Re: limitswitch set up

Owen,

Sorry I haven't taken any pics yet.

My mill came with a bracket for X spring stops, I bent up a new
bracket to take the box for both X switches which mount in the box
and I just milled a slot for the blades to pass through, I had some
soft hacksaw blades so I milled a couple of slots in them for
adjustment purposes, for X I mounted them on adjustable blocks for
coarse movement. Y & Z switches are mounted on cut down 620
extrusion which in turn is fixed to the knee assembly, the Y & Z
blades are fixed and adjustment is made by moving the switches.

The switches come from http://www.lasermotion.com/Servo.html, they
are listed about 2/3 rds of the way down the page as OPTO LIMIT
SWITCHES, it says $25/16 pcs, but its actually 15 pcs, an excellent
buy IMO. Wiring is straight forward, put 220 ohm resistors in series
with lead 5 to limit LED current, I used 4 wire shielded cable from
the controller to each box, +5, gnd, axis- and axis+, grounded the
shield at the controller end only, The RS boxes come with a PCB which
was convenient for mounting minature terminal blocks the resistors
and a cap across the supply.

Hope this helps,

Bernard

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Owen Lloyd"
<sportbikewest@t...> wrote:

> Bernard,
> would you happen to have any JPG's of your set up? Sounds pretty

straight

> forward but you mention the radio shack boxes are slotted at both

ends?

> Do the blades move with the table with the boxes [3 of them with one
> containing both an X and a Y switch??] mounted to the base?
> Lastly do you have the link for the purchase site?
> Sorry for all the questions but this is my next step in the

Loooooong CNC

> conversion process.
> Owen
>
>
>
> > Jens,
> >
> > I am using fork type opto-switches I bought off the web. Though

not

> > specified they are Schmitt trigger output, repeatability was +-
> > 0.0002, but that might have been my dial indicator. Output is +5
> > going to 0v when the beam is interupted, switch hysterisis is

0.003".

> >
> > Both X switches are mounted in a Radio Shack plastic box with

slots

> > machined in both ends for the blades to enter and I have mounted

felt

> > wiping strips that clean the blades. Y & X switches are mounted

on

> > some cut down 620 extrusion so I can easily adjust position.
> >
> > So far no problems.
> >
> > Bernard