Re: repeatable vs accurate switch

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Don Rogers <Don@C...> wrote:

> I am working on a machine design that needs a signal that is

repeatable to

> a very tight tolerance. I don't care if it trips at 0.250" or at
> 0.000250", as long as it is the same each time. My thoughts now

are

> focusing on optical sensors. First is just a plane flag through an

optical

> coupler, and the second is a mechanical amplified version, IE a 10X

gear

> driven optical aperture.
>
> Any pitfalls or ideas that come to mind??
>
> Thanks Don

Every switch should be repeatable unless the switch is broke.
Accurate is largely defined as very fast switching in motion
control.
A table moving at a fast velocity is recieving a move pulse
in microsecond intervals. The switch will have to send the
signal also at a very fast speed to let the controller know
that it has triggered.
Keep in mind that if the object of the switch is to stop motion
that a mass moving can not be stopped instantly but has to allow
for some distance to decelerate.
Find a suitable switch with a fast responds time.
Good Luck