Re: [CAD_CAM_EDM_DRO] Re: Rotary Axis home and/or limit switches

For most work, no limit switch is required on the A axis since it should be
able to rotate infinitely without obstruction. However, if you are running
something like a 5th axis setup where the A axis would crash into the table
if the B axis rotates too far, then you wouldn't have
the continuous rotation issue and could run the limit switch.

On Mon, Feb 8, 2010 at 01:01, Roland Jollivet <Roland.Jollivet@...>wrote:

>
>
> The issue everyone is missing, I think, is that the OP's table goes round
> and round and round, and everytime it does, the home/limit is triggered.
> The
> ability to home is not a problem.
>
> But he has configured Home as Limit, and that is the problem. He has not
> replied though, so we cannot know.
>
> If a limit switch is required, but has a complex relation to other axis, I
> think the easiest would be a Pic controller or PLC. Otherwise another any
> old junk PC running Qbasic and interfacing to the parallel port.
>
> Roland
>
> On 8 February 2010 01:37, Torsten <torsten@... <torsten%40gte.net>>
> wrote:
>
> >
> >
> >
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com<CAD_CAM_EDM_DRO%40yahoogroups.com><CAD_CAM_EDM_DRO%
> 40yahoogroups.com>,
>
> > "ya_nvr_no" <yanvrno@...> wrote:
> > >
> > > I have added a couple of rotary axis's But am having an issue with
> coming
> > up with a good way to home them. One switch gives me a home position but
> if
> > I rotate one revolution the switch is made again. I am using CNCpro, it
> uses
> > a limit switch as the home switch.(would another program handle this
> > better?)
> > >
> > > So for example, an issue on the B & C axis.
> > > Do I home at somewhere >90 degrees then move the B axis to the vertical
> > position once I know what that angle is? Manual Zero this location.
> > > Home the C axis and then rotate it ~180 to find the center of the
> > truncated 360 degree rotation? Manual Zero this location
> > > And on an A table axis I would be limited to less than 360 degrees.
> > >
> > > My options are:
> > > Using a M code or manual toggle switch to disable the homing/limit
> > switches after homing
> > > or
> > > Using both home and limit switches, create a logic IC circuit/or PLC
> that
> > determines conditions.
> > >
> > > I've searched but find no info on how this is handled.
> > > There has to be a straight forward way to handle this.
> > > Thanks for any HELP/Direction
> > >
> >
> > This is usually entirely up to the controllers Software how homing is
> done
> > on the Rotary Axes.
> > The Software I am using will look for the trigger of the Switch for
> Homing
> > only when specificly executing a homing move.
> > Then the following happens.
> >
> > 1) Check is trigger is allready pressed. Go step 3 if true.
> > 2) Rotate fast as configured right or left untill trigger actuates.
> > 3) Backoff trigger in reverse slowly untill trigger breaks.
> > 4) Backoff aditional distance as configured fast and set
> > machine zero for the Axes there.
> >
> > Durring other Machining moves this trigger is ignored.
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]