"Get a Ball" Out of Your Woodworking

Step 1: Cut out the stock.  Follow the list of materials at the end of the article. For best results, we suggest you use a hardwood such as cherry or maple. Cut the round discs (A thru E) using your bandsaw or scroll saw and mark the center of each piece clearly.

Step 2: Drill a 1/4-inch hole in the centers of parts A through E.  Mark the part letters on pieces B through E. Now, make
the simple clamping jig shown in Figure 1 from a 3/4-inch x 8-inch piece of stock and a 1/4-inch-20 x 3-inch pivot bolt. 
 
Next, stack discs B, C and D over the pivot bolt on the jig with disc B on the bottom. Lay the jig flat on the surface of your MARK V Drill Press Table, with the stacked discs clamped in position with 1/4-inch-20 nut and washer so they won’t rotate.
 
Locate a point 3/4-inch in from the center of your discs and drill a 5/8-inch diameter hole. Set your drill press stop to drill all the way through discs D and C . . . but only half-way through disc B.  Drill your 5/8-inch hole. 
 

Step 3: Rout the slide lever slot on disc C by first marking off the 2-3/4-inch arc on the edge of the disc. Tilt your MARK V’s table 90-degrees so its surface is parallel with the machine’s way tubes, then clamp the jig to the table surface as shown in Figure 1 . . . so the point of your drill bit is in exact left-right alignment with the centerline of your pivot bolt.
 
Mount disc C over the pivot bolt and drill a 1/4-inch diameter by 1-inch deep hole at each end of your drawn arc. Next, use your MARK V’s Router Attachment with a 1/4-inch Bit to rout a 1-inch deep groove, connecting the two 1/4-inch holes you just drilled.  Caution: Do this in shallow, 1/8-inch deep passes to ensure the smoothest slot.

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