Instructables

Step 2: Rip apart the DVD-Roms.

All you need from the DVD-Roms are the stepper motor assembly and one laser diode. I had a bit of bad luck and found that one of my DVD-Roms had a plastic assembly that would be very hard to work with. Thus I ripped apart three DVD-Roms and only used parts from two of them. It is pretty strait forward and most DVD-Roms I have opened works more or less the same way.

After removal of the screws at the bottom of the drive you can lift it of like a lid. Underneath you will most likely find two circuit boards and none of them are any use to us. But remember to salvage other useful parts that can be used for other projects. For example under the front circuit board there is a small dc motor worth saving. This is when it is time to remove the front together with the front of the tray; the front comes loose after you pull out the tray (just use a hairpin and the small hole in the front). The next step can include some screws and/or mild force. Remove the two circuit boards. Be careful with the ribbon cable to the stepper motor. If you turn the DVD-Rom right side up and remove the cover, you should find what we are looking for, the stepper motor assembly. Remove the screws and just lift it out.

Now that we have the assembly out it needs to be cleaned up a bit. Remove the spindle motor, it could be useful but I feel they are hard to drive and thus don't keep them. They are usually hold in place by three very small screws but sometimes they are part of a larger assembly so be careful that removing it won’t compromise the two rods holding the lens.

The lens is another story, just remove it best possible way, we need a smooth surface to attach other parts to later. Be careful to not harm the DVDR laser diode. It can come to good use if you don't want to buy a new powerful laser later. See the next step.

 
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gierszi2 years ago
Hi everybody,

I was thinking about using f.e. layada motorshield instead of use 2 easydrive stepper. Do you think it is possible?

the second question for elabz:
Did you manage to make driver with elements from cd-rom board?
kosme3 years ago
Do you think I could use CD-Roms instead of DVD-Roms??
lperkins kosme3 years ago
All the CD-ROM drives I've taken apart have a low-geared, regular motor, not a stepper motor. So they wouldn't work particularly well for this project. The rails and drive are still nice if you need something to slide back and forth, but you can't be nearly so precise about where it stops.
elabz3 years ago

Before you throw those PCBs out - there could still be usable parts on it! At least the regulator IC needed for the laser driver circuit is always there. It's usually a LM1117 - a low-dropout version of LM317. It's rather easy to remove and reuse, too.

I also find it handy to desolder and reuse the 4-pin ribbon connectors for the motors. They can help keep the installation tidy and modular. Also, some designs allow to reverse direction by just flipping the motor cable. Much easier than re-solder if you got your windings reversed.

Needless to say, since the drive uses the stepper and the laser that we're stripping from it, it already has the driver ICs for both! Unfortunately, they are in a really tiny surface mount form factor, really hard to desolder and reuse. But if someone's feeling adventurous, I've looked at some datasheets of the driver ICs and they are incredibly powerful little chips. For example, the laser driver can modulate the laser on command from the MCU based on 4-bit digital input. The stepper driver (it's usually an IC that drives ALL THREE motors used in a DVD drive) only needs the step and direction commands - it does the sequence by itself. Sort of like the Easydriver used in Groover's project but it's already there and it's normally going to trash . What a waste! One of those days I'm going to gear up with a better soldering station and attempt to reuse that stepper driver IC from the drive itself.    
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