Re: Auto tool changers

--- In CAD_CAM_EDM_DRO@y..., "Smoke" <smoke@t...> wrote:
> Mines going to be a stand alone unit driven by hard wiring. I
don't think
> the unit needs to be programmable. All you need is a signal to the
device
> telling the unit which tool you need.
>
> Smoke.
>
> > Hi Bill,
> >
> > I can see two ways to implement control of the tool changer. A
> > standalone unit driven by a PIC, or by a "canned routine" that is
part
> > of the controller. I could quite easily add a canned routine to
my
> > code, which wouldn't need the "handshake" that an external PIC
> > controller would require. An offshoot of this effort could be a
small
> > program that would run on a "spare PC". It could a PC with only a
> > floppy (or solid state disk), no monitor or keyboard. As small as
> > possible. This is kind of a "black box" approach (good way to
try some
> > of that out). If a keyboard and monitor were supplied, a
parameter
> > screen could allow "tuning" the way the tool changer worked
(positions,
> > travel past stops, stepper parameters, etc).
> >
> > The PIC version is what I think you are interested in from
previous
> > conversations. The PIC controller would only need a pb or so, and
> > perhaps a few LED's. The code can be written in C, however there
would
> > probably not be parameters that could be modified. A small LCD
screen
> > would indeed be possible, but would add to the complexity.
> >
> > What stepper driver are you planning on using? You could cobble
up a
> > unipolar drive. Four TIP120's, a 10 ohm power resistor, a 7400
gate,
> > and a 5V regulator would be about all you'd need.
> >
> > Do you have a stepper bolted up to the tool changer? If you do,
you can
> > try moving it with a controller program. This would determine
worm
> > screw ratio, gear ratio, etc. What we're interested in is the
number of
> > stepper counts for a full revolution of the tool changer head,
and how
> > far past the positions we must travel.
> >
> > Alan KM6VV
> >
> >
> > wanliker@a... wrote:
> > >
> > > In a message dated 2/23/2002 11:17:44 AM Mountain Standard Time,
> > > KM6VV@a... writes:
> > >
> > > > I am doubtful that the ratchet/paw mechanism on
> > > > the tool changer would allow reverse rotation for anything
other then
> > > > "falling back" against the paw, and thus "shortest path",
while
> > > > interesting, may not be allowed.
> > > >
> > >
> > > this is a correct assumption rotation is advance to position,
reverst to
> lock
> > > into indexed/cutting position
> > >
> > > > From index, rotate 140 degrees,
> > > > then fall back 20 degrees. How about videotape? Or a movie
file?
> > > >
> > > >
> > > With six tool positions it would be 60 degrees plus that
required for
> the
> > > ratcher bar to fall. Then back that amount of overtravel plus
maybe one
> or
> > > two degrees to insure stepper stall.
> > >
> > >
> > > > The controller can wait for the
> > > > M6 line "tool change" before the part program is allowed to
continue.
> > >
> > > Don't forget to move the cross slide back to a tool setting
position,
> away
> > > from any work in the unit incase you don't have all tools
exactly set
> right.
> > > EMCO used a microscope to set all the tools to the same
positions aimed
> at
> > > the tool points using cross hairs.
> > > I will look up the site and send it later.
> > >
> > > Hope all of this helps.
> > > bill
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> >
> > OFF Topic POSTS: General Machining
> > http://www.metalworking.com/news_servers.html
> > http://www.metalworking.com/news_servers.html
> >
> > Post messages: CAD_CAM_EDM_DRO@y...
> > Subscribe: CAD_CAM_EDM_DRO-subscribe@y...
> > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@y...
> > List owner: CAD_CAM_EDM_DRO-owner@y..., wanliker@a...
> > Moderator: jmelson@a... timg@k... [Moderator]
> > URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> > bill,
> > List Mom
> > List Owner
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >