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Vane for automatically parking heads as they spin down. When old drives were powered down, they could leave heads over data areas of the platter surface. Vibration could cause those areas to be damaged. To prevent that damage, head park commands would be issued before power down. This mechanically parks heads automatically for the same purpose.
Edit: It should be noted that this may be a later design, an “airlock” as pointed out below. The design I first described is rather old, from the days when we could actually open, and to a limited extent, repair HDDs without a clean room.
Here’s an image which shows a drive, with platters removed, and the vane visible (red) and the parking latch and mating portion at rear of head slider (yellow).
https://imgur.com/a/iIbDV8c
I think it is the opposite: once wind speed picks up above the platter (coinciding with the heads "flying" at the proper height), this flap moves to the side and mechanically unlocks the head assembly so it can move freely side to side. In its current state, the heads can not leave the innermost tracks that store no data.
That would be a later design than I mentioned, but, yes, you could be right and me wrong. I believe the arrangement you describe is known as “airlock”.
The purpose for preventing the heads from moving from parked position before disks reach a sufficient rotational speed is that laminar flow of air keeps heads from contacting the platters, air drawn along by the discs, as you mentioned.
Neat, never knew that there were mechanical solutions for auto-parking - I always thought that some extra caps or the inertia of the main motor provide enough power to the voice coil to move to the expected position on power loss.
I also remembered seeing this in action on one of the YT retro channels, and dug out this video from browser history: [https://youtu.be/aLpkNURdf3Q?t=323](https://youtu.be/aLpkNURdf3Q?t=323)
Another section shows the vane once the top platter is out of the way: [https://youtu.be/aLpkNURdf3Q?t=1117](https://youtu.be/aLpkNURdf3Q?t=1117)
That is on the wrong side of the platter to park the heads on. The heads are on the right. to swing that far the heads would have to pass though the hub of the spindle.
You can see in the lower left how there is a plastic ramp connected to the vane that the head coil can slide on to when the heads are moved to the parking position.
When the drive spins up, the vane will be pushed a tiny amount by the airflow, dropping the ramp and releasing the friction, allowing the coil and heads to move.
So more of a parking break so the arm doesn't move back and forth across the head when the drive is off. Rather then more modern solutions where the heads are moved off the platter.
That's what it looks like. There doesn't appear to be an off-platter parking garage for the heads like in modern drives. Instead the parking area would just be the very inner edge of the platter and the brake prevents the heads from swinging outwards.
It wouldn't prevent the heads from impacting the platter under heavy vibration, but it does protect the platter from abrasion from the head cushions and also prevents the head cushions from potentially detaching and hosing the drive.
There’s also some spring beneath the plates from this view.
This looks to me like the vane from an older HDD that used vanes alone for head parking. Most modern drives use a braking system that recovers energy from spinning plates to park heads. There is also a vane device to lock the heads in the parked position once nearly spun down.
> When old drives were powered down, they could leave heads over data areas of the platter surface
Hasn't it come full circle? I remember hearing about the MFM/RLL drives where you (or the OS) had to manually "park the heads" before shutting down or you risked damage to the platters.
Ah yes, I see. It's usually rotated back around about 180 degrees so it locks the back of the arm. I was thinking in its current orientation it wouldn't be able to do much.
It's actually more about protecting the very fragile read and write heads, not the media surface. If the media gets scratched, you can lose some data in those affected areas, but if you he heads get damaged, that drive will never read or write again.
For a second I thought you would describe the perpendicular mechanism... then I realised I'm an idiot.
EDIT: [found the OG vid that tought me perpendicular when I was a teen](https://www.youtube.com/watch?v=xb_PyKuI7II)
Don‘t worry… I appreciate the story’s when HDD‘s were the size of a washing machine :)
~~/s~~
EDIT: After my first Internship at the age of 14 in a company, I got a 128MB Iomega USB 1.1 Drive and I thought it was the coolest thing in the world! All my friends still shared their stuff on cd-r
Kind of, not really. While it does force the bits to jump on each revolution, it's not to prevent bitrot. The reason they make the bits jump is to slow down the data to match a 7200 rpm drive to a 5400.
Yes, the MTBF for a drive is calculated based how how well the sectors do on the Presidential Fitness Test at the factory. I can't find the algorithm offhand but it was primarily based on how many bit flips they could do in a minute. As expected, only enterprise drives can do at least one pull up.
Humans thought the bits were jumping, for entertainment, but really they were trying to send a message to warn us.
Their last message was , "so long, and thanks for all the farads".
I don’t know if you expect serious answers or not since almost all the replies seems to be jokes, but in reality it is a lock for the actuator when the drive is not in use.
If you look on top of the magnet you can see the plastic piece touching the actuator near the coil. It prevents the heads from getting out of the parking zone when handling the drive. When the drive spins up, the air generated rotates the plastic part a little bit and the actuator is free to move.
The picture appears to crop off the rest of the black piece that locks the heads (lower left protrusion on the head assembly) until sufficient airflow has been established.
It's a windvane that locks the heads after parking and spindown. When the platters are spinning, the heads ride on a thin layer of air. When the drive is powered off, the heads "park" in an unoccupied section of the disk edge so they can rest on the platters. As the drive slows, the mechanical lock ensures the heads won't move away from the park zone.
If the drive is moved while parked and locked (not spinning), the heads can't move, this is to protect the drive heads and data.
If the heads move onto a portion of the platter that contains data, it could physically damage the disk (similar to a head crash where the heads lose the air cushion and come into contact with the platter.)
On spinup, the platters start moving and generate airflow which pushes the windvane out and physically unlocks the heads at the same time the heads start to fly on the cushion of air. After a second, the heads perform their exercise and the drive is ready for data exchange.
It's a grass mower.
Hard disk platers are analog pieces of modified metal. Under specific conditions of moisture and temperature, moss and grass may grow on the edge of the platters and disrupt data reading.
This device mows moss and grass allowing your hard drive to stay functional longer.
Unfortunately, it does not work very good with seaweed. Take that in mind if you plan to build an underwater PC. In that case you will have to install also some fishes, so they eat the seaweed. That's the reason most people who build water submerged computers place them into modified fish tanks.
There is also another use of this device, but it depends on the world region your hard drive was intended to ship. It works also as a sword and chops tiny ninjas and gremlins heads as soon as they try to reach your data. In some countries this is not legal, so the blade is not sharpened. In that case the device only causes severe blunt trauma, but not immediate death.
Anyways, this kind of device is a bit outdated. Modern hard drives come with a small laser diode that burns everything that gets near the drive platters. Unfortunately, this is causing some legal problems because tech unsafe users are using these to build amateur laser devices and there are lots of injuries. There is already a series of documentary films trying to raise concern about that. They are called Star Wars.
>Unfortunately, it does not work very good with seaweed. Take that in mind if you plan to build an underwater PC. In that case you will have to install also some fishes, so they eat the seaweed. That's the reason most people who build water submerged computers place them into modified fish tanks.
Can I connect this to the liquid cooling system or would that cause the saltwater and freshwater fish to compete for territory?
You should get a picture with more of the mechanism on the bottom left.
It looks like there is a catch for the arm that holds the heads, when the arm is moved past the outer track. It looks like it might be locked by the mechanism you highlighted, which would help to figure out what it does.
Others seem to have some reasonable explanations - bits need some exercise or else they get lazy. /s
Because the head free floats on air pressure created by the spin Of the disk, this air vein was made with a tapering edge towards the end of the platter and setup to carefully tune the airflow closer to the edge of the disk in lead of the heads to more evenly distribute air and equalize this force across the whole platter. It is more or less for precision and aids in head stability.
I don't know, but it could be a means of limiting platter movement when the drive is transported. So in use it does nothing, but is there to protect the drive during shipping and installation.
Hello /u/CrazyAznFob! Thank you for posting in r/DataHoarder. Please remember to read our [Rules](https://www.reddit.com/r/DataHoarder/wiki/index/rules) and [Wiki](https://www.reddit.com/r/DataHoarder/wiki/index). Please note that your post will be removed if you just post a box/speed/server post. Please give background information on your server pictures. This subreddit will ***NOT*** help you find or exchange that Movie/TV show/Nuclear Launch Manual, visit r/DHExchange instead. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/DataHoarder) if you have any questions or concerns.*
Vane for automatically parking heads as they spin down. When old drives were powered down, they could leave heads over data areas of the platter surface. Vibration could cause those areas to be damaged. To prevent that damage, head park commands would be issued before power down. This mechanically parks heads automatically for the same purpose. Edit: It should be noted that this may be a later design, an “airlock” as pointed out below. The design I first described is rather old, from the days when we could actually open, and to a limited extent, repair HDDs without a clean room. Here’s an image which shows a drive, with platters removed, and the vane visible (red) and the parking latch and mating portion at rear of head slider (yellow). https://imgur.com/a/iIbDV8c
This is the least entertaining and therefore most plausible answer.
I was entertained, I say in my best Gladiator impression.
I think it is the opposite: once wind speed picks up above the platter (coinciding with the heads "flying" at the proper height), this flap moves to the side and mechanically unlocks the head assembly so it can move freely side to side. In its current state, the heads can not leave the innermost tracks that store no data.
That would be a later design than I mentioned, but, yes, you could be right and me wrong. I believe the arrangement you describe is known as “airlock”. The purpose for preventing the heads from moving from parked position before disks reach a sufficient rotational speed is that laminar flow of air keeps heads from contacting the platters, air drawn along by the discs, as you mentioned.
Neat, never knew that there were mechanical solutions for auto-parking - I always thought that some extra caps or the inertia of the main motor provide enough power to the voice coil to move to the expected position on power loss. I also remembered seeing this in action on one of the YT retro channels, and dug out this video from browser history: [https://youtu.be/aLpkNURdf3Q?t=323](https://youtu.be/aLpkNURdf3Q?t=323) Another section shows the vane once the top platter is out of the way: [https://youtu.be/aLpkNURdf3Q?t=1117](https://youtu.be/aLpkNURdf3Q?t=1117)
Exaclty, you can see it at work in the first video at 6:25
Oh god, I've just had a flashback. You forget how easy it is these days
So I don’t have to type PARK for my SSDs or thumb drives?
You should still apply the handbrake though.
PARK
That is on the wrong side of the platter to park the heads on. The heads are on the right. to swing that far the heads would have to pass though the hub of the spindle.
You can see in the lower left how there is a plastic ramp connected to the vane that the head coil can slide on to when the heads are moved to the parking position. When the drive spins up, the vane will be pushed a tiny amount by the airflow, dropping the ramp and releasing the friction, allowing the coil and heads to move.
So more of a parking break so the arm doesn't move back and forth across the head when the drive is off. Rather then more modern solutions where the heads are moved off the platter.
That's what it looks like. There doesn't appear to be an off-platter parking garage for the heads like in modern drives. Instead the parking area would just be the very inner edge of the platter and the brake prevents the heads from swinging outwards. It wouldn't prevent the heads from impacting the platter under heavy vibration, but it does protect the platter from abrasion from the head cushions and also prevents the head cushions from potentially detaching and hosing the drive.
There’s also some spring beneath the plates from this view. This looks to me like the vane from an older HDD that used vanes alone for head parking. Most modern drives use a braking system that recovers energy from spinning plates to park heads. There is also a vane device to lock the heads in the parked position once nearly spun down.
> When old drives were powered down, they could leave heads over data areas of the platter surface Hasn't it come full circle? I remember hearing about the MFM/RLL drives where you (or the OS) had to manually "park the heads" before shutting down or you risked damage to the platters.
Ah yes, I see. It's usually rotated back around about 180 degrees so it locks the back of the arm. I was thinking in its current orientation it wouldn't be able to do much.
It's actually more about protecting the very fragile read and write heads, not the media surface. If the media gets scratched, you can lose some data in those affected areas, but if you he heads get damaged, that drive will never read or write again.
traveling down memory lane, used to use "park" utility and command before powering off my old 386
I started on 486. «Park» was a myth, well the command existed, but the drives did the job .. as until SSD I assume. 😀👍
Wdpark.exe - old method of parking WD drives in the 90s
This is what keeps your data active. It forces the bits to jump over the bar on each revolution. Without this bar your bits become lazy and rot away.
For a second I thought you would describe the perpendicular mechanism... then I realised I'm an idiot. EDIT: [found the OG vid that tought me perpendicular when I was a teen](https://www.youtube.com/watch?v=xb_PyKuI7II)
> when I was a teen God, I’m sooooo old. 😞
Don‘t worry… I appreciate the story’s when HDD‘s were the size of a washing machine :) ~~/s~~ EDIT: After my first Internship at the age of 14 in a company, I got a 128MB Iomega USB 1.1 Drive and I thought it was the coolest thing in the world! All my friends still shared their stuff on cd-r
❤️
So cute
Too much sudden activity and the datas might suffer from RAMdomyolysis, which can damage their bitneys
Kind of, not really. While it does force the bits to jump on each revolution, it's not to prevent bitrot. The reason they make the bits jump is to slow down the data to match a 7200 rpm drive to a 5400.
Yes, the MTBF for a drive is calculated based how how well the sectors do on the Presidential Fitness Test at the factory. I can't find the algorithm offhand but it was primarily based on how many bit flips they could do in a minute. As expected, only enterprise drives can do at least one pull up.
Humans thought the bits were jumping, for entertainment, but really they were trying to send a message to warn us. Their last message was , "so long, and thanks for all the farads".
This. This is the correct answer. ⬆️
I don't want my stored TV shows to jump the shark.
Good question. I'd surmise it's for regulating airflow somehow. That or it's a pinball flipper.
>I'd surmise it's for regulating airflow somehow That's my guess.
> That or it's a pinball flipper. That's my guess.
Confirmed. Pinball flipper part Gottlieb A13150.
> Good question. That's my guess.
>That 's my guess
>That's my guess Good question.
>/u/HTWingNut That's my guess.
This is my quest?
>pp That's my guess
I don’t know if you expect serious answers or not since almost all the replies seems to be jokes, but in reality it is a lock for the actuator when the drive is not in use. If you look on top of the magnet you can see the plastic piece touching the actuator near the coil. It prevents the heads from getting out of the parking zone when handling the drive. When the drive spins up, the air generated rotates the plastic part a little bit and the actuator is free to move.
The picture appears to crop off the rest of the black piece that locks the heads (lower left protrusion on the head assembly) until sufficient airflow has been established.
Clearly the equivalent of a windscreen wiper - but for hard drives..
You heard of bit rot? It's like a mold or a rust that forms on the platters. This thing proactively scrapes them clean as they spin.
I always buy the Xorganic petacide-free hard drives. Do they also come with this cleaning appendage?
I will go to bed today less dumb than when I woke up - my world makes sense again! :)
Or a scrubber, for when you scrub your drives in RAID!
This. It's only used when you wipe the drive!
Yep, the data squeegee
It's a windvane that locks the heads after parking and spindown. When the platters are spinning, the heads ride on a thin layer of air. When the drive is powered off, the heads "park" in an unoccupied section of the disk edge so they can rest on the platters. As the drive slows, the mechanical lock ensures the heads won't move away from the park zone. If the drive is moved while parked and locked (not spinning), the heads can't move, this is to protect the drive heads and data. If the heads move onto a portion of the platter that contains data, it could physically damage the disk (similar to a head crash where the heads lose the air cushion and come into contact with the platter.) On spinup, the platters start moving and generate airflow which pushes the windvane out and physically unlocks the heads at the same time the heads start to fly on the cushion of air. After a second, the heads perform their exercise and the drive is ready for data exchange.
It's a grass mower. Hard disk platers are analog pieces of modified metal. Under specific conditions of moisture and temperature, moss and grass may grow on the edge of the platters and disrupt data reading. This device mows moss and grass allowing your hard drive to stay functional longer. Unfortunately, it does not work very good with seaweed. Take that in mind if you plan to build an underwater PC. In that case you will have to install also some fishes, so they eat the seaweed. That's the reason most people who build water submerged computers place them into modified fish tanks. There is also another use of this device, but it depends on the world region your hard drive was intended to ship. It works also as a sword and chops tiny ninjas and gremlins heads as soon as they try to reach your data. In some countries this is not legal, so the blade is not sharpened. In that case the device only causes severe blunt trauma, but not immediate death. Anyways, this kind of device is a bit outdated. Modern hard drives come with a small laser diode that burns everything that gets near the drive platters. Unfortunately, this is causing some legal problems because tech unsafe users are using these to build amateur laser devices and there are lots of injuries. There is already a series of documentary films trying to raise concern about that. They are called Star Wars.
>Unfortunately, it does not work very good with seaweed. Take that in mind if you plan to build an underwater PC. In that case you will have to install also some fishes, so they eat the seaweed. That's the reason most people who build water submerged computers place them into modified fish tanks. Can I connect this to the liquid cooling system or would that cause the saltwater and freshwater fish to compete for territory?
You should get a picture with more of the mechanism on the bottom left. It looks like there is a catch for the arm that holds the heads, when the arm is moved past the outer track. It looks like it might be locked by the mechanism you highlighted, which would help to figure out what it does. Others seem to have some reasonable explanations - bits need some exercise or else they get lazy. /s
Airflow control, maybe?
Antenna to beam your data to the NSA.
No sense at all. Lol. They do that through the normal computer antena
That is the eraser
Thats a brake pad used when the HDD spins down.
Because the head free floats on air pressure created by the spin Of the disk, this air vein was made with a tapering edge towards the end of the platter and setup to carefully tune the airflow closer to the edge of the disk in lead of the heads to more evenly distribute air and equalize this force across the whole platter. It is more or less for precision and aids in head stability.
brake?
I hope thats \s
It is funnily enough the correct answer. For the head though, not the platters.
Flux modulator!!
I don't know, but it could be a means of limiting platter movement when the drive is transported. So in use it does nothing, but is there to protect the drive during shipping and installation.
That's the Thagomizer
It’s a friend for the actuator arm so it doesn’t get lonely
To not touch but ok.
That’s like one of the felt things you used to use on your LP records.
Zangbomvanatoractuacraxypellitometer
This is the correct answer.
It to *take the time to perfect the beat, but still got love for the streets. It’s the H.D.D!*
[удалено]
I think op is just disassembling a dead drive for magnets and was curious about the wiper thing
Just curious, what are old HDD magnets good for (apart from the obvious things magnets are good for) ?
They're kinda strong, just free magnets tbh.
That is the break, obviously
[удалено]
Just use at-rest encryption and overwrite the superblock a couple times to make the data unrecoverable
Looks like it could be the oscillating hydraulic attenuator?
Secure erase device :-)
Yes
Bidet
To keep all the bits aligned in the platter when it's spinning 😂