Thinking on....the bits are slowly falling into place possibly....
I need a fixed touch-plate somewhere on the bed (could be movable I guess but...) This would be connected to my probe input.
I know the height of this plate/block etc. lets say 25.00mmm for fun.
I would need a fixed (insulated) probe permanently mounted in a holder, it would have a ball-end of known diameter.
What I keep getting muddled over is where is the correlation from fixed probe to tool height??
Presently, I zero my height setter, place tool or probe, measure and enter the result in the two table - this works 100%
But what would i zero on the mill? Is G53 Z0 the reference?
If yes then I can see it all playing possibly:-
Place probe in spindle, probe until touch plate reached, read current machine DRO for Z and set that in the tool table after subtracting my 25mm offset.
Place tool in spindle, probe until triggered, store Z machine DRO, subtracting offset again.
Then i can probe the work and the lot should work I think??
BUT....
What happens when I break a tool and need a reset - the knee will have moved and now my Z ref is no longer correct
Confusion much