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There is a "Tips & Techniques" in the Australian Woodsmith issue 77 that got me quite worried. It's a DIY dado set designed by some folks at the Goulburn Region Woodworkers club.
They used three el-cheapo saw blades with CDs for spacers. :oo:
I've seen CDs exploding before at high RPMs (20,000+RPM). I guess a saw doesn't spin quite that fast (maybe around 3000RPM?), but surely it's risky business. I'm more surprised that they actually published such a tip claiming it as "clever."
Cheers,
Af.
I have not seen the article and do agree that cd's can shatter. I once had a CD that I was disposing of and something told me to turn it away from me when bending. It broke in splinters. I was picking up bits of CD's for a week that got lodge in the carpet.
Are the CD's clamped tight by the saw blades? If so it probably is a clever idea as they are unlikely to break due to centripetal force...however it could be an issue if they were impacted by a piece of wood somehow??
Hmmm ... even if they are clamped tight they could easily still shatter and spit out through the blades.
The clamping pressure will only be at the centre of the blades and CD anyway.
A 52X CD-ROM drive (about the fastest in common use) spins the disc at around 27,000rpm........a tablesaw blade spins nowhere near that fast, so is probably OK.
One issue with CD-ROMs shattering was people using discs that were only rated for slower drives (remember the old 8X, or 16X CD-ROM?) in faster 40X or 52X drives. It turned out that discs for faster rotation needed to be more precisely made, i.e. hole more accurately centred, to prevent out of balance vibration. Just about all CD-ROM blanks sold these days are manufactured to tolerances suitable for fast 52X drives, so these are unlikely to fail at tablesaw speeds.
Of course, if the discs are damaged or cracked in any way, then all bets are off !! :oo:
Given the liability issues, I'm surprised that anyone still publishes "Tips & Techniques" at all. Anything that uses a component or part in a manner it wasn't designed for is taking a bit of a chance IMHO.