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Transplanting Hard Disk Platters?
- Thread starter Mac128
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I've pulled tops off of several brands of hard drive, to varying degrees of success.
Quantums are really easy, because they're (usually) the toilet-bowl design with the stamped metal top that easily screws down, with no odd protrusions into the lower bit of the case. Most of them work fine with or without their tops, but some single-platter drives won't operate properly exposed because of the peculiar implementation of the AirLock system.
Conners can be problematic, as it's easy to hit the platters when removing the bowled top casing. Other than that, most of the ones I've run exposed have exhibited no problems. In fact, several have run without their tops when they wouldn't run at all otherwise.
Seagates are a mixed bag: some work fine, some don't. Medalists are usually fine, but (sub-10GB) Hawks and Barracudas typically freak out and won't even spin up if the top is off. U Series drives usually work nudified, but they're difficult to disassemble with both the sealing tape and the shock-absorbing "condom".
WDs work fine open, but older ones are almost always sealed with tape, which is close to impossible to remove in one piece. When I reseal the taped drives (of any brand), I use thin strips of duct tape.
IBMs are also very cooperative, even the notebook models. A couple of odd UltraStars are the exception, because their casing is split down the middle.
Fujitsus, Maxtors, MiniScribes, and Toshibas typically run exposed well with no real issues.
As for positioning systems, there have been many different approaches over the years. Early drives often just used stepper motors, counting the steps the motor moved the heads to tell where on the disks they were positioned.
Some later drives, Quantum and Sony for sure, used an optical tracking system. These drives employed a small attachment to the armature, a small piece of glass or plastic with a bar code-like grid on it, read by an infrared LED and pickup. The electronics would count the movement of the gradients on the tracking grid, and thus keep track of where the heads were positioned.
As a side note, on Quantum ProDrive LPS drives (from 40 to 230MB, employed quite frequently in Macs), the little "tick-ticka-tick-ticka-tick" sound emitted every 15 to 30 seconds is the sound of the electronics recalibrating the heads, just in case it missed counting a gradient.
Then, modern drives use embedded servo information. Some drives would dedicate an entire platter to maintaining servo information, where others embed the servo data alongside the usable data.
I've never tried swapping platters or head assemblies, though, as most of my problems have been easily solvable (stiction, damaged PCBs) or unsolvable (extreme shock or water intrusion).
As for swapping PCBs, older drives (<4GB) are picky about firmware revisions and all, but modern drives work just fine so long as the boards are from the same model and capacity.
Quantums are really easy, because they're (usually) the toilet-bowl design with the stamped metal top that easily screws down, with no odd protrusions into the lower bit of the case. Most of them work fine with or without their tops, but some single-platter drives won't operate properly exposed because of the peculiar implementation of the AirLock system.
Conners can be problematic, as it's easy to hit the platters when removing the bowled top casing. Other than that, most of the ones I've run exposed have exhibited no problems. In fact, several have run without their tops when they wouldn't run at all otherwise.
Seagates are a mixed bag: some work fine, some don't. Medalists are usually fine, but (sub-10GB) Hawks and Barracudas typically freak out and won't even spin up if the top is off. U Series drives usually work nudified, but they're difficult to disassemble with both the sealing tape and the shock-absorbing "condom".
WDs work fine open, but older ones are almost always sealed with tape, which is close to impossible to remove in one piece. When I reseal the taped drives (of any brand), I use thin strips of duct tape.
IBMs are also very cooperative, even the notebook models. A couple of odd UltraStars are the exception, because their casing is split down the middle.
Fujitsus, Maxtors, MiniScribes, and Toshibas typically run exposed well with no real issues.
As for positioning systems, there have been many different approaches over the years. Early drives often just used stepper motors, counting the steps the motor moved the heads to tell where on the disks they were positioned.
Some later drives, Quantum and Sony for sure, used an optical tracking system. These drives employed a small attachment to the armature, a small piece of glass or plastic with a bar code-like grid on it, read by an infrared LED and pickup. The electronics would count the movement of the gradients on the tracking grid, and thus keep track of where the heads were positioned.
As a side note, on Quantum ProDrive LPS drives (from 40 to 230MB, employed quite frequently in Macs), the little "tick-ticka-tick-ticka-tick" sound emitted every 15 to 30 seconds is the sound of the electronics recalibrating the heads, just in case it missed counting a gradient.
Then, modern drives use embedded servo information. Some drives would dedicate an entire platter to maintaining servo information, where others embed the servo data alongside the usable data.
I've never tried swapping platters or head assemblies, though, as most of my problems have been easily solvable (stiction, damaged PCBs) or unsolvable (extreme shock or water intrusion).
As for swapping PCBs, older drives (<4GB) are picky about firmware revisions and all, but modern drives work just fine so long as the boards are from the same model and capacity.
Once I had to recover data from a harddisk drive that was submerged into water by accident. Water was gurgling inside the case. Never attempt to connect a drive in this state! To repair the drive I removed the metal top and used plenty of deionised water to rinse all the innards of the drive thoroughly. Afterwards I put the drive into a plastic bag, accompagnied with some bags of drying agent (silica gel) and left it for several days. Once the drive mechanism was dry I rotated the platters a bit to resolve stiction. After reassembling the case and connecting the drive to a computer it spun up and allowed to copy the complete contents to another drive. This harddisk was quite usable for a few week, still, until the water initiated corrosion caused fast growing defects.
On the other hand, think for a moment of fume cupboards in chemical laboratories, or better, laminar-flow microbiological work hoods. Given that the work to be protected is at the bottom of the contained space, horizontal airflow above it is protective if the size/mass/velocity of contaminating particles is such as to prevent them from falling to the bottom of the space within the time taken for the air's transit of the space.
Still air demands total filtration/cleanliness, or the work can be contaminated by the effects of gravity on contaminating particles. Laminar flow allows for some contamination to be endured if the mathematics of risk are correctly evaluated. In conjunction with filtration of the inlet air, it can work a treat.
de
Yes -- a lot certainly depends on the location (and nature) of the contaminants. In a typical home lab (yes, I am making assumptions here, but ones based on visits to a good number of home labs; dust seems to be a common companion), there's likely to be a fair amount of deposited dust on many surfaces. Blowing air in those environments virtually assures a redistribution of that dust, to the detriment of the disk platter. In still air, the rain of dust will be much more moderate, given the assumptions.
I agree that the best arrangement is filtered air, with a gentle circulation to scrub out particulates that evolve within the protected space. Semiconductor fabs are arranged this way, with the primary source of contaminating particulates in that situation -- humans -- properly isolated within protective suits.
I wish I had observed more interest in this thread earlier...
The first removeable disk drive that I used was the DEC RL02 pack, followed by various Syquest designs. I never met an Iomega design before the Zip drive. But from all of those drives we can learn a little about how a home brewer might build an enclosure in which to disassemble and reassemble disk drives. This is a first pass at an idea, so corrections are welcome.
1. Build a box that is fully enclosed (ie capable of sustaining slightly above atmospheric pressure without leaking). The walls of the box need to be "closed" (ie the fabric of the box will not generate dust in itself). The box needs a filtered air output (easily cleaned) and a chemically clean pressure system (ie no lubricant leakage) which is again filtered. Flow for the pressure system must be laminar, particularly at the inlet and outlet to the box.
2. An enclosed box is useless to work in. So you are going to need external/internal gloves (as seen in all videography of nuclear power plants) that allow you to access the box from outside.
3. The box will need a decontamination zone by which tools can be introduced. The same rules apply for the decontamination zone as for the enclosed box.
4. Insert your drives and run the pressure system for hours to drive dust out of the system.
5. To clean the box out initially, run the pressure system high to generate turbulence. After that, don't crank up the positive pressure because you may recirculate undisturbed particles.
The first removeable disk drive that I used was the DEC RL02 pack, followed by various Syquest designs. I never met an Iomega design before the Zip drive. But from all of those drives we can learn a little about how a home brewer might build an enclosure in which to disassemble and reassemble disk drives. This is a first pass at an idea, so corrections are welcome.
1. Build a box that is fully enclosed (ie capable of sustaining slightly above atmospheric pressure without leaking). The walls of the box need to be "closed" (ie the fabric of the box will not generate dust in itself). The box needs a filtered air output (easily cleaned) and a chemically clean pressure system (ie no lubricant leakage) which is again filtered. Flow for the pressure system must be laminar, particularly at the inlet and outlet to the box.
2. An enclosed box is useless to work in. So you are going to need external/internal gloves (as seen in all videography of nuclear power plants) that allow you to access the box from outside.
3. The box will need a decontamination zone by which tools can be introduced. The same rules apply for the decontamination zone as for the enclosed box.
4. Insert your drives and run the pressure system for hours to drive dust out of the system.
5. To clean the box out initially, run the pressure system high to generate turbulence. After that, don't crank up the positive pressure because you may recirculate undisturbed particles.
If it's all for self-entertainment or for learning, more power to the elbow of the experimenter. If it's for a panic-stricken recovery of unbacked-up data (naughty, naughty), it's understandable, even if it is, as Bunsen writes, perhaps overkill. But a one-shot recovery must work first time, and who can say in advance how elaborate that one shot needs to be?
de
de
Agreed, overboard for a quick data exchange. Like others, I've run naked drives for experimentation and it is quite hard to deliberately kill them. But original hard drives are becoming difficult to find, so a home brew clean room environment is worthy of consderation. Would you want to rebuild a Lisa widget or a Profile or an ST-506 without making the effort to maximise success?
one thing about changing platters on a voice coil drive.
if its a multi platter drive, FORGET IT. its easier to change the heads than the platters. because if you undo the platters, if the two platters slip any at all (which they will, without a piston compressor or platter tool). you will loose the cylinder and servo track alignment, and there goes your possibility to recover data... down the drain.
so you need to watch for that. its far far easier to change the head/actuator and swap between two identical drives than it is a multi platter.
the tolerances between platter to platter alignment tracking and head pressure bering is a micron or less.
if its a multi platter drive, FORGET IT. its easier to change the heads than the platters. because if you undo the platters, if the two platters slip any at all (which they will, without a piston compressor or platter tool). you will loose the cylinder and servo track alignment, and there goes your possibility to recover data... down the drain.
so you need to watch for that. its far far easier to change the head/actuator and swap between two identical drives than it is a multi platter.
the tolerances between platter to platter alignment tracking and head pressure bering is a micron or less.
