optical limit switches

[phantomcow2]

Is anybody using these things? I have some I would like to use, but would like to hear other thoughts and experiences on these for this application.

[bgolash]

Hi
I used one on my z axis. I did because I could purchase them
from digikey for about a $1.47. There are a few negatives to using them.
They are difficult to mount due to their design. Finding connectors that
won`t fall off the pins is usually a difficult search. They need a resistor in
series so you won`t blow out the internal LED. After I installed the photo
sensor I then tried npn proximity switches from automation direct and have
been happy with them. They also sell a screw on cable that is very secure.
I used them only as homing switches. It was my assumption that they would
be more accurate then a snap action limit .

Regards Barry

[Bubba]

I also use an optical on my Z axis for homing, and find it to be easy to use (it has internal voltage control) and has only three connections, +5, Gnd, and output (OC).

In the testing I have done, however the repeatablility is very comparable with my mechanical switches.

I salvaged mine out of an old copier! (cost nothing), but I will have to agree with the connector. I salvaged that also, but with the vibration on my mill/drill, there are times that it will "break connection" momentarily and cause a trip as I also use my home switches as limit switches.

[phantomcow2]

Well the ones I have are from SUNX, have 4 wires. I was told what they were, but do not remember all of them. They have 4 wires, I am told they are
Active Lo
Active Hi
Power
Ground

I wa just concerned about wood chips getting in there, and tripping it. Maybe I can set up a little 60mm fan to blow chips away

[Bubba]

I also was worried about swarf and coolant getting in there and messing things up. I attempted to get around this by switch location and shielding. So far, things have worked very well.