Alt-BEAM Archive

Message #09095



To: beam@sgiblab.sgi.com
From: Jonathan D Rogers chessmaster14@juno.com
Date: Wed, 12 Jan 2000 08:06:17 -0500
Subject: [alt-beam] Re: pancake motors


OK, let me make sure we're on the same page with the pancake motors here.
I'm looking at the guts of a 5 1/4" drive right now, and I see two motors
of interest-one of them is pretty big, and it essentially a big flat
magnet mounted on a circuit board with driver circuitry and a bunch of
coils under the magnet.
Now, there's also another, smaller DC motor that is still quite flat, but
somewhat smaller, and not on a circuit board. It's got 5 wires, so it
must be a stepper.
So, which one of these are you referring to?
I have also seen "board motors" like this in the many VCRs I've taken
apart.
And they're in all drives, basically, just in different sizes.
It seems to me that since there's drivers for the board motor on the
board, how hard could it be to run the thing?

jonathan

p.s. why is everyone whining about driving stepper motors? wouldn't it be
simple to interface to a microcore, bicore, etc. on the TTL level to a
stepper driver circuit?



9096 Wed, 12 Jan 2000 08:44:55 -0500 [alt-beam] yet more motors beam@sgiblab.sgi.com Jonathan D Rogers OK, I just dismanled a pretty ancient CDROM drive, a Sony CDU-33A, and I
think I struck gold. There's one of those motors on a board I've been
talking about, but the really good part is a tiny DC motor, not a
stepper, that moves the transport. The body is about 3/4" long, and the
motor has flat sides, but other than that it resembles a pager motor.
Except for the high-quality shaft encoder that's mounted on the arse end
of the motor!!! The thing is connected with one of those printed-circuit
cables, though, so I don't want to take it off until I know whether I
should.
But it looks very, very nice.
And I have another one of thses drives, too.
I'll see if I can get a picture of it with my dad's digicam for the
list...


jonathan

p.s. there is also a cute little DC solenoid in here, Elmo...very
small...



9097 Wed, 12 Jan 2000 09:24:53 -0500 [alt-beam] Photovore Performance? beam@sgiblab.sgi.com "Dye, Roy" What performance, in terms of time to charge and popping distance, could
one expect from a typical solar powered photovore?

I have just built my first photovore utilizing a 1381SE, 3766 solar
cell, and two pager motors from Solarbotics. It takes about 20s on my
workbench to charge and it moves about an inch per pop. In direct noon
sunlight, it fires about every 2 seconds. Is this typical?

Roy


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