Re: [CAD_CAM_EDM_DRO] Re: 4th Axis Concept (long)

With the methods below, we would need to get the control software to first
locate the spot, then stop there, Knowing that it is at part 0. I'm not sure
this is necessarily easy or inexpensive to do. It seems that once zero is found
via encoder, then the control software would have to re assign part zero. I
don't think it is possible with the software I would like to make this technique
work with.

I am assuming the Servo when acting as a traditional motor will need to be
powered from an auxillary supply and not thru the Control systems supply chain.
Some Relay work there........I'm not sure how we'd get this lined up using
Flashcut, Yeagers CNCPro, Master5, Kcam and controls as such. This is the market
that it needs to operate in. Given that, it probably should stay stepper
orientated at first. It would be *very easy* to control with an "indexable
clutch" and any typical step/dir control on the market because there would be
nothing proprietary.

Too, with the encoder used as below, the part would have to be indexed
*according to the switch* from the get go, setting zero and then mounting the
stock.

Servo, encoders,.........Seems like a project for the EMC fellows......... well,
after they actually get the bugs out of making EMC work flawlessly !

Chris

jguenther@... wrote:

> It would seem to me that you could us an indexed optical encoder, then you
> could just turn off the optical encoder, free run the servo motor for normal
> turning, then when you needed precise positioning of the spindle, switch on
> the optical encoder, and because it is indexed you could easily find the
> home position and work from there. I would mount the encoder disk on the
> spindle and not the motor, especially if you are using belt drive. This
> would eliminate any slippage between the encoder disk and the spindle. I
> also assume one would need to come to a full stop before changing modes from
> free-run to servo.
>
> John Guenther
>
> > -----Original Message-----
> > From: Alan Marconett KM6VV [mailto:KM6VV@...]
> > Sent: Monday, August 06, 2001 2:42 PM
> > To: CAD_CAM_EDM_DRO@yahoogroups.com
> > Subject: Re: [CAD_CAM_EDM_DRO] Re: 4th Axis Concept (long)
> >
> >
> > Hi Chris, Roger,
> >
> > If you use the servo, and also free-run it as a spindle motor, I'd
> > suggest using an "optical interrupter switch" (or hall effect sw) to
> > "find home". You should be able to switch control back to servo, and
> > "drive" it back to this "home".
> >
> > Alan KM6VV
> >
> >
> > vrsculptor@... wrote:
> > >
> > > --- In CAD_CAM_EDM_DRO@y..., datac@l... wrote:
> > > > In the following explanation, picture in your minds 2 motors
> > > driving a Sherline or similar Lathe spindle, First motor: a dis-
> > > engagable stepper, The Other: A traditional spindle drive motor....
> > >
> > > Chris,
> > > Interesting idea. If I where to do this I would use a servo motor
> > > instead of a stepper. A servo motor with encoder can be controlled
> > > with a Gecko 340 using step and direction input just like a stepper.
> > > When in lathe mode just switch out the controller and apply DC
> > > directly to the servo. You could get the RPM you need without having
> > > to clutch a motor in an out.
> > >
> > > There is still the problem reseting the piece to zero. I think this
> > > could be handled by turning off the power and rotating the shaft by
> > > hand to a known position. A fixed position could be established by
> > > resting an arm, attached at a right angle to the 4th axis shaft, on
> > > the top of a 1-2-3 block or some such.
> > >
> > > Roger
> > >
> > > Addresses:
> > > FAQ: http://www.ktmarketing.com/faq.html
> > > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> > >
> > > Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
> > > Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> > > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> > > List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> > > Moderator: jmelson@... timg@... [Moderator]
> > > URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> > > bill,
> > > List Manager
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> >
> > Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
> > Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> > List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> > Moderator: jmelson@... timg@... [Moderator]
> > URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> > bill,
> > List Manager
> >
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>
> Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> bill,
> List Manager
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/