Re: Limit switches revisited

I agree, Paul, although I see a lot of examples where the switch is
indeed the stop. I was thinking I could use a roller-arm switch
attached to the ways that is tripped by a projection on the bed as it
passed by to allow for overtravel. My mill will have limited work
volume and my steppers will be slow, so I don't envision
any "hurtling," but mashing the switches just seems like shoddy
engineering to me.

The same "en passant" technique could be used for detecting home
position with mechanical switches but I'm uncertain how precise and
repeatable it would be.

There seem to be a vocal minority out there in netland who forgo
detecting home position and reference to edges on the work piece
instead. I haven't looked into edgefinding technology.

Thanks for your reply.

Regards,
Kent

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Paul Kelly" <tech@c...> wrote:
>
> For me, the most important characteristic of a limit switch is
overtravel.
> The axis it's limiting must be able to continue to move a small
distance
> beyond the trip point of the switch when it goes hurtling into it at
max
> rapid speed. Small pushbutton switches make poor mechanical stops!