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Investigating Angular Velocity
mbreitba writes "Sam Barros is at it again, Some may know him for his Railgun research, and some may know him for his homemade cannons. But now he's found a use for all those old CD's you don't need anymore. Personally, I couldn't think of a better use for them."
52x isn't the max its 172x!
I don't care if the cd could come out of my burner fly across the room and explode into a billion pieces, I wanna 172x burner!
seriously though, why do they only try to spin the cd faster. why not spin the laser in the opposite direction the cd is spinning in?
bite my glorious golden ass.
Copyright © 2002 by Sam Barros. All rights reserved. Removing any material from this site for display without consent from its author consists in an infringement of international copyright laws and can result in fines up to $50000 per infringement, plus legal costs. So ASK ME before you remove anything from here.
Oops, if anybody visited the site and it was all blank, sorry, that was me after I removed his content! I'll put it right back.
I love reading all the different ways people threaten in their copyright notices.
But wasn't a better version of this concept posted here like last year? A guy put the CD in a real high-speed, high-torque moter (not a dremel) and watched it shatter on the spindle.
This guy is just spinning them fast on a dremel tool and watching them shatter when they hit the ceiling, not quite as impressive!
turns out most cds explode at 28k rpm according to this story from a couple years back. and even then it was a dupe.
... or put 'em in the microwave for a couple of seconds, shiny side up. Put a sheet of paper below if you don't want to stain the glass plate.
Trollem mirabilem hanc subnotationis exigiutas non caperet
I have a full copy of that page, with the videos, but no way am I mirroring when the author of the page threatens to sue for $50000 at the bottom.
I bet in the future, you'll be able to get "legacy" CD-ROM drives that just take an optical image of the whole disk once, load the content into a buffer, then eject the disk, in about 5 seconds.
That would be cooler than 12,983x drives.
Whoopie, another story for Power Labs. What's their slogan again ? "We know just enough science to wreck something, then we call it an experiment."
In Soviet America the banks rob you!
Dang! Where are all those AOL CDs when I actually WANT them?
From the site:
A standard compact disk has a diameter of 12cm. If this disk is to spin at 35000RPM, the peripheral velocity at the edges of the disk (.377m circumference x 583.3 turns per second) will near 220m/s, or 722fps, or 792km/h or 492miles per hour. That is one fast CD-Rom!
At those speeds the CD is storing over 150joules of energy.
I wonder if Freezing the CD would make for even more spectacular explosions... after all the speed and energy stored in the CD is really ridiculous.
Freezing usually makes most things more fragile, right?
.: Max Romantschuk
'nuff said.
-Shane
I love teh int4rw3b!!!!!111one1
This is a dupe of thiswhich was a dupe, funny that. Here is a mirror of it (the first dupe), since the site was taken down: My Mirror
Your hair look like poop, Bob! - Wanker.
Guess I should call Big Broth^H^H^H^H^H^H^H^H^H Ashcroft at T.I.P.S. to let them know that AOL has apparently been engaging in some very suspect "terrorist-like" activity, filling my mailbox with potentially dangerous explosives for years.
He also notes the disk speed is lowered due to aerodynamic drag.
Personally, I would have been impressed if he had done something to the disk, maybe going over quarters of it with a black felt pen so an optical pickup could have determined its RPM, instead of guessing.
At those speeds, gyroscopic effects can really be exaggerated! Gyroscopic effects alone can result in some really bizarre behaviour when the plane of rotation is changed.
This experiment reminds me the time we got a flywheel spinning off the table-saw motor in high school shop. The flywheel got away from us when unexpected gyro forces wrenched it from our hands. The damage that thing did was talked about from then on to beyond the day I graduated.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
You'll shoot your eye out!
No boom today. Boom tomorrow. There's always a boom tomorrow. - Cmdr. Susan Ivanova
A few years ago, myself and a friend found another, equally interesting use for old CDs:
You can use a stack of them hooked up together as a big high-voltage capacitor!
We connected them all up, then passed in ~20K volts, and it really could hold it's charge (I can't remember the numbers - since then, I've lived in amsterdam for 3 years, and a'dam tends to have a negative effect on ones memory....). What was amazing was when you hooked it up to the powersource, all the disks were attracted to each other and clamped up really tight.
Discharging the thing was amazing, and the 'zap' (for want of a better word) could easily burn through some thick paper...
Maybe when I've got some time I'll repeat the setup, this time with some photos, then I'll enjoy a good ol' fashioned slashdotting...
tom-george.comBecause geeks rate higher t
Have you ever loaded a faulty CD into a high speed (30X or higher) CD-ROM player, heard it spin up to incredible speeds, rattling and whining, and thought to yourself: "this thing is going to explode"? When CDs came out they were heralded as the solution for the need for high storage-high speed information devices, transferring data at a whopping 150kb/s, but like all technologies, 1x CD players quickly became obsolete as the need for higher and higher transfer rates pushed for faster players, and, with them, higher rotational speeds. As we advance into the 21st century CD players are reaching the ultimate speed limit: we are getting to the point where the CD player simply can not spin the CD any faster or else the CD will literally fly apart. On the interests of the advancement of high speed computing PowerLabs brings to you:
THE ULTIMATE CD SPEED LIMIT!
WARNING: This page is written for amusement only: These experiments are VERY hazardous!; A high speed rotating CD Rom is a bomb ready to explode and will send razor sharp plastic shrapnel in all directions when least expected. DO not attempt to replicate any of the experiments described below!
Setup:
Before an experiment could be devised where a CD would be rotated to complete failure, a proper motor had to be obtained that would be capable of achieving those high rotational velocities with the load presented by a CD. Although a CD is very light and aerodynamic, when it starts to spin at a couple tens of thousandths of rotations per minute the drag created by air around its surface can be to slow the motor down considerably. High torque motors are very common and cheap, as are small high speed motors. Unfortunately however, high speed, high torque motors are a much rarer and expensive find.
My choice was to use a Dremel tool as the motor. It was cheap, easily available, and, more importantly, the rated 35000RPM spindle speed meant that it had some real potential for spinning things to destruction.
At 35000RPM very small imperfections and balancing errors can lead to extreme vibration; so much, in fact, that it would be possible to damage the bearings or bend the axle on the tool if something as heavy as a CD was to start wobbling (bear in mind that the Dremel tool was designed for very small, light weight loads and even then many of its attachments carry warnings not to be used at full speed). One of the first challenges of the research was to find a means to secure the CD perfectly in the middle of the tool. A custom made CNC lathe spun aluminum holder was considered but before I ever left the room I realized that the cylindrical sanding attachments Dremel makes not only fit a CD hole perfectly, but also have adjustable width so that the CD could be gripped in place. With the CD in place and the dremel plugged in, it was time for the fun to begin!
The Dremel was switched on and the rotational velocity was gradually increased to its maximum, at which point the CD hummed and whined in a very menacing manner. Mildly disappointed that it had not exploded, I realized that it wanted out; a quick jerk at the tool and the CD slid out of the holder and contacted the carpet whilst spinning at ungodly speeds. It peeled out a bit in front of me and proceeded to make its way to the door at a very high speed. On contacting the closed door, the CD did a most unexpected thing: it first bounced back a few inches, and then, when it hit the door again, it jumped straight up the door and struck the ceiling, exploding into thousands of fragments which rained down on the entire room. This first experiment was unfortunately not videoed, but it served to get everyone in the room to put glasses on and cower away behind pieces of furniture, whilst people in the hall corridor quickly made their way to my door to ask what was going on. Now, with an audience, the camera was taken out and the real experimentation began...
ÂA standard compact disk has a diameter of 12cm. If this disk is to spin at 35000RPM, th
Last time this happened his site was slashdotted and consquently due to bandwith caps wasnt up till 3 weeks later. Wait till he finds that he has been put on the front page again. Better start looking behind our back's for some guy with a dremel and a couple of AOL cd's.
I'm a geek deal wit it
This picture is great. The guy is sitting on the floor looking at a 35000 RPM CD which is most certainly going to explode, and wearing nothing but a pair of (what looks to be) sunglasses! He looks like a little kid whose found his first book of matches and is mesmerized by fire! I can't view the video (./'d) so I can't comment of his actual procedure, but from the looks of things he could have been in for a world of hurt. At 35000 RPM, that plastic might as well be concrete, or glass.
I keep having these dreams about things exploding. Tonight it was my microwave. I filled it with AOL CD's, set it to 'Aggressive Defrost', and sat down with a beer. The explosion took off the roof of my house and sent it into space. This dream gave me another great idea I can't wait to try: sending cargo into space by blowing up AOL CDs.
Wednesday, 7pm.
It did not work. The neighbour wants back his microwave, and my son is asking me where his music collection went to. Well, that's one positive angle, anyhow.
Thursday, 5am.
That dream again. My subconscious is trying to tell me something. Maybe I was using the wrong brand of microwave...
Friday, 8pm.
I think I've cracked it. Instead of just one microwave, you have to imagine a Beowulf cluster of the things...
Sig for sale or rent. One previous user. Inquire within.
Look at the counter on the guy's page : it has only 4 digits. How much do you bet it already rolled over a hundred times ?
..."
I can just picture the guy in trance mumbling "no, no, I'm not slashdotted, my server isn't smoking, it can't be, I only have 4000 hits so far
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Hang one from the ceiling with a string near a window. It will reflect the sun in to a fairly bright spot somewhere on the floor or wall, give it a little spin. Your cat will chase it as if it's some kind of small rodent but of course never be able to catch it. This may work with exceptionally stupid dogs too. Laser pointers work just as well but require more user interaction.
0000000 0000 ba01 0021 0001 8001 5d16 0000 bb01
...more of the same
0000020 0c00 1680 055d ffe1 e0e0 c02e 20c0 0000
0000040 be01 dc07 ff0f ffff ffff ffff ffff ffff
0000060 ffff ffff ffff ffff ffff ffff ffff ffff
*
0004000 0000 ba01 0021 0a01 8031 5d16 0000 e001
0004020 f307 2e60 0031 9601 1107 0100 917e 0000
0004040 b301 0014 c4f0 ffff b8e0 0000 b801 0880
0004060 4000 0000 0001 0f00 f8ff 0000 0101 f96b
0004100 19ee 4cc7 5b59 835a f211 55fe 3761 f1f4
0004120 5c46 bd6b 9624 0f52 6aed 4c33 6ecd d3fa
0004140 4ad5 78f5 93b2 72db 5375 c5c0 e386 3f6b
0004160 9225 8e50 ef2c 8677 86f9 7fa4 71b5 2357
0004200 9c55 19ac 9fb3 5ddc 1878 cc1c dc3a 8f37
0004220 0df2 bb48 8d4e b6cc 114a efd9 03a0 ca1d
0004240 4ae8 1003 ef91 59bf d78e 0911 d2e4 9190
0004260 608b 6caf 2903 721f 4b90 232f 9d6f 5277
0004300 1143 a8c7 ce5d 8c80 f4da 9824 db82 3ff4
0004320 15b1 56d2 7f64 eb83 bc9c d007 84aa f912
0004340 38c3 b97e f6d1 4fdb edef 2fb9 faac 90d0
0004360 ae25 4b5f 8f14 bff1 e970 f751 dfb9 ad0e
0004400 fbb8 b2ed e179 ea84 56d2 5004 155c 8d78
Will not function likely with a standard scanner since the wavelength do not match, just have explained that.
h ol d=0&commentsort=3&tid=137&mode=thread&pid=6168826# 6169070
http://slashdot.org/comments.pl?sid=67125&thres
--
Karma 50, and all I got was this lousy T-Shirt.
You sir, are an expert troll.
Hmmmmm..... after a minute of thinking. Lasers, among many things can be aimed at very very high speed (ever been to one of those laser light shows?) How about a lens or mirror that spins and a laser that merely utilizes that mirror or lens by aiming at it?
Please people, if youre gonna troll or just make asinine, narrow-minded comments, at least log in so we can list you as "foe".
I did it more than one year ago with a friend of mine, we actually managed to put the disc on the floor spinning at 15K RPM and making it run across the office at high speed for 50+ meters.
:)
:))
We used a pencil to push the disc away from the dremel, if we had to force it for more than a fraction of seconds, the pencil would smoke
At the highest speed the disc exploded (well... it was already damaged, we almost knew it would) and some SMALL piece is still stuck in the roof...
Don't do this at home!
(do it at the office
You will also get a lot of really smelly fumes from the ignition.
I have no idea of the toxicity of these fumes, but I can tell you your pizza will taste funny the next time you use the microwave oven to prepare it.
So, if you wanna experiment, do it in someone else's oven.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
Now I know what to do with that new metallica cd. *shudders* damn that saint anger
If I reemed out the hole that wide, there would be no CD left
(And I like how the "DO" is capitalized instead of the "not")
Maybe he was imagining R. Lee Ermey saying it...
DO not attempt to replicate any of the experiments below, maggot! YOU WILL not live another day if you do, do you understand me? I CAN'T HEAR YOU!
http://xkcd.com/386/
Unable to resist...
Ye olde "9 pregnant women having a baby in 1 month" argument... For another analogue that may apply here, it's worth noting that recent developments in semiconductor processing technology includes a move to 30cm wafers, specifically to accommodate parallelism in production.
I don't remember the dates specifically, but silicon production "began" with 3-inch wafers, then transitioned to 5-inch, then 8-inch. So, don't be too harsh on those who suggest doing things in parallel.
Producing 1000 CDs per day? Consider standard pressing techniques, which is nearly as flexible as "burning" CDs but way cheaper and can be performed as quickly as you wish. (Did you know that CD sputtering chambers can contain multiple different blanks?)
Had one come out and chase me around the lab a bit. An HP VL 400 low profile desktop with a quirk in the CD drive that if you pushed the eject button more than once, it stored the button actions. Pushing it twice quickly resulted in it opening about one centimeter and then closing again. Pushing it three times while the disk was spining full speed caused the tray to open without waiting for spin-down! The disk got air born (only for about half a meter) and skittered across the table after me as I back peddaled away from it in surprise.
The first time it surprised me, the next ten times, I did it on purpose! (Screwed that NT 4 WS disk up pretty well, IIRC).
Any technology distinguishable from magic is insufficiently advanced. - Geek's corollary to Clarke's law
That's something else entirely, which you would've known if you compared the URLs.
Do the 1045-Hours-Free CDs do more damage than the older 720-Hours-Free CDs?
...
....because, you know, it might be time for an upgrade.
"Lawyers are for sucks."
- Doug McKenzie
The secret to carving CDs is to go slow and insure the rigidity of the CD.I find that by using contact cement and gluing a piece of 1/8" plywood to the BOTTOM of the CD, I can use a band saw on a CD quite well. The wood prevents the CD from bending, which will cause it to catch and crack/shatter or chip. I've also found grinding wheels to work well, too ... but the same thing, you need to attach something rigid to prevent the CD from bending. I find plexiglass to work well, too.
-Ab
Nothing fails quite like prayer.
It's not circumference times the rotational velocity. It's the RADIUS times the rotational velocity.
.06 m x 583.3 rotations / second (using his numbers) = 34.998 m/s = 114.8 fps = 78.3 mph.
So, for the standard CD thats:
If it really was going 220 m/s, that's a significant fraction of the speed of sound at sea level (340 m/s).