First cut too deep on all toolpaths using probe

I’ve been working on creating some projects where I engrave a path, drill some holes and cut the outside right offset to cut a shape in 3/4" pine boards.

The process is to do path, holes, then cut out.

When I did the engraving path, it was set to do a 0.02" (0.5mm) line on the vector with a 1.6mm end mill. I used touch probe to set X, Y, Z with 1/4" end mill. Then swapped in 1.6mm end mill and reset Z.

The single pass actually took 0.125" (5mm) instead. Ten times deeper than it was supposed to be.

For the hole drilling, it was set to drill 0.3" or 7.62mm. Using the same 1.6mm end mill without re-zeroing Z, it drilled the holes at 0.4375" (11mm) instead.

After drilling, I swapped back to the 1/4" end mill, and re-zeroed Z with the touch probe. It was set to take 8 passes at about 0.09" each to remove the full 0.75" of material. On the first pass, it took a full 0.25" (~6.5mm)! I stopped the job at that point, as the depth of the cut caused the material to break free of the clamps.

ANY idea what I’m doing wrong???

Are you placing the Probe as for probing a corner:

but then probing only for Z?


I am nearly positive this is my problem! I will go re-try and report results! I had been leaving it hang over the edge in the same X,Y 0,0 location without putting the whole probe on top for Z.

So question: If I probe X,Y,Z with probe hanging over, it gives me accurate Z, but when I do a tool change, I need to put the probe on top and will still get accurate Z? So there is some sort of offset built in to the probe function in the software that differs between X,Y,Z and just Z?


Correct. Alternately, you can probe once, then use a BitSetter.

Thanks Will, this was exactly what I needed to do. Time to put a bitsetter on the Christmas list!