cd-romtuningdials

CD-ROM Tuning Dials

A Use For Outdated CD-ROM Disks

For some time I have thought that outdated CD-ROM disks should make rather good tuning dials, but lack of a suitable hub kept me from trying them. Recently I acquired a metal turning lathe which allowed me to make hubs for these disks. You could also turn these using a drill press, or a wood turning lathe.

The first hub was turned from aluminium and has four 4-40 screw holes for fastening the disk to the hub. Due to the width of the screw head, it is impossible to place these screws close to the 1/4 inch shaft hole. As a result the screw threads put some pressure on the plastic CD-ROM disk as the screws are tightened. This caused the disk to crack in several places.

The second CD-ROM hub was turned from fiberglass. The hub is fastened to the disk with super glue. This worked much better. The bond is good and no cracks developed in the disk.

Both hubs were drilled 1/8 inch and tapped for a 6-32 set screw. The fiberglass hub seems to hold the set screw with no problem when tightened onto a shaft.

A section of clear plastic can be mounted above the CD-ROM disk with two stand-off bushings and screws. Scribe this index sheet down the center and fill the scribe mark with black ink.

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Two CD-ROMs, one with a bolted on aluminium hub, and one with a glued on fiberglass hub. Both have been given a coat of grey primer and a coat of white paint.

The CD-ROM with the glued on fiberglass hub.

The CD-ROM disk with an aluminium hub. This photo shows the cracks that developed as the four 4-40 bolts were tightened.

Almost done. The index strip needs to be built and some dial markings applied.

Here is the result. A wedge of clear plastic was cut, marked down the center with a black line, and mounted above the CD-ROM dial on two stand-off bushings.