Cracking Open a Seagate 50 MB RLL drive

Front view

This fits into a 5.25 bay in the PC.

Warning!

This will have to come off...

Rubber bushings for the mount points

I found this cool.

Size comparison

As a visual point of reference, I give you an SD card. As another unintentional point of reference, this little SD card holds 10x what our Seagate here holds, and faster.

The back

The MFM tabs.

Fat foam seal

Interesting fat foam seal between the cover and base. Cheap looking, even.

Actuator motor

At the time that I took this picture, I was unsure of what this was. It turns out to be the actuator motor.

Ground for drive motor

This appears to be the ground for the drive motor -- like the brushes in an electric motor. The blue plastic tab in the background was glued to the circuit board on top of it, and held the tab down.

Drive motor and actuator motor

Here we lift the board from the body and get a good look at the bottom of the drive motor, and the actuator motor. There were a total of three connections to the board one for the drive motor, one for the actuator motor, and one for the ribbon that runs the heads, which we'll see a bit better later.

Circuit board

The board next to the body.

The activity LED

Taking the torx screws out of the cover

But first I take off the label

Don't ask me why I feel compelled to do it...

It's dark in there

Can't see much. Disappointing. It did smell like new electronics, though.

Cracking it open, as they say

Cracked

I was kind of surprised to see only two platters. Interesting actuator mechanism.

Filter/dessicant

The filter/dessicant looks like a cartridge that they expect to be replaceable.

Actuator mechanism

A good look at the actuator mechanism.

Actuator

This, to me, is the most interesting part of the device. The actuator is driven by opposing metal bands. Over in the next three pictures, you can see how it winds and unwinds...

Actuator

Midway through its cycle.

Actuator

...And at the end. You can see the torx screw here that must have been used to do some kind of final adjustment during assembly.

Head assembly

A good look at the head assembly.

Actuator extended

This view shows how the actuator extends in between the two platters when fully extended. (I should have had the platters in focus here...)

Irma goes for a ride

Well, I've always wanted to power up a big HDD when disassembled, but never got around to it. Here is my big chance. It was going to be hard to demonstrate the platter spinning in a picture, however, so -- I give you 'Irma', my eight-year-old daughter's doll. Irma is going for a ride. I glued her feet to the center of the platter for our entertainment.

Irma goes for a ride

On goes the power, Scottie. She spun for about 6 seconds, when the whole assembly began to shake violently and try to walk off of the bench. Just as I went to hold it down...

Poor Irma

The aftermath: after a head-first trip into the wall, Irma is face down in a pile of hardware.

Removing the front cover

Okay, on with the project. Here I'm taking off the "front cover." Notice how the ribbon for the heads was just pinched in between the cover and the seal.

Removing the adjustable stop

There seems to be a lot of adjustable parts.

Taking the actuator bands apart

I wanted to show how thin these were, but they didn't show at all in the picture. I guess that says plenty. They were .0015" each.

Another picture of the bands

Taking off the actuator

Mounting screw

The mounting screw appears to be one piece and pressed into the bearing.

Head closeup

A nice view of the r/w head, This is a fairly hi-res image, if you save and zoom in on it, you can see the little coil at the tip.

Taking the platters apart

The next four pictures show each step of taking the platters apart. The arrows were initially intended to show the rotation when spinning -- but then there was Irma....

Platter 1

Aluminum spacer

Platter 2

Motor

Here is the motor itself, a Nidec. I've seen that brand in another HDD; I'm sure that is a common brand.

Motor bottom

A good look at the bottom of the motor before removal. Also a good look at the carbon button.

The motor removed

Taking out the actuator motor

Plastic seal

I noticed a thin plastic seal for the drive motor that I didn't see before.

Actuator motor

Now lets see what makes this actuator motor go.

Motor cover

I had to pry the black cover off, and there was a wavy washer in the bearing cup to keep pressure on the bearing.

Actuator motor

This is cool. It explains the "notchy" feel of the motor. Multiple coils and notched pickup.

Taking the plastic cover off

Actuator motor

Nice. I'm no electrical engineer, but it looks like there are two sets of controls -- a start and stop signal for each direction. If you look closely, you can see where each wire taps into its respective coil.

Another picture of this very cool motor

Maybe someone out there knows exactly what this type of motor is called?

And another

Taking apart the motor

After the coil came out, it put up a bit of a fight.

The coil by itself

The motor, cracked open

The Seagate 50 MB RLL drive, cracked open

And finally, the whole drive blown up. If you are wondering, yes, it went back together and ran as it did before, though the heads made a bit of noise, and I'm pretty sure that I wouldn't try to store anything important on it, even if I did have the right controller.