Re: Servos and Controller boards

Lee, I think you have some mis-conceptions about the servo motors
used in CNC. They are like any other motor, they go around and
around, no hacking needed. They are not like RC servos and most are
much larger. They have some type of transducer (resolver, encoder,
etc.) mounted on them that gives positional feedback. A drive/amp is
used to power/control the motor. The drive/amp takes commands in
analog or digital form from the motion controller and generates the
appropriate signals to the servo motor. Command input is usually one
of velocity, position, or torque. I hope this helps a little.

~petev

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Trend" <fredit@c...> wrote:
> hmmm. Once I do a hack to make a servo go around and around, I will
loose
> the benefit of servos: the ability to have exact movement, and if
the
> movement is resisted against for a moment, it will keep trying to
move to
> the next position?
>
> thanks for the help!-lee
>
>
>
> ----- Original Message -----
> From: "Greg Nuspel" <nuspel@t...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Saturday, April 10, 2004 7:34 AM
> Subject: Re: [CAD_CAM_EDM_DRO] Servos and Controller boards
>
>
> > I take it you are hacking RC servos. For the lead screw servo you
will
> need
> > to drive the potentiometer usually connected to the servo output
gear by
> the
> > position of the item you are driving. If you don't want
proportional
> control
> > you can disconnect the potentiometer from the drive train and you
will end
> > up with a forward reverse control on the lead screw without
position feed
> > back.
> >
> > If I misunderstood the question please disregard the ramblings.
> >
> > Greg
> >
> > ----- Original Message -----
> > From: "Trend" <fredit@c...>
> > To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> > Sent: Saturday, April 10, 2004 1:55 AM
> > Subject: [CAD_CAM_EDM_DRO] Servos and Controller boards
> >
> >
> > > Hello again.
> > > I am looking to build a new project. This project will need 2
servos.
> > One
> > > that will need to drive a ballscrew or acme (hacked servo), and
the
> other
> > > servo would only need to rotate 90degrees (so a non hacked
servo).
> > >
> > > Firstly, where would you'll recommend to get nice servos from
(I would
> > like
> > > 100oz+ torque)
> > >
> > > And secondly, where should I look to get a controller board?
> > > I found:
> > >
> >
> http://www.jameco.com/cgi-bin/ncommerce3/ProductDisplay?
prmenbr=91&prrfnbr=4152&cgrfnbr=501&ctgys=
> > >
> > > but, does anyone have any experience with this? can this work
hacked
> > ones?..
> > > And i wonder how you control the voltage to the servos on this.
> > >
> > > any help would be awsome!
> > >
> > > thanks-Lee
> > >
> > >
> > >
> > >
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reach it if
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> > http://www.metalworking.com/news_servers.html
> >
> > http://groups.yahoo.com/group/jobshophomeshop I consider this
to be a
> sister site to the CCED group, as many of the same members are
there, for OT
> subjects, that are not allowed on the CCED list.
> >
> > NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY
POSTING THEM.
> DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
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> > List Mom
> > List Owner
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