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High-Speed destruction : Hard-Disc platter warping
Hard-Disc platters are a conveniently sized source of aluminium discs. Diameter is 95mm, mass typically 23.2 grams
disconly_2.m1v (2.5MB) 1000 frames/sec
The distance between the starting position and the top of the pipe is about 175mm. It takes about 3ms to travel this distance, giving a speed of 58m/sec, or 210km/hour (130miles/hour)
Liftoff...
3ms later, it hits the top
OK. now what happens when we put something in the way, like a lump of wood..
discwrapwood.m1v (1.6MB) 2000 frames/sec
Slight signs of movement..
500 microseconds later, the disc is wrapped around the wood.
This time, the hub from a hard disc is placed in the centre of the disc :
disc_hub.m1v (2.8MB) 1000 frames/sec
Although not actively held down, its high mass compared to the disc makes it act like
it was, and the disc warps round it.
Once things get going, things get interesting. The whole tube raises up in the air, but
I'm not sure if it's a bounce from the downward force of the coil reacting against the
mass of the disc+hub, or the impact of the hub on the top of the tube. The coil platform
does move down noticeably, but the hub hits the top at about the same time you'd expect to
see the bounce, so it's probably a bit of both....
