Proximity Switch for Z Axis

[randy]

I have just finished a couple of weeks testing an inexpensive limit switch on the Z and A axes of my PRT 4G. I no longer have the problem of raising either of them too high -- no more gnashing of gears immediately followed by the gnashing of my teeth.

The device consists of a magnetic reed switch (thanks Jim Frost) and a rare-earth magnet. Since the proximity switches operate in a normally open condition, they can be spliced into the harness of the existing proximity switches on the Y axis. It it not necessary to do a home-run all the way to the control box.

Once the positions of the switch and the magnet were finalized, I attached them with flexible CA glue.


8144

[dray]

excellent!
How are you wiring it to stop? Directly to stop button or?

[rhfurniture]

Or my low tech version:

8145

[randy]

Danny,

It is wired into the proximity switch cable. I cut the existing wiring a couple of inches from the end of the shrink wrap and spliced the new switch onto the black and the green wires -- the red wire in the prox cable is not used (this modification does not require power). The switches are wired in parallel so that any one of them closing will trigger an alarm condition. If you are queasy about cutting into a perfectly good cable then a home run back to the I/O blocks in the control box is an alternative.

Just about any normally-open momentary-contact switch will work here. I like the magnetic switch because it can be positioned just about anywhere and can be easily adjusted until you get it "just right".

[dray]

THX