[gort]

Wrote the attached Gcode for my DIY Woodworking CNC.
Remove the ".txt" as cnczone chokes on .nc type files.
SEEMS TO BE A VERY GOOD TEST, helped me track down several
issues with Play/slop, etc. Easy VISUAL inspection.

Drills 2 sets of 25 holes, drills every hole twice, but NOT sequentially.
Drills 5 holes per 5 ROW, then reverses and drills them again in opposite order.
Then drills 5 holes per 5 COLUMN, then reverses and drills them again in opposite order.

RESULT is perfect round holes if CNC is accurate and repeatable, else
get OVALS with direction of oval axis indicating what type of issue is causing error.

Attached Gcode, 3D mach3 screen shot, finished wooden block full of holes.
USER parametrization, so you can change space between holes, and other parameters
easily in the USER section of Gcode using windows notepad.

Hope this is helpful,

Gort

P.S. Thanks TT for pattern suggestion.

[Graphicman]

Great test Gort thank you
i have just ran this test with a 3mm end mill , we can say i got perfect holes when the test is done
the machine i am using is very rigid and it has zero backlash , i am using rexroth and thx linear rails, however i have an average error of 0.17mm in circles and square tests, any ideas what would be causing this issue?