Im wondering if anyone has had a problem with the touch probe software, when i turn the machine on and carry out a zero everything works perfectly, however if i try to zero the z or xyz the continue box is grayed out an i have a black no entry sign on screen (round circle with a line through it), what am i missing?
Ok problem solved, i watched a video that said you could be within 2-3mm of the surface however the onscreen instruction do say ‘touch’ the probe, an yes if i touch it, it turns green, however what i then found was it would locate one side of the block but not the other side, it simply pushed it along an then came up with error, however i have found i need to turn the bit around (its a 2 flute bit) until one of the cutting blades are inline with the block an then it works perfectly (like all things - obvious when you know), o well another day learning 
I chuck up a V carve bit upside down and probe with the full .25 diameter shank.
Interesting idea, but would the machine know the size of the bit, i assumed that you tell it the size so that it has some idea of how far to move when zeroing, hence too far brings up an error message, i guess if your using a v bit for text it wouldn’t matter about the size as it uses the measurement to find the middle of the bit?