Boring holes in a piece of sheet metal can present a drill-press operator with a potentially hazardous situation. Sometimes the piece won’t fit in the drill-press vise, and clamps or Vise Grips often slip and can be cumbersome to use. Even worse, inexperienced operators will try to hold the workpiece with their bare hands. If the bit binds, the piece can spin around and gash a hand or arm with its sharp edges.
The drawing shows a hold-down fixture that I use to anchor small pieces of sheet metal during drilling. As shown in the drawing, it’s a 20-in. square piece of 3/4-in. plywood with a U-shaped notch cut out of it to create a couple of legs that fit loosely around the drill-press post. I position the part I want to drill on the plywood and secure it along the edges with four sheet-metal screws. In use, I slide the hold-down around the drill-press table as needed to center the bit on the centerpunched points that need to be drilled. The oversize notch in the plywood makes it easy to move around the drill-press post. At the same time, the legs keep the hold-down from spinning out of control should the bit bind and the operator lose his grip on the hold-down.
Mark Francis, San Diego, CA
