Re: Estop

There is deffinatly a difference of approach on how an E-stop should
work.

I am of the mindset that the E stands for Emergency, not opErational.

When a milling cutter works loose in a hole and is still in the hole
as the axis starts to move, that is an emergency. clearing some
chips out is not.

With a decent home switch arrangement, re-zeroing all the axis should
not be a lenghty and complicated proceedure. and the computer should
not be on the E-stop circuit.

re-seting parts and fixtures after a catastropic failure in not
considdered normal operation.

OSHA and most companies who think about such things would come up
with the scenario that the e-stop being depressed and an arm in the
machine will not preclude the button from being released with the
other arm or some external thing. reaching for a tool, it slipping
and you quickly trying to grab it comes to mind.

Some good things to think about when you plan such circuits.

also, some trueisms...

you are only as safe as your most unsafe act.

and a machinest may considder safety as being able to count his 10
years on his 10 fingers.

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, wanliker@a... wrote:
> In a message dated 5/28/2003 11:25:13 PM Mountain Daylight Time,
> elson@p... writes:
>
> > Almost all companies, in my
> > experience, leave their
> > CNC controls powered on at all times.
> >
>
> You will find that EStop is not adequate to work on a machine. In
all of my
> years of working, Lock Out, Tag Out has been required to work where
there
> could be ANY danger to the worker.
>
> Guys don't short circuit your safety at any
time............................
> bill
>
>
> [Non-text portions of this message have been removed]