the
max vibration occurs. Program a linear move on the bad axis and use the
FR override to vary the frequency. As an alternative, you can program
the linear move with a series of identical moves, increasing the
feedrate for each successive move. This involves the F command as you
likely already know. I assume your CNC has lookahead so that you do not
slowdown at the end of each block, all of which are in the same axis.

Regards,
Jack C.

> Dave,
>
> Yes I will have to get a larger pinion, as it will be smoother.
Actually it isn't too bad now. The main reason why I have used a
smaller pinion rather than the proper larger sized pinion is so that I
could make advantage of more reduction.
>
> John,
>






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