I haven't jumped into 3D printing yet but keep running into inexpensive cool items like this: http://www.ebay.com/itm/Geeetech-3D-Touch-Auto-Bed-Leveling-Sensor-for-Prusa-3D-Printer-/322501978412?hash=item4b169da92c:g:0nMAAOSwGtRXw~nk

Wouldn't one of those things be useful for setting tools on a mill or router with existing Mach3 software? 

Cool gadget indeed, thanks for sharing.

Tweakie.

Ooh, nice,

wonder if that could be adapted to work on a plasma cutter for top-of-material sensing?

Won't work.
The difference is additive versus subtractive machining.
The bit on the CNC would be cutting on an angle whereas the extruder on a printer places layers down so the angle doesn't make enough of a difference to matter.

Won't work.

I am sure it will.

The difference is additive versus subtractive machining.

Not sure that has anything to do with bed leveling or plasma top of material sensing.

I think you may need to explain your answer in a bit more detail.

Tweakie.

Quote

Won't work.

I am sure it will.

Quote

The difference is additive versus subtractive machining.

Not sure that has anything to do with bed leveling or plasma top of material sensing.

I think you may need to explain your answer in a bit more detail.

Tweakie.

Go ahead and try it.

Quote from: Tweakie.CNC on May 05, 2017, 08:05:42 AM

Quote

Won't work.

I am sure it will.

Quote

The difference is additive versus subtractive machining.

Not sure that has anything to do with bed leveling or plasma top of material sensing.

I think you may need to explain your answer in a bit more detail.

Tweakie.

Go ahead and try it.

its a surface probe, i can't see any issue with the type of machining?

The intended purpose of the sensor is not to compensate for an out of level table or z-axis.  It would be used as a simple z-axis probe input to accurately locate the work surface or the tool tip for cheap.  Taking advantage of cheap as chips Chinese 3D printer technology.  

Me being me, I will need help making it play nice with Mach if I decide to try one.  I guess it will require a macro or the like?

It might need some interfacing - the blurb mentions servo input, pwm, solenoid etc, I cant find much out about the internals or the sensing method used but if the repeatability is anywhere near as good as stated it must be worth a try i think.

Also, being for 3d printers which are generally lightly built, i would presume the surface contact pressure is very low which would be good for TOM sensing in a plasma cutter

Of course it will work.  Its just a fancy limit switch.  You can do probing with any device that can provide a switching function upon sensing a surface.
The 3D printing community is quickly moving to non-contact proximity sensors for print bed zeroing, bed leveling, and now XY Axis skew correction (corrects for X and Y axis not perpendicular).

Your choice of sensor (or switch) depends on the accuracy you need.  If you go with non-contact, there are many different types depending on the sensing technology and accuracy needed (i.e. Inductive, capacitive, etc.)

Below are a couple of examples.
http://www.ebay.com/itm/LJ12A3-4-Z-BX-Inductive-Proximity-Sensor-Switch-NPN-DC6-36V-3D-Printer-CNC-/122184058393?hash=item1c72bcc619:g:rG8AAOSwNRdYAyiX