Talk:CD shattering

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[edit] From Reference Desk

MythBusters explored this a while ago and found that normal CDs will not shatter in a conventional CD drive (the spin speed isn't high enough). However, the stresses on a spinning CD are considerable, and a defective CD (a small crack, a weak spot, manufacturing error...) could shatter under normal operation. — QuantumEleven 19:55, 16 September 2006 (UTC)

It only takes a very small amount of flutter in a 40x CD-ROM drive to create a whole lot of friction, and it's pretty easy for that to happen if your CDs are poorly balanced (you can actually slightly unbalance CDs by writing with some types of ink on only one side of the CD) or if the CD-ROM motor is starting to get old. Once the fluttering starts (you can usually hear it, though CD-ROM drives often flutter with no concequence) a CD can explode with even the slightest bump, or like Quantum said, a small crack or weak spot. These things used to be very common back when people were trying to manufacture rediculously fast CD-ROM drives, though it seems that everybody has settled for about 40x nowadays.  freshofftheufoΓΛĿЌ  07:35, 17 September 2006 (UTC)

With all due respect to MythBusters, cd's can shatter. It happened to me yesterday, hence my searching the internet for other occurrences. And it was a commercially recorded cd game, not a no-label mystery cd. The cd shattered, blowing off the door of the CD and spraying the room with fragments.

A nearly new CD in my Samsung CD-RW/DVD Drive SM-348 exploded loudly about a week ago. The drive retained the fragments, but is no longer usable, even after careful cleaning. Apparently CD explosions are not rarities. Wugo 02:49, 8 November 2007 (UTC)

[edit] Typo fixed (kph was wrong)

From the article: "The velocity of the edge of a 120 mm disc rotating at 10,350 RPM is approximately 65 m/s. (243 km/h, 145 mph)"

The speed at the outer edge of the CD would be v = r*Omega = r*2Pi*f (Frequency) = r*2Pi*n/60 = 0,06*2*Pi*10350/60 = 65,03 m/s = 234,1 km/h rather than 243 km/h.

Centripetal force: a = (v*v)/r = 65,03*65,03/0,06 = 70481,7 m/(s*s) = 7184,7 g

Also interesting to note is that a dot of ink with weight 0.01g on the edge of the CD will exert a force of 0,705 N (as 72 gram would) on the spindle!! Thanks dad, for alerting me to this! ;-)

FIXED ;-)

Ft. Jack Hackett 23:24, 5 May 2007 (UTC)

[edit] Is it possible to make drives spin slower?

I certainly don't want my 20-year-old music CDs ruined by some stupid 48x drive that spins too fast. I'd buy a 10x drive if I could find one, since I am in no hurry, but those don't seem to be available. ---- Theaveng (talk) 19:24, 9 January 2008 (UTC)

Well, there are utilities that can set a lower maximum speed, primarily intended for reading scratched discs and degraded burned media. I do believe Nero includes one, and it indeed may even be part of their free DriveSpeed utility. Go take a look at that. Also, I do believe that a computer will run its CD-ROM spindle at 1X when reproducing redbook audio CDs. Even if not, in truth, the risk of a shattered CD is truly very minor. --24.91.98.99 (talk) 02:33, 29 May 2008 (UTC)