Again, thanks for the suggestions and reference links.
Gleaning what I think was the best approaches from both sources (based on my skill level), I decided to create a ‘calibration board’ just 2" smaller in both directions than my machine’s usable work bed to determine if there was any x or y “run-out” across the entire table.
However, CC threw me a curve ball when it wouldn’t let me use a 1/4" end mill to cut a 1/4" wide x 28" long pocket (re: “empty tool path”)
I then measured the 1/4" end mill’s diameter and found it was actually .2480 and not the .2500 listed in the tool DB. I also measured over 6 different 1/4" end mills from several vendors and found this to be the norm across all vendors.
So, I changed the tool’s diameter in the DB to reflect the tool’s actual .2480 diameter.
CC then allowed me to use that same 1/4" end mill to cut a grid consisting of 3 parallel 1/4" wide horizontal (“x”) and three parallel 1/4" wide vertical (“y”) pockets evenly spaced across the entire board.
Result: All grid lines were perfectly true (measured to 1/128th of an inch) to their respective x or y base line reference points located on the machine’s frame, as well as parallel to each other on the board across the entire bed showing me the machine’s x and y gantrys (?) are both square to one another and to the table’s usable area and that the belts are equally “tensioned”.
Next, wanting to know how thick a pocket vector’s lines are in CC, I changed the tool’s diameter in the DB to .2499 and CC still accepted it (re: CC didn’t indicate the pocket was an empty too-path)
So it can be concluded that the usable space between pocket vector lines is reduced by .0001" (I’d say .00005/vector line, but I don’t believe the machine’s tolerance is that tight)
Lastly, creating a 1/4" diameter pocket using the 1/4" end mill listed with a .2480 diameter in the tool DB resulted in a 1/4" diameter round pocket…as expected.
Conclusion: I’m happy now that I have a better understanding regarding tool and machine tolerances and how those tolerances need to be factored together into designs when a higher level of precision is needed. Yeah, yeah, yeah…I realize this isn’t a commercial machine, but at least now my expectations are correctly aligned with what the machine can produce.
Again, thanks for everybody’s input. It helped make me think this through on several different levels that I would never have considered exploring on my own which helped me design a calibration verification test that I could understand and more importantly, conduct.
