Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

[Zeeflyboy]

I'm afraid I don't use the same motion controller as you, nor do I use Mach3 anymore... but it should be fairly straight forwards.

Hook it up to the same point that the normal probe goes to, but you just need to go to the ports and pins part to invert the signal mach is looking for as it's a normally closed circuit vs normally open. If you flip over to the diagnostics page of mach you should then be able to see the probe input trigger as you press on the probe tip.

It is definitely worth spending a couple of minutes dialing in the probe tip using a dial indicator before each use - the runout of the spindle/collets results in me getting anything up to around 0.1mm of runout all the way down at the tip which will affect any probing results. Within a couple of minutes of careful tweaking I can get that down to less than 0.01mm

As for probing on mach3 - I've never done it. I think there were some screen sets for mach3 that have probing built in, or you could write a small macro to do it (or use someone else's) but the info is out there if you have a look. Mach4 makes things quite simple with a dedicated probing section built in so I've never had to figure anything out in that regard.