Hi all,
Here is a quick post about how I got my Z-zero sensor to work. When I had the original brass puck, it would only contact intermittently. I think this is partially due to the ceramic bearings in one end of the spindle not helping the electrical circuit much. I hadn't actually tried to use the sensor due to others on here breaking tools when theirs fail to sense properly. I took heed of this and tested mine by touching the sensor in the spindle nose manually as the z-axis was descending. The sensor would work every time if touched on the spindle casing but only intermittently when touched on the parts that spin.
What I have done is use the wire that normally connects the the brass puck and used it with a micro switch to connect the wire to ground. The round black thing is the inside of an old computer fan and it has a micro switch inside. The center of the fan motor is removed but the shaft still slides vertically in the original bearings. The flex wire that was supplied with my brass puck is multistrand, so I split the connections and used that for the earthing wire as well as the sensor wire. The earth can be connected anywhere on the structure inside the Z-axis housing.
As you can see from the photos I have made mine with a plug on it, I would NOT recommend this, or if you do, make sure that the socket connections close when the plug isn't inserted. I haven't broken any tools because of it but it has run down too far without stopping because of the plug not being correctly inserted. I just happened to notice this in time and stopped the machine.
I intend to make a new Z-zero sensor at some stage. I will make the following changes.
1, A heavier base so the sensor sits flat on the material without having to physically hold it down.
2, Make the sensor out of metal and not plastic to stop the errors from the flex in the plastic when the tool doesn't push dead center.
3, I will hard wire the sensor into the machine and not use a plug.
4, I am also considering a backup switch inside the sensor for if the micro switch fails (as they all do eventually).
I have also included a basic circuit diagram (done in MS paint
)
Shannon