Investigating Angular Velocity 271
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."
they've been lying to us (Score:5, Funny)
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?
Re:they've been lying to us (Score:4, Interesting)
Re:they've been lying to us (Score:5, Informative)
Re:they've been lying to us (Score:5, Insightful)
Too expensive, and for what? Is a CD burned in 3 minutes not fast enough for you? Would you be willing to pay 4x as much to burn a CD in only 1.5 minutes?
Re:they've been lying to us (Score:3, Insightful)
hell no its not fast enough.. if I wanted to make a backup of my cd collection at 3 minutes a disc it would take me a week! I dont know about paying 4x as much for 1.4 minutes but let the market decide that one.. don't decide 3 minutes should be fast enough for everybody. If there was a burner that could burn a cd in 5 seconds I'm sure there are plenty of people willing to pay a premium for it
Re:they've been lying to us (Score:3, Interesting)
Re:they've been lying to us (Score:2, Interesting)
seriously, sometimes you can split the task into parallel tasks and use multiple units to scale horizontally but in the end it still takes 3 minutes to burn a cd! 3 minutes is a long time when your in a hurry. also, if it takes a scsi tower with 32 burners at 48x to burn
Re:they've been lying to us (Score:3, Informative)
Arguing for the sake of arguing... (Score:5, Informative)
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?)
Re:they've been lying to us (Score:2, Interesting)
I have a
I want to make more than one copy of a cd.. maybe I want to make 100 copies?
I want to just fill a cd with some files off my computer and I dont feel like waiting.
Have you ever tried copying 650 MB worth of data from one hard drive to another? This itself will probably take a few minutes.
we're not all using eide fu
Re:they've been lying to us (Score:2)
Re:they've been lying to us (Score:2)
Actually, now we have something to do with all the frisbies and AOL cd's/cup coasters we've been saving over the years, dont we.
I'll bring over my dremel this weekend.
Re:they've been lying to us (Score:2)
Besides, 4x as much is pretty much the diffrence between a $50 CD-r and a $200 CD-r... what I get for the ide units on www.pricewatch.com and based on shopping at office depot.
If you honestly could build a CD drive that employed the use... to make things simple here.. a stationary disk and a spinning laser rea
Re:they've been lying to us (Score:2)
Re:they've been lying to us (Score:2)
Re:they've been lying to us (Score:2, Funny)
I think you would do it sort of like the prime number shitting bear. [surfeu.fi]
Re:More lasers! (Score:2)
Re:they've been lying to us (Score:3, Funny)
You mean something like this [trygve.com]?
Kenwoods w/ ZEN Technology (Score:2)
You can find a little info on them here [pcstats.com].
I have a 52X that still works well. Quietest freakin' drive I've ever used.
Re:they've been lying to us (Score:2)
Re:they've been lying to us (Score:2)
That's an amazing idea. Do you know any names of companies that are working on that? Or where more information could be found?
Re:they've been lying to us (Score:2)
Come to think of it, its possible to have a tiny moveable mirror reflect the laser around in circles on the CD. A parabola-like reflector beneath the CD can direct the laser and the read data with only the little mirror being moveable and the CD being stationary. I think it will fit in one drive bay, and can be completely financially feasable.
Re:they've been lying to us (Score:3, Interesting)
Re:they've been lying to us (Score:3, Interesting)
P
Re:they've been lying to us (Score:2, Insightful)
if you design a network of spinning mirrors, there shouldn't be a problem, because the light can still travel back through the set of mirrors back to the sensor which is located next to the laser
Re:they've been lying to us (Score:5, Informative)
Um, no (Score:2)
b) The latest IDE standard can push 133 MB/sec. Even taking into account overhead, an ATA100 7200 RPM hard drive can easily do 40 MB/sec in the real world. (That's what my drive does.)
Since 1x CD is 150 KB/sec, 48x is only 5-6 MB/sec, a small fraction of what even ATA33 is capable of, let alone ATA133.
Re:they've been lying to us (Score:5, Funny)
Re:they've been lying to us (Score:5, Funny)
Not possible to move laser? (Score:2, Interesting)
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".
Re:Zero RPM (Score:3, Informative)
http://slashdot.org/comments.pl?sid=67125&thres
yawn (Score:5, Funny)
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!
Re:yawn (Score:2)
I decided not to build that centrifuge. Hmm, chunks of steel at 1800 km/hr... It was just a little too scary for me.
Re:yawn (Score:2)
Already been investigated.. (Score:5, Informative)
Either do that... (Score:5, Informative)
This stinks...(a bit offtopic but reply to parent) (Score:5, Informative)
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.
mirror (Score:4, Interesting)
Re:mirror (Score:2, Funny)
Re:mirror (Score:2, Informative)
But according to this (another slashdot comment), you have violated his notice (removing any material), if you were planning on displaying it (doesn't say anything about public showing), so I GUESS YOU'RE SCREWED (or not):
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 l
fair use display. (Score:2)
I'd also like to share a sad story of a lab death due to flying glass. Somewhere around 1989, a student at Tulane died when a piece of glassware exploded in his hand and a fragment severed his jugular ve
why spin the CD at all (Score:5, Interesting)
That would be cooler than 12,983x drives.
Re:why spin the CD at all (Score:2, Interesting)
This would have been quite a while ago. Anybody else remember these?
Re:why spin the CD at all (Score:2, Interesting)
This would have been quite a while ago. Anybody else remember these?
Yes. I used to work in a small computer store. These 'wonders' were also sold w/o their own hard drive, as 100x cd-readers.
What they did is spend about 10 minutes staging when you put a new cd in, making an image of it on the hard drive, but telling your PC th
Re:why spin the CD at all (Score:2)
Sadly, yes. I used to be a developer for one of the companies that did those...
Seems like they even made it into production:
http://www.axis.com/products/cd_dvd/
Not that we were the only company that made those...
Re:why spin the CD at all (Score:3, Interesting)
This article from CNN makes mention of such a thing coming from Sony.
sounds incredibly cool! but it's part of Sony's megathousand dollar line of products in development. Im not sure what it is or how it works, or even if its close to the idea. This is the only place ive ever seen mention of this thing.
sounds pretty cool though!
ta (Score:2)
Actual site http://www.cs.huji.ac.il/~springer/ [huji.ac.il]
Re:why spin the CD at all (Score:5, Informative)
Re:why spin the CD at all (Score:2)
So how do multi-layer CD's (DVD's) work? Different frequencies of light?
Re:why spin the CD at all (Score:2, Informative)
The explanation with scattering pits, and focus are for the masses who do not know what destructive interefence is
Whooopie (Score:4, Funny)
Re:Whooopie (Score:4, Funny)
If that's the case, we're doing a damn impressive experiment on their web server. Yee-haw!
Cheers,
IT
AOL (Score:4, Funny)
Re:AOL (Score:2, Funny)
Probably you've sent them to http://www.nomoreaolcds.com/ [nomoreaolcds.com].
BTW: If I read the article that says aCD Rom is a bomb ready to explode I really wonder if we can sue AOL for deploying weapons of mass destruction. *eg*
Re:AOL (Score:2)
Re:AOL (Score:2, Funny)
Re:AOL (Score:2, Funny)
Re:AOL (Score:3, Interesting)
Dang! Where are all those AOL CDs when I actually WANT them?
Right here [nomoreaolcds.com].
Freeze the CD... (Score:5, Insightful)
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?
Re:Freeze the CD... (Score:4, Informative)
P
Re:Freeze the CD... (Score:2)
freezing things such as flowers in liquid nitrogen works by freezing the liquid water already in the flower, making them brittle.
However, if you've ever broken a plastic ice tray that's been in the freezer, you know that plastics are more brittle at lower temperatures... but it's not freezing.
Re:Freeze the CD... (Score:2, Informative)
Re:Freeze the CD... (Score:4, Funny)
Do I win it now?...
Re:Freeze the CD... (Score:2)
Trashed (Score:2, Funny)
Actually it probably makes sense considering he also has a "Chemlabs" page he was probably stoned at the time.
__
Cheap Web Hosting [cheap-web-...ing.com.au]
Jackass for geeks (Score:5, Funny)
-Shane
Pointed Out Already (Score:4, Informative)
Wrong. (Score:3)
Re:Pointed Out Already (Score:2)
Hmm... (Score:5, Funny)
How do we know how fast it was spinning? (Score:5, Interesting)
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.
Re:How do we know how fast it was spinning? (Score:2)
Re:How do we know how fast it was spinning? (Score:4, Interesting)
I have a few spare Radio Control car electric motors that have TONS or torque. I bet I can get the CD to spin at nearly thier top speed which is somewhere between 25k-40k depending on the motor. I've broken wooden airplane propellers on them trying to build thing before.
You can get some of them pretty cheap (25-40 dollars for the motor, 15-25 for a mechanical speed control). Lots of uses for a high torque, high RPM, motor.
Re:How do we know how fast it was spinning? (Score:2)
Plus, you have a very useful tool -- it's probably the most useful woodworking tool you can own.
While watching the movie... (Score:5, Funny)
You'll shoot your eye out!
Other good uses for CDs (Score:5, Interesting)
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...
Full Text... poor server... (Score:5, Informative)
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
This guy is going to get pissed (Score:5, Funny)
I'm safe (Score:2)
Here's a quote from the manual of my CD-RW drive:
The PlexWriterâ(TM)s reinforced tray bezel and drive bezel can resist the escape of the disc or disc fragments in the event of disc failure at this high 48X speed.
I knew it was worth paying the extra for the Plextor. Although such an event would almost certainly wreck the drive, it would still be a pretty cool story.
This picture is priceless (Score:5, Insightful)
Re:This picture is priceless (Score:2)
Well, as long as the Dremel is kept pretty still, all the exploding fragments will move outward, in a circle, from the bit. As long as his POV was perpendicular to the CD, he should be safe from being immediately punctured. Of course, shattered CD parts bouncing off of nearby walls is another matter entirely.
Re:This picture is priceless (Score:2, Interesting)
Definitely. Why are these guys wearing sunglasses? To look cool probably. The protection effect against high-velocity CD fragments is negligible. Still, it might help against secondary hits, which bounce off walls. The primary shrapnel goes off radially, so you can control it pretty good.
Anyway, these people seem to have too much time on their hands :-)
From the blog of Sam Barros... (Score:5, Funny)
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...
Page counter (Score:4, Funny)
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
Here's the MPEG (Score:5, Funny)
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
Newbies (Score:3, Funny)
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
How fast, again? (Score:2)
Just how fast is "a couple tens of thousandths of rotations per minute"??
St Anger (Score:2, Funny)
Revolution X (Score:2)
Re:Revolution X (Score:2)
The idea was that anonymous bug-eyed thugs in bad ninja costumes has, for reasons unknown, decided to deploy a huge army whose goal was to enslave everyone -- or perhaps just outlaw rock 'n roll, I was never too clear on this point. The hero (the player) had to blast his way through levels full of these guys a
Building an unreal tournament Ripper (Score:2)
And the whole structure should be built on a trolley and two columns where one column carries the trolley and the other touches and pushes the base of the CD at one end. Big rubber bands can hold the trolley holding the dremel and CD with a latch, and once the CD is doing well at high speeds, release the latch to fire the trolley and watch the CD disconnect
CD's (Score:2)
I'd like to build a few hanging geometric things out of CD's and have not yet found a good way to cut them reliably and accurately. I've tried various kinds of saw, craft knives and the like, hot objects, scoring and bending till they break and so on. Getting a couple good cuts is easy - getting a bunch of accurate shapes is a bit tougher.
Re:CD's (Score:2, Informative)
-Ab
To drive cats insane... (Score:2, Funny)
Re:Other uses for AOL CDs (Score:2, Funny)
Re:You don't need that much speed (Score:2)
Suchetha
Got chased by one... (Score:2, Interesting)
Re:sell it as art (Score:2, Funny)
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!
Re:CD's as weapons (Score:4, Funny)
...
....because, you know, it might be time for an upgrade.
Re:Before there were CDs (Score:2)