Author Topic: Cannibalising a minidisc for parts for a automaton  (Read 480 times)

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Offline banjobillTopic starter

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Cannibalising a minidisc for parts for a automaton
« on: April 18, 2024, 01:37:05 pm »
Hi, I'm new to the forum and new to electronics so apologies if I ask dumb questions.

I have an old Sharp Minidisc and before binning it I looked for anything I could re-use - I'm interested in making automatons.  There is a tiny motor and worm gear that positions the laser read/write head which looks like it could be useful.

Any suggestions on how to decode where power should be applied, how much, tracking down datasheets (next to no part numbers).  Or am I wasting my time?

Cheers
 

Offline ajb

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Re: Cannibalising a minidisc for parts for a automaton
« Reply #1 on: April 18, 2024, 02:28:41 pm »
Welcome to the forum!  Automatons are cool, would be neat to see what you come up with.  There's an art museum near me that has a whole exhibit of wooden mechanical gadgets, that's my favorite part of their collection.

Mass produced consumer goods like this will use a lot of custom (or semi-custom) mechanical parts, so are are not likely to find any datasheets.  You'll have to do some reverse engineering.  The motor will almost certainly be either a simple brushed DC motor or a stepper motor.  The former will have two leads, the latter will have 3-5 leads.  There might be an encoder attached, which will have 3+ leads, or they might rely on the read head to provide position feedback to the motor relative to the data track.  Beyond that, we'd probably need to see some pictures to help figure out what's going on.

FYI, I've seen similar mechanisms to what you're describing out of CD/DVD drives being sold separately on Amazon/ebay as small linear actuators.  I can't find the right search terms now, but you might be able to find more of those mechanisms without having to cannibalize them yourself.
 

Offline banjobillTopic starter

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Re: Cannibalising a minidisc for parts for a automaton
« Reply #2 on: April 18, 2024, 03:53:52 pm »
Thanks for the info.  The motor is tiny - 14mm in diameter, 2mm thick.  It has 3 pins so I guess it's a stepper.  The biggest problem is attaching wires to the thing  :)

Any idea what voltage would be required?
 

Offline coromonadalix

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Re: Cannibalising a minidisc for parts for a automaton
« Reply #3 on: April 18, 2024, 04:10:56 pm »
i would say in a sense you loose your time,   you would need to practice on bigger parts ....

anyway

to automate any moving sliders, rotating gears etc ...   you need to find if there is a limit switch, an encoder wheel  etc ...   
the system needs to know where it is mechanically ... if your are at a position limit, and can only do a reverse or only do a forward   etc ... 

that's what we call feedback, position sensing, rotation speed sensing, rotation positioning with stepped motors, torque sensing  etc ..
 

Offline banjobillTopic starter

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Re: Cannibalising a minidisc for parts for a automaton
« Reply #4 on: April 18, 2024, 04:28:01 pm »
Good point!
 


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