Re: Geckos, Servos, VFD and twitching on Z axis

We have some filters that we are going to try. We are also thinking
about powering our DC power supply via a separate external 110VAC
and then using our 220VAC 3ph just for the VFD and spindle motor.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "JamesCullins"
<james_cullins@s...> wrote:

> Try this one
>
> www.digikey.com
> PREO EMI Filter
> PN: 20EB66
> Digikey PN: 364-1010-ND
>
> Jim
> ----- Original Message -----
> From: "Mariss Freimanis" <mariss92705@y...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Sunday, November 21, 2004 8:23 PM
> Subject: [CAD_CAM_EDM_DRO] Re: Geckos, Servos, VFD and twitching

on Z axis

>
>
> >
> >
> > Your spindle motor drive is an enourmous noise maker. Isolate it

with

> > an RF line noise filter (Corcomp or similar). It will make all

your

> > troubles go away.
> >
> > Mariss
> >
> > -- In CAD_CAM_EDM_DRO@yahoogroups.com, "Raymond Heckert"

<jnr@a...>

> > wrote:
> > > How close to the Z-axis controller to the VFD? Maybe the
> > > electrical 'noise' is causing problems. Are you using the
> > > quill as the Z, or are you raising & lowering the table to
> > > effect a Z-move? Is your ram rigid enough to prevent it's
> > > movement under power? Does the 'drifting repeat itself
> > > with any kind of regularity, under load? These are all
> > > things I'd take into consideration in troubleshooting.
> > >
> > > RayHex
> > >
> > > ----------
> > > > From: yethdear0 <da-mack@e...>
> > > >
> > > >
> > > > Hiya,
> > > >
> > > > We have an old Hurco knee mill that we have stripped and
> > > retro-ed
> > > > with a pc, CNCPro, Geckos and a Baldor VFD for the
> > > spindle motor. We
> > > > just got it all up and running but have a problem with
> > > the Z axis
> > > > servo or controller. Using a travel indicator on the Z
> > > axis, the
> > > > movement is smooth and exact. We have the machine running
> > > a program
> > > > that move Z -.100" pauses for 1 second and then moves Z
> > > +.100" and
> > > > then runs in a loop. When we turn on the VFD and the
> > > spindle, the Z
> > > > axis seems noisy and the travel on the indicator will
> > > start to
> > > > drift .001" to .005" each time the program cycles. The
> > > drift is
> > > > random, sometimes positive and sometimes negative but
> > > positive the
> > > > majority of the time. When we slowed the motion to 1 ipm,
> > > you can
> > > > see the motion twitch at random during the movement. This
> > > only
> > > > happens when the spindle is running and only the on the Z
> > > axis. We
> > > <snip>
> >
> >
> >
> >
> >
> > Addresses:
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