I've worked around this issue but I've never completely understood it so I'm hoping someone can provide a lucid, explanation.
For example, if I have the following G code:
M6 T6 (selects a tool)
G0 G90 X0.75 Y-2.75 E1 (positions my table/fixture precisely under the tool)
S3500 M3 (spindle speed @ 3500 RPM CW)
H6 Z0.3 M8 (selects tool length offset, sets I-plane [tool position] 0.3 above part, turns on coolant)
I'm working on a flat surface, no steps, no clamps to clear.
Now, I use G82 for my spot drill because I like the option of the dwell before retract. So if I program as follows:
G82 G98 R0+0 Z0.03 F12. P100 X0.75 Y-0.5 E1
Why can't I set R0 at zero? The Fadal manual states "The I-plane must always be equal to or above the R-plane" and "In the absolute mode the value for this location is relative to Z zero". The explanation and drawing in the Fadal manual clearly suggests that R zero (R0+0) would be at the surface of the part which is 0.3 below the I-plane.
Maybe I'm having a bad day but darn this R-plane concept baffles me.
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