Ball-Drilling
Jig
| JIG HOLE GUIDE | |
| Ball Dia. | Hole Dia. |
| 3/4" | 1/2" |
| 1" | 3/4" |
| 1-1/4", 1-1/2" | 1" |
| 1-3/4", 2" | 1-1/2" |
| 2-1/4", 2-1/2" | 1-3/4" |
| 2-3/4", 3" | 2" |
Drill the counterbored holes for the carriage bolts and the large holes in the base and cap. (See the Jig Hole Guide at right.) Insert the bolts, and center the jig by lowering the bit back into the hole and holding it there while you clamp the jig to your drill-press table. Place the ball over the hole, slide the cap down on the protruding carriage bolts, and tighten it onto the ball with washers and wing nuts. Chuck in the proper bit and drill away.