Alt-BEAM Archive
Message #06016
To: beam@sgiblab.sgi.com
From: "David Perry" davidperry@geocities.com
Date: Tue, 7 Sep 1999 08:23:59 +1000
Subject: [alt-beam] Re: CD-ROM read-head feet
The light that usually comes from lasers in cd devices is IR. Invisible to
the naked eye, yet still dangerous. These days with so many laser pointers
floating around people don't release the severity of a direct hit in the
eye. I've been hit a couple of times indirectly and a had a spot on my
vision for 1/2 hour. That was just from it bouncing off a window if i
remember correctly. Be very careful, lasers are cool (have you seen my
automatic laser light show assembly?) but can be very dangerous. Think of it
as lying on the beach while someone walks about and focuses the beam from a
magnifying glass at your eye. I had one of those lense assemblys too, very
strong magnets. I wrecked mine though (oops)
have fun,
David Perry
>This one has _got_ to have come up before, but it's new to me:
>I needed some tiny screws, and found some in the reading head of an old
>CD-ROM I had pulled to bits. Upon getting my screws, the head fell to
>bits . I started fiddling with the bits, and hooked them up with
>power.
>As you probably know, in addition to the motors, the lense's position is
>fine-tuned with coils and magnets. Playing with these, I found the head
>had quite a lot of freedom of movement, and quite a lot of grunt (very
>strong magnets, very fine wire, many winds). It can move up, down, left
>and right. IOW, hook it up to a microcore and you have a one-footed
>walker that can AFAICS do anything a two motor walker can. Hook it up to
>something with more states and it can do more (such as turn left or
>right). Even running the coils off a tiny 470uF cap was enough for them
>to twitch their metal casing off the ground. Use a battery and they
>practically leap...
>I took apart another head, from a different brand, and this one moved
>up, down, pivot left, pivot right - even more useful.
>
>I suspect, however, the easiest application is for BEAMish art - take
>the butterfly (or whatever) on a stick, put the stick on the head
>arrangement, and connect a standard audio plug to the coils (left
>channel to one coil set, right channel the other), plug it into your amp
>and watch the butterfly conduct an orchestra in stereo :-)
>(I suspect the butterfly will spend most of its time conducting the
>drums and ignoring the strings, but that's butterflies for you... :)
>
>Stick an LED on the end of the stick instead, or a laser diode, and have
>an annoying "light show" on the roof.
>
>Which reminds me - as far as I know, the light from CD-ROM drive laser
>diodes is invisible, but this doesn't sit well with the explicit laser
>warnings on the case and instructions not to look at the beam. Can
>anyone enlighten me as to what the story is?
Home