CD-ROM Steppers for X-Y beds

So many people has already tried so many weird things, so before I go and try this for myself, I want to know if anybody already tried mounting and using the steppers from CD-ROM drives?

Hi Anton,
i have tried it and got a lot of trouble.
Even if you use an old 5,25 floppy stepper you get smaller size(Nema 14) with lower-powered torque.The screws are often M3 (must change to extreme long)and have to be used for both, assembling the stepper-parts and also fastening.(only remove one at a time!)
Sometimes they are powered with 5 volts.
Erich

I remember seeing this thread on the Arduino forum [www.arduino.cc]

The most relevant paragraph:

Quote

Now. DVD ROM motors. The average DVD drive yields three motors. There is usually a DC motor for moving the tray. There is a DC or stepper motor for moving the optical head. And there is usually a three-phase spindle motor for spinning the disk. It's the last one that people are usually interested in, since they tend to be pretty powerful, and ... unusual. There is a lot of information on using such spindle motors, either as-is or "modified" in the RC plane community, but they tend to rely on commercial speed controllers (or dedicate entire arduino-class electronics to just running the motor.) This isn't out of the question; you can get such speed controllers for less than $15, and you control them pretty much like RC servos.) In THEORY, you can also drive them like stepper motors with one-too-many or one-too-few coils, and I've always thought that there ought to be a pretty simple circuit that would let a microcontroller drive them in a rather slow and jerky fashion, but I don't think I've even seen one (Another problems is that such motors tend to be pretty power-hungry, even if you're just trying to make them hold a position...)

The old 5.25 FLOPPY disk drives used to have steppers. I'm under the impression that hard drives & 3.5 floppy drives don't.

But be warned that all this is head knowledge - I've not actually tried it myself

They're BLDC motors- basically 3 phase AC permanent magnet motors with a trapezoidal current profile rather than sinusoidal, and optimised for speed rather than torque.

Think 3-coil stepper with about 12 steps per rev

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Wooden Mendel
Teacup Firmware

I too have been taking broken CD/DVD players/drives apart for 'spare' parts. The first really suprised me as all 3 motors were DC.

So, the question arises whether a XY bed can be motorised from the (geared down) DC motors with some feed back of position? The 'obvious' positional feedback would be an inverter optical mouse, pointing at the underside of the bed.

The next conceptual step is to use an audio amp (with input DC block removed) to drive said DC motors, directly from the ouput of the PC's audio card. A former colleague mentioned that he was using Arcam Delta Amp (which have DC input) for some servo motors drive at one time....

Mungewell.

Sorry, I believe I have been a bit unclear in my question. From my investigations, studying on the net and taking one apart to look things over, it appears that I have 1 and 1/2 stepper motor.

The real stepper motor looks very small, approx 18MM diameter motor housing and a 3MM shaft diameter.

The "half" stepper motor is the spindle motor, which is a brush less dc motor, which probably could be rigged to behave as a stepper with a feedback look using the three attached Hall effect sensors.

The real question - I meant was - X-Y seems to me to require the least amount of torque, and I was wondering if anybody had attempted to see if one or the other actually had enough torque be used for moving the X and Y beds.

maybe the motors out of old printers would be better?

anton, pretty sure you would need to gear them down for the sake of both torque and precision.

[www.rcgroups.com] has a wealth of information on these motors.

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Wooden Mendel
Teacup Firmware

I happen to have one 8 inch floppy drive :-D Let's see what it has inside ;-)

I have three steppers from

2 from old 5.25 hard drives NEMA 14 0.9/400 step

1 from a 5.25 Disk drive NEMA 15 feels like 400 step

I will be trying them on my recycled bits Mendel build.

As for 3.5" disc drives look at Spark fun or search Beam they are tiny NEMA 05 steppers with their own long spiral drive shaft.

Printers have usualy have 1 Tin can stepper that drives the paper usual 48 step 7.5 Degrees. The head is driven by DC motor used as a closed loop servo with encoder strip like a long see thru barcode and a tiny timing belt.

Sanners have the same stepper 48 step 7.5 Degrees with small gear chain. They also have tiny timing belt very much like the printer timing belt.

I will also try and reuse these on my recycled bits Mendel build.

Sofar all the scanners I have taken apart have a Mitsumi stepper with identical gear chain assemblys. All kinds of makes from HP to unheard of names.

Printers have only been Lexmark they also have the same Mitsumi stepper I bought 4 Lexmark in end of line sale (dirt cheap) in ASDA is the UK part of Walmart .

Price was black & colour ink cartridges half price with free printer to hack.

Edited 3 time(s). Last edit at 02/11/2010 08:01AM by BodgeIt.

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This post is rather old but comes up on the first page google spits out. So maybe this helps others:

Not all cd/dvd rom drives have steppers. I took apart 6 drives and only 2 of them had steppers. The rest had DC motors.
A 3,5" drive I took apart had a small stepper too.

From my experience they can have 20 or 53.33 steps per rotation.