Re: Home/Limit switches : Micro switches mounting strategy.

Thanks everyone for the replies. I have decided to go with micro
switches due to simplicity and the anecdotal reports that they
are "good enough". If I can get home within probably half a thou
that would be more than good enough for my purposes.

Proximity sensors sound interesting, but I'm at the stage of the
project where I'm getting antsy to make it do something! ;) Perhaps
this will be a future addition if I don't like the performance of the
micro switches.

Now I have another question with micro switches. Do you guys
recommend mounting them so that the carriage actually runs into the
switch or do you mount them transverse so that a tang or a cam will
actuate them as it sweeps by.

I'm concerned that mounting them so the carriage runs into them will
somehow eventually keep going right through them and smash them to
bits. Also, since my machine is a 3 in 1, many different functions
are performed. e.g. The carriage is much further towards the lathe
spindle when turning and much further towards the mill head when
milling. I thought the flexibility of having a seperate home for
milling versus turning could be handy, but would require switches
that could be "run past".

I'll be sure to post pictures when I'm finished as I'm pretty proud
of how my servo mount adapters have turned out. I'm still at the
stage of machining where if a bolt pattern and milling operation line
up and actually fit the part I'm a little amazed. I couldn't help
but think while I was machining my adapter plates last night how much
easier it would have been to make all three if my machine were
allready CNC.

Thanks in advance.

-Erik Reikes

--- In CAD_CAM_EDM_DRO@y..., w.higdon@a... wrote:
> Erik,
> I would use Microswitches, as an optical switch could be
> very sensative to dirt. I've had problems with high
> speed computer printers using optical switches when the
> photo detector openings could get covered with paper
> dust.
> Bill Higdon
> > I am slowly but surely progressing on my servo CNC conversion and
I
> > have come to the question of limit switches.
> >
> > Are most people using micro switches or optical interrupters to
> > determine their home position? What kind of repeatability in
home
> > position is required/attainable?
> >
> > Micro switches seem like they would be easier to implement while
> > optical interrupter probably have greater accuracy and no moving
> > parts. Right now I am leaning towards optical interruptors with
a
> > small tang mounted on my table to trigger the interrupter, but
> > thought the list might have some thoughts on why microswitches
are
> > the greatest thing since sliced bread.
> >
> > TIA
> >
> > -Erik Reikes
> >