What is the rotational velocity of hard disk actuator arm?

[rkatcosmos]

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There is a lot of material discussing the rotational speed of the magnetic disk in HDD but not about the rotational speed of actuator arm.

What are the typical actuation speeds of the actuator in HDD?

This information will be used in the design of a fast shutter system made by salvaging the HDDD actuator arm.

 

[jim hardy]

Check the wikipedia article on "Seek Time" which is the time to find a track.
https://en.wikipedia.org/wiki/Hard_disk_drive_performance_characteristics

It says 10 milliseconds is typical , but that's statistical not worst case because the head seldom has to move all the way across the disk.

 

[Tom.G]

From reference 9 in hte article you referenced: http://pcguide.com/ref/hdd/perf/perf/spec/posSeek-c.html

Full Stroke: This number is the amount of time to seek the entire width of the disk, from the innermost track to the outermost. This is of course the largest number, typically being in the 15 to 20 ms range. In some ways, combining this number with the average seek time represents the way the drive will behave when it is close to being full.

A look at the specs of a random drive on the Western Digital site showed a diagnostic report of 21ms full stroke.

 

[Merlin3189]

If that is the time to move from stationary at the inner track to stationary at the outer track, presumably the peak speed will be significantly larger than the average speed you'd get from this.
Though, if it is to be used as a shutter, you may want the time rather than the speed.
And in that case, you may not need the deceleration phase. Just bring it to a hard stop mechanically.
Presumably the coil can run potentially almost continually during heavy disc activity, so perhaps you could significantly overdrive it for occasional snaps, unless you want it for movies.

 

[Tom.G]

If case you haven't seen it yet: https://en.wikipedia.org/wiki/Focal-plane_shutter

Also:
https://www.google.com/search?source=hp&q=focal+plane+shutter+animation&oq=focal+plane+shutter

https://www.google.com/search?source=hp&q=leaf+shutter&oq=leaf+shutter

For a really fast shutter, consider an electro-optic approach; such as a Pockels cell.

 

[davenn]

If case you haven't seen it yet: https://en.wikipedia.org/wiki/Focal-plane_shutter

Also:
https://www.google.com/search?source=hp&q=focal+plane+shutter+animation&oq=focal+plane+shutter

https://www.google.com/search?source=hp&q=leaf+shutter&oq=leaf+shutter

For a really fast shutter, consider an electro-optic approach; such as a Pockels cell.

did you mean to post this somewhere else ??
it's all about camera shutters and nothing to do with HDD'sD

 

[Tom.G]

did you mean to post this somewhere else ??

Thanks for the 'Heads Up' but, no, it's in the intended place. See post #1

This information will be used in the design of a fast shutter system made by salvaging the HDDD actuator arm.

 

[davenn]

Thanks for the 'Heads Up' but, no, it's in the intended place. See post #1

ohhhh my bad ... missed the shutter bit in post #1

 

[davenn]

as an aside ...
I abhor those "rolling shutters" used on cameras these days as shown in your first link
scroll down to the lightning photo and the banded light and dark

All modern CMOS sensor cameras use the rolling shutter system and when doing video of lightning, it totally destroys the image as you can see and often even wore than that.

I am still using a 2007 yr Fuji S9500 CCD sensor camera that uses the "global shutter" system
and the lightning strike doesn't get chopped up

in video mode, the mechanical shutter stays open and the rolling shutter system just scrolls / collects a horizontal band of signal from the sensor

in the CCD sensor cameras ( video mode), even the one I bought in 2012, the global shutter system just switches of signal collection from the full sensor every 30 sec or whatever the frame rate is
As a result, the image doesn't get chopped upDave