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With the miter gauge in the left miter slot, rest the sacrificial fence’s edge on the table surface, positioned where you want it side to side.
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Miter gauge: It has a single T-slot washer and three spring-loaded ball bearings in the side of the bar to maintain a perfect fit in the miter slots.
Miter Bars & Kits
Alignment, and cutting miter slots in the homemade table sawhttp://woodgears.ca/homemade_tablesaw/alignment.html.