i use sliding mitersaws everyday.....put away your protractor and measure what you`ve cut.
when tuning up a chopsaw i like to use mdf that`s the full width of the saws crosscut capability......
first true to 90º by cutting a board then put the other edge against the fence and cut a sliver about 1/4" off the end.......using calipers measure each end of your cut......a saw set at 90º will be the same......any error is magnified x2......adjust the fence to correct any error.
i`ve never seen a name brand saw (even the cheap ones) that if 90º was on the miter settings where off.......all of the bases are cnc cut with tapered slots so unless somebody has drug the stylus over the detents they should remain true.
after you set the saw up then it`s all how you hold your tongue
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