Estop consids was Re: The 250 byte packet viz. ESTOP

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@...>
wrote:

>
> >In CCED, "ptkeillor3" <keillorp135@> wrote:
> >In any case, I try to anticipate and test for anything that might
> >contribute to an unsafe condition, and design accordingly.
> <snip>
> >At least in the CNC world, when you cut the power everything

stops,

> >so that would be the safest condition.
>
> Pete,
>
> Your first point included above is right on the mark, IMO. (Along
> with the snipped "supporting" text)
>
> But the second one misses some targets, IMO.
>
> If you cut power to backdrive-able axes, and a spindle motor is
> engaged and cutting, it will tend to climb into the work and can
> easily create a mess, chaos--as everybody doves for cover from the
> exploding bit-- or worse. (Not all spindles are immediate in
> stopping...)
>
> Like I said, your first comment is spot-on.
>
> Ballendo
>

Excellent point, thanks. I'll try to make sure I consider it when I
get to my own design.

Pete