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« on: July 12, 2008, 09:39:26 AM »
Cutting a circle is a good test of what the machine can do. Play around by milling a circle a number of different ways to see what you get. This is done done after MACH is set up. Having a flavor of what your machine will do saves you from not wasting time on something that may never happen. Use a piece of round stock as this is easier to measure. if you can't achieve some tolerance on the outside you probably won't get it on an inside cut.
Start from the center of the stock and make a single circular light cut. Measure diameter in 90 degree increments noting the plus or minus away from what was wanted.
Now try milling a circle using same cut, multiple cuts or finish cuts, start the actual cut from different quadrants, etc. and see what you get out of them all.
You can mimic rotating the piece, offset the center starting point, change the axis backlash deliberately wrong or the steps wrong, etc..
Long story short, your just trying to set up and compensate for what your machine couldn't do in the first place such that a circle comes witin some tolerance. Please note, that what I am posting, is after MACH is set up, and again are
just machining "tricks" which you can fool around with later on.
RICH