Re: Hard Drive Motors, RSGs and Stuff

["Christopher Boden" <chrisboden-at-hotmail-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

If the specs for a typical hard
>drive are to be believed, these motors are capable of atleast 3600 RPM.

3600 is easy, current drives run around 7200 and up, with the fastest SCSI I 
have seen at 10,000RPM.

You will need 12VDC to run the motor and 5 VDC for the electronics, they are 
VERY touchy to noise and ripple.

Remember, the plattens are coated with Iron Oxide (that's why they're brown) 
and are conductive. If you're lucky you'll be able to find an old MFM drive 
(like 5MB or so). It will weigh at least 5 pounds and not have the standard 
IDE connector, but a card-edge type instead. These mostly had seperate 
stepper motors instead of the current trend for a card mounted motor with 
the coils mounted on a card (surface mount, kinda) and the drive being 
through a magnet mounted on a shaft.

If you do a little hunting, try to find an old AS-400 mainframe or something 
similar. They have >100LBS hard drives that take up like 8U rack spaces. 
These drives work on 240VAC and the drive motors will spin happily on 110 
and have there own power supply units. We have tinkered with this idea for a 
while. With one of the large drives it should work. The plattens are about 
14"dia and have tons of inertial mass. The motors are VERY powerfull and 
maintain a rock-solid RPM and will live just about forever.

Christopher A. Boden Geek#1
President / Founder
The Geek Group
www.geekgroup-dot-org
Because the Geek shall inherit the Earth!

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