Glad I could help with the angle calculation. Here is something to consider. If you are not currently using the A axis you can make use of it. The A axis is rotation about the linear X axis and uses DRO 803. You can set the A axis to be active, write a value into the A axis DRO and then when you leave the script it will be there for you to see on screen.
There is also the option to do the angle calculation in Gcode using G31. When you probe using G31 the values of X Y and Z at the probing point are written to parameters #2000, #2001, #2002.
For example set up parameters
#50 = 0 (X axis change, you could set this to 20)
#51 = 0 (Y axis change, may not be needed)
#52 = 0 (Z axis change, you could set this to 3)
#53 = 0 (slope, may not be needed)
#54 = 0 (angle)
#1000 = 0 (temporary variable)
#1001 = 0 (temporary variable, may not be needed)
#1002 = 0 (temporary variable)
So go to your first probing point, set your own temporary variables to the values at the probing point.
#1000=#2000
#1001=#2001 (may not be needed)
#1002=#2002
Go to your second probing point then the axis changes will be given by:
#50 = #2000 - #1000
#51 = #2001 - #1001 (may not be needed)
#52 = #2002 - #1002
You may need to change the order of the variables in the subtraction if the angle comes out as negative when you want it to be positive.
You can then calculate the angle of the probed face using Atan in Gcode
#54 = Atan[#52]/[#50]
Once again I have not checked this out on my machine.
If I was setting this up I would probe using Z axis movement, not X axis movement. For a shallow slope a small variation in Z axis positioning will give a large variation in the X axis result, in this case at a ratio of 20:3. So if you move the Z axis and it is 0.01mm out of position then the X axis probe error will be in the ratio of 20:3, 0.0667mm. If you move the X axis and have an error in position of 0.01mm then probe in the Z axis then the error will be smaller in the ratio of 3:20 so 0.0015mm
If doing this in Gcode and not using the A axis you can also use G0 A #54 to set the A axis DRO to the calculated angle (make sure you are in G90 absolute mode for this or you will get odd results).
