Hi and Z reset switch

[spiyda]

Hi,

I've just aquired a non-working RV4s and I don't have any documentation other than that I've seen on this forum.
The first issue I have come across seems to be a non-working Z Axis Limit Switch
When I try and run anything the software throws me a "Z reset switch not found"
Investigating it looks like the jobby is a four wire mechanically operated optical switch
Of the four wires that connect it, one pair appears to be +5V and Ground (which I assume is the LED power)
The voltages on the other two ( 0V and 4.78V) don't change when the switch is manually activated
so I assume it is indeed faulty

my questions...
is it just a simple opto switch inside?
can it be repaired or are they still available ?

Chris

[spiyda]

I've actually found an omron component that could be a match...
is the original a phototransistor output ?

[phonoplug]

There was a similar thread about this a while ago, though I don't know if it provides any new information:

http://electricstuff.co.uk/forum/index.php?PHPSESSID=48b244ee2d206cc329b5f8996d1afe0a&topic=52.0

[spiyda]

I don't normally answer my own posts, but I wanted to see this machine at least move.. !

I just simulated the electrical characteristics from the data sheet of the replacement part I found and connected to the arm control board..
It moved !!  (the first time it moved since I got the machine.. )

Still some issues with it getting lost during the warm up procedure..  but at least that means the part I found is either identical to the original or at least a usable replacement.

The part number is an Omron EE-SA105 it is a current part available from several suppliers..

I will post again when the new part is on the machine.

Chris

[spiyda]

Just to confirm that the Z axis reset switch can be replaced with the part mentioned
an Omron EE-SA105

However, whether it was due to a previous alteration of my particular machine or some other reason,
I had to switch the anode and cathode of the LED pair of the opto switch around to get it working.

It is now installed and functioning happily.