A Scraped CD

CDR's are great things, but what to do about old backups? You can't just throw them away, lest someone fishes one out of the trash. Breaking them isn't very satisfying, and they jam paper shredders. Sticking one in the microwave oven is good fun, but the fumes are probably toxic and I don't have a microwave. I do have this broken 52x CDROM drive though. I opened the drive up and figured out how the two motor driver chips worked, then grafted a PIC microcontroller (16F84) onto the CDROM drive. A couple control lines from the drive's processor were cut with a knife, but most of them were not- the PIC just overpowers them to turn the motors on and off. Yeah, I know that's bad but screw it. It works good enough.

Disaster struck shortly after I made the device. An AOL CD literally exploded with a giant BANG! The front of the drive was blown off from the pieces that came flying out. Fortunately the plastic shrapnel was kept inside the drive for the most part.

So much for AOL getting installed with this drive.

Another shot of the destruction. Yes, that little PCB is an Intellivision power board. I'm using the 7805 to get 5V for the drive from the 12V on my power supply.

The CD is spinning at 12000 RPM. There is a "synch" pulse on the motor which I stuck the frequency counter on. This gives a very accurate speed readout. Without a CD, the motor spins at about 18000RPM.

This is the scraper that does the damage. It is just a small spring screwed into the sled, after the lens/focusing assembly and laser were removed. The end is sharp and the springiness keeps it against the CD.

Another angle.

Yet another angle!

The results.

The bottom of the CDROM drive. My wiring and little add-on PCB are easily visible.

The PIC is in a socket, and there's a resonator to run it. Whoopie. :-)

Movies of it in Action

NOTE: IE users may have to right-click on these and Save As. I dunno why. Eventually I want these to be MPEGs

Scraping the hell out of the CDR!

Finishing the job.

The back of the drive while in action. The rapid sled movement can be seen.

A Closeup of the disc getting beat on.

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