Dado

Jim Morgans Wood Profits

Wood Profits by Jim Morgan

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Fig. B Layout of the Abrasive Disks

Each abrasive disk has two dadoes cut in it. The angled dado allows you to slip this disk onto the driver. When you twist the abrasive disk, the driver engages the straight dado and is locked in place.

Dado Layout

American Woodworker JANUARY 2003

Cut dadoes in a set of square blanks to begin making the twist-and-lock mechanism of the abrasive disks. Caution: You must remove the guard on your saw for this cut. Push down on the blank with a hold-down block to keep your fingers out of harm's way.

Glue short stop blocks into both ends of the dadoes. Make sure the end of each block is flush with the side of the blank. Put pressure directly on each stop block with a small clamping block.

Drill a hole with a Forstner bit in the center of the abrasive disk and driver blanks. Then saw the blank into a rough circle. (The center hole will help you sand the disk perfectly round.)

Drill a hole with a Forstner bit in the center of the abrasive disk and driver blanks. Then saw the blank into a rough circle. (The center hole will help you sand the disk perfectly round.)

Cut dadoes in a set of square blanks to begin making the twist-and-lock mechanism of the abrasive disks. Caution: You must remove the guard on your saw for this cut. Push down on the blank with a hold-down block to keep your fingers out of harm's way.

dado cuts on the abrasive disk blanks (Fig. C, below). Simply drill it out with the 1/2-in. Forstner bit.

8. Lay out holes for rare earth magnet cups and washers on one of the test pieces (Figs. B and C). Then set up the drill press fence and stop block to drill these holes in both the driver disk and sanding disks. Be particular about the depth of all of these holes. The washers and magnets should be either flush with the surface of the disk or slightly below it.

Round the Disks Without a Lathe

1. Cut all the blanks into approximately round shapes. Then make a simple sanding jig for the disks to rotate on (Fig. D, page 71). Put a coarse sanding drum in your drill press and mount each disk on the jig (Photo 7, page 71). Secure the jig to the drill press table with a single clamp. By hand, rotate the roughly circular disk against the sanding drum, hitting only the high spots.

After each rotation, tap the corner of the jig with a mallet to nudge the disk slightly closer to the drum. It won't take long before the disk is perfectly round. Small differences in diameter between the disks won't matter.

2. Epoxy the shaft (A4) into the driver disk (Photo 8). (First, be sure to check that your table is absolutely square to the shaft, both front to back and side to side.)

3. Epoxy two pieces of square key stock into the dado on the bottom of the driver disk (Fig. C, below). If you can't find two pieces the right length, buy three and cut one shorter with a hacksaw.

4. Fasten washers and cups for the rare earth magnets to the disks (Photo 9).

5. Flatten the bottoms of all the sanding disks on a medium-grit lapping plate. Spray the bottoms of all the sanding disks with three or four coats of lacquer, and sand out the bumps.

Fig. C Layout of the Driver Disk

The driver disk has one dado to receive glued-in pieces of metal key stock. The key stock engages the dadoes cut in the abrasive disks, so the two disks turn as a unit.

3/8" SQUARE KEY STOCK

"-DEEP HOLE FOR SHAFT

Bottom of Driver Disk Top of Driver Disk

American Woodworker JANUARY2003 69

CLAMPING : BLOCK

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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