Better Computing Through Velcro: Make Your Laptop A Dock For External HDD's

 by thread_soul
Featured
THE PROBLEM:

There's rarely a safe and convenient place to put a portable external hard drive when using a laptop in a mobile, non-desk situation.

Example:  You're working on your laptop and want to back up some files or work on some media that you have stored on an external drive.  You pull it out of your bag and look around.  If you're on a plane or train, at a coffee shop with a teensy-tiny bistro table, or lounging outside on a patio, you'll quickly realize there's no convenient place to put the external drive and be assured that while in operation it will be safe from liquid spills, getting whacked, or falling off of your lap or miniature workspace.

THE SOLUTION:

Adhesive-backed velcro strips.

THE CATCH?

A Geek Factor of  6/10  -  This isn't for the fashion-conscious or those wishing to keep their laptop un-customized.

WHAT YOU NEED TO DO THIS:

# 15 minutes

#  Velco or other brand hook-and-loop adhesive-backed fastener strips.  (comes in rolls or pre-cut lengths)

#  Paper towel or clean cloth.

# Scissors (with which to cut the velcro to size)

# Pencil  (to mark and measure the velcro)

#  Isopropyl Rubbing Alcohol or other grease-removing, residue-free cleaning agent.

#  Portable External Hard Drive  (or WiFi / wireless dongle, CD-Rom, tethered smartphone, etc)

#  Laptop

New Material Cost:  Under $10

 
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Step 1: Velcro Engineering (Or, Is My Hard Drive Safe?)

VELCRO SPECS.png
The first and most immediate concern:  is velcro strong and reliable enough to hold an external drive and weather normal movement from the laptop without the risk of it falling off?

Short Answer:  Yes.

The Long Answer:  Hook-and-loop products are rated by 3 important characteristics:  Pull-apart strength, shear strength, and cycle-life.  The products also come in two main grades:  consumer-grade and "industrial strength" or "mil-spec" (i.e. military spec, or other governing-body specified and regulated).

Pull-apart strength measures how much force per unit area of velcro it takes to separate two pieces straight apart from each other.  This is usually anywhere from 0.8 - 2 psi for both versions.

Shear strength relates to how much it takes to "slide" the opposing velcro pieces apart.  It typically varies from 6 - 10 psi for most.

Cycle-life determines how many times the pull-apart / stick-back-together operation can be performed before the holding strength of the velcro degrades to 50% of its initial value.

This is where there is the biggest distinction between the two types.  Consumer-grade velcro that can be purchased from any number of general hardware and goods retailers usually has a cycle-life of a few hundred.  Mil-spec has a cycle-life ranging into the several thousands.

Some quick numbers:    

Discussed further in Steps 3 and 6, I chose to have two strips of velco on the hard-drive intersect perpendicularly with two strips on the laptop.

Thus, there are 4 points of contact between the hard-drive body and laptop, and given 5/8" wide velcro strips, the total area of velcro contact is 1.56 in^2.   Taking the lowest strength values (0.8 psi pull-apart, and 6 psi shear), this amount of velcro is therefore capable of withstanding 1.25 lbs of pull-apart force, and 9.3 lbs in the vertical, shear direction.

Most 2.5" portable external hard drives weight about 0.25 lb.  This means that in the pull-apart direction, the HDD could withstand 5 G's of acceleration before pulling off, and up to 37 G's before shearing off in the vertical direction.

Likely, for your HDD and laptop to experience those accelerations, it would only occur when they slammed on the floor after having been dropped from a height of several feet.  Normal use and fidgeting shouldn't be nearly enough to separate them.

The Usual Disclaimer:

Use your common sense when approaching this project.  I've calculated and real-world tested using the above specs; they're solid.  If in your own application of this 'ible you deviate significantly from the given advice by using too little velcro or attempt to attach an abnormally heavy hard-drive or peripheral, you are responsible for what may come of it.
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ahead says: Mar 6, 2010. 11:45 AM
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bsharding1982 in reply to aheadApr 14, 2011. 7:04 PM
That is funny, you could use it as a mobile "corkboard" too :)
thread_soul (author) in reply to aheadMar 7, 2010. 3:01 PM
 Nice!  The indoor/outdoor carpet was a very clever idea.  So you've not had any problems with the monitor getting too hot?  That's great if so, very functional for anyone who needs additional peripherals to be readily accessible.
ahead in reply to thread_soulMar 8, 2010. 8:17 AM
No.
The only heat issue is from the usb devices: EHD, data card and usb hub. Not the monitor.
The hook-side skin adhesive underneath the devices may slightly pull-away when hot.  
Especially if the device surface area is small and "always-on". 

Thanks.
m4s says: Jan 18, 2011. 10:32 AM
very neat concept indeed
thank you for sharing the details

www.sleektablets.com
junits15 says: Feb 16, 2010. 5:15 AM

This is a neat concept, however the drives can be less stable while mounted to the screen, now, I do understand that you calculated that this would be safe.  However mounting the drives like that could shorten their life cycle.  I myself use an SSD in my laptop, because I'm a little parinoid and, more importantly, because I got it for free.  Anywho this is still a good idea.

***

thread_soul (author) in reply to junits15Feb 17, 2010. 1:06 PM
Thanks for your feedback!  If you wish, could you elaborate upon your concerns?

"the drives can be less stable while mounted to the screen."

"However, mounting the drives like that could shorten their life cycle."

I ask because short of having some specific physics/specs to respond to, I can only reply that there seems to be a general amount of misapprehension in computing culture at large regarding the ruggedness of modern mobile HDD  - probably a perception carryover from failed HDD of yore that had much older, less robust actuator and head-parking designs.

Current 2.5" HDD are spec'd to operate both in vertical and horizontal orientations and the vast majority of them have shock and vibration ratings that are pretty difficult to exceed in any general situation, including any accelerations one might encounter in this configuration from adjusting the laptop screen.  In many instances dropping them isn't even enough to cause failure, but I wouldn't recommend testing that  :)

Most of the safety recommendations I proffer in this Instructable are taking a conservative stance in most respects, and in truth one could probably ignore them and still be relatively risk-free, but I'd prefer that things have an additional built-in factor of safety. Of course, it in the end it will always come down to one's own comfort level as far as choosing whether to do this project or not, but I can assure that at least according to the numbers and physics involved there's not any more risk here (and quite possibly, there's less) in comparison to traditional use as an external HDD or within a laptop.  Many thanks for commenting!
hintss in reply to thread_soulAug 19, 2010. 8:28 PM
I tested it. it still works
junits15 in reply to thread_soulFeb 21, 2010. 3:17 PM

I was referring to older HDDs, I also wasnt aware that newer mobile HDDs were as robust.  by my first statement i meant, a weaker scrren might not be able to support the extra weight.  and the seccond statement...that was answered by my first sentence.

crice6 says: Feb 28, 2010. 7:10 PM
or just go to www.dropbox.com and skip the EHD
thread_soul (author) in reply to crice6Mar 2, 2010. 9:13 AM
cloud-based backup is extremely limited in application, EHDs aren't.
MNSnowbird says: Feb 19, 2010. 7:46 AM

Great Idea.

To keep the hooks on the External Hard Drive from collecting lint and other foreign material when not in use cut 2 additional strips of loop material and put them on the E.H.D.
thread_soul (author) in reply to MNSnowbirdFeb 21, 2010. 12:18 AM
Good suggestion!
wout smeets says: Feb 19, 2010. 4:38 AM
 use an  usb splitter
HAL 9000 says: Feb 17, 2010. 12:12 PM
 I did this with my MSI Wind as soon as I got an external drive, its so handy. I didnt do the double parallel velcro strips, just one strip on the laptop and one on the HDD. It's really only big enough for the one HDD, maybe when i get a bigger surface I'll try this out. 
pravardhan says: Feb 15, 2010. 6:26 AM
If you know what is G-Force, then you would not have done this.

If the Hard Disk (Moving Parts type not SSD) is dropped with the Gravity, then the Head Pre-Amplifier IC will not work and the HDD will do a clicking noise and the HDD will not even detect.

RISK: DO NOT ATTEMPT TO DO THIS INSTRUCTABLE.
Phoghat in reply to pravardhanFeb 16, 2010. 3:08 PM
I have seen Extenal drives with shock ratings and don't think you've done your research too well.
I just bought a drive and enclosure for newEgg and Both have shock ratings.
I bought the drive to clone my laptop and upgrade it. I will take my old one and try this.
As for dollar store hook and loop, why not splurge a little and buy the 3M stuff used for sticking you pass to the windshield. I do not think it will let go under any circumstance.
mhkabir in reply to PhoghatFeb 17, 2010. 7:40 AM
 Me too. I got a Seagate  Barracuda and spilled coffee on it! Sh*t and dropped it from my lap. Got to say the ruggedness of the barracuda is huge.
Phoghat in reply to mhkabirFeb 17, 2010. 10:24 AM
I have  seagate also because I did my research
thread_soul (author) in reply to pravardhanFeb 15, 2010. 6:48 PM
Thank you for the comment, perhaps there is a language misunderstanding here?

In Step One I calculated the strength of the velcro.  It is sufficient to hold the HDD up to 5 G-Forces.  There is very little risk in completing this project.  Instead, it may actually help people to prevent dropping their HDD.
tjfoth says: Feb 15, 2010. 6:02 AM
I've attached a external hard drive to my Macbook Pro as well.  One small difference is that I have a plastic cover from Speck on my Mac which I've attached the Velcro and hard drive to. Using the Speck cover spreads the force of attaching and removing the drive over the plastic cover. In addition, as the author noted, my Velcro is near the edge and near the hinge.

The reason I do this to the Macbook Pro in question is because this is my work computer.  When I want it to be "my" computer, I attach the external hard drive and boot from that.  I have a script that unmounts the internal hard drive... therefore keeping my work environment separate from my home environment.

I attach and remove the hard drive EVERY day and have done so for over two years with no problems.
alpha1040 says: Feb 12, 2010. 10:02 AM
i hate to point this out and while it is a very good idea in theory and would work really well for a solid object like a desk this is a very bad idea in reality. Behind the lcd screen there is a metal sheet that the hinges are attached to. By putting pressure on the screen you will wear through the back plate a LOT faster. I do computer repair work as well as building systems for a living and iv seem this many times.
thread_soul (author) in reply to alpha1040Feb 12, 2010. 5:31 PM
Your feedback is certainly appreciated!  Though in this specific circumstance, I'm sorry, I feel I have to disagree with your conclusion.

To be frank, I've worked on and around laptops for more than 12 years.  I've never once encountered an issue related to complete wear-through of the grounding foil.  Busted hinges?  Plenty of them, though as an aside even that's become much less frequent these days.

Most laptops that I've seen the innards of within the past half-dozen years have either abandoned the "full sheet" grounding foil in lieu of smaller strips of edging foil, or have introduced foam pad points to inhibit the rubbing that you suggest.  These contemporary design features would alone be enough to prevent any velcro-related action from wearing through the foil.

Beyond that, however, prior to commenting you might not have had the chance to read that in step 6 of the instructable I recommend that the HDD is best placed close to the hinge and edge, thereby distributing any related forces directly to the case edging - and thus the screen mounting brackets rather than the back of the lcd panel.  My own tests on a couple of different laptops indicate that this essentially eliminates any flexing of the back panel casing, in contrast to if the HDD was placed in the weak center.  This conclusion, combined with the aforementioned design factors, makes it difficult for me to find it realistic that increased foil wear will result from this hack.  Many thanks for taking the time to comment!
RLDMICRO in reply to thread_soulFeb 14, 2010. 11:13 AM
I completely agree with your polite and well-thought-out rebuttal to Alpha1040's concern.   Let's be realistic:  Laptops don't live "forever"... not even close.

I too refurbish PCs and laptops. I run into broken hinges, coffee spilled into keyboards, cold solder joints, crashed hard drives, and dropped/broken laptop screens wayyy more often than the worn-thru backplanes Alpha1040 is warning us about... It may have been a risk in the past, but not in 2010.

What I *have* seen are damaged laptop USB ports, when a book (or some other heavy object) fell over onto a "thumb drive"/flash memory sticking straight out from the edge of the laptop. 

Instead of plugging USB "stick" peripherals directly into the laptop, I recommend users connect USB wireless peripherals via a very short (6") right-angle USB extension cable.  This substantially reduces the risk of damage to the laptop's USB port, and attaching the USB device to the back of the screen using your Velcro solution makes the installation nearly damage-proof.  

The question is:  Why haven't manufacturer's figured this out yet?   

Thanks for your great Instructable!

thread_soul (author) in reply to RLDMICROFeb 15, 2010. 1:57 AM
 Thanks!  That right-angle USB extension cord is a clever idea, it'd be perfect for more persistent dongles like wifi, mouse, or even for getting better reception with a 3G adapter like @zzzomb mentioned.  It think I just may have to try that out.

Also, it just made me realize this could be a useful solution for anyone tethering their smart phone as a modem.  That way, it wouldn't be so inconvenient to tether through USB, and battery life can be spared by not having to connect via bluetooth in order to be able place the phone somewhere convenient as well as with good reception.
inness in reply to RLDMICROFeb 14, 2010. 2:59 PM
That, my friend (and with such a brilliantly simple fix offered as a throwaway, I feel comfortable in calling you my friend), is a terrific idea, and removes the worry and anxiety I feel whenever I move my laptop with the wireless mouse drive attached. One does wonder why the manufacturers haven't thought of this. Were I a cynical man I would suspect either intentional disregard for the end user; or even more cynically, an intentional lack of implementation based on the 'disposable' theory of laptops so many manufacturers have seemingly promoted. Again, great idea!
RLDMICRO in reply to innessFeb 14, 2010. 3:21 PM
Ha!  I'm full of "throwaways".  You're not the first person to comment on it, but it's probably always gonna be that way.  The Inventing, Prototyping, Marketing required to make such thoughts anything more than throwaways is very unpleasant !  ... It takes all the "fun" out of the creative process.

It's actually gracious comments like yours that make it all worth while.  Thanks!

And, for what it's worth, I'm a big "Conspiracy" fan (even when the "conspiracy" can be traced directly to the level of the Human Genome...)

Point: => I think the laptop/USB designers just don't give a sh*t...  their firms are actually driven (and perhaps as it oughta be) by the Marketing Suits.
Recommend you start scoping out your next laptop... the mechanical weakness of the USB peripherals probably wont be fixed in my lifetime.
                                                                                                                   ;~)

Doom and Destruction in reply to RLDMICROFeb 28, 2011. 4:51 PM
my laptop has two USB ports on the back. it just so happens that they are right under were i put the external hard drive. so a book would hit the hard drive first.
DeusXMachina in reply to RLDMICROFeb 14, 2010. 12:09 PM
I've always wondered the same thing. It takes a 3rd grade handle on physics, simple machines, and levers to see that anything sufficiently long sticking into a receptacle puts tremendous torque on both internal and external components.

Unfortunately, even the right angle replacements are a little wide to provide sufficient safety. What they need is a plug roughly the size of Bluetooth adapter 'nubs' that has an immediate right-angle turn out of which the cable exits.
RLDMICRO in reply to DeusXMachinaFeb 14, 2010. 3:10 PM
Funny how the track of the discussion so easily departs from strict "electronics" and becomes "Industrial Design".   I always find that "human", practical side of these projects wayyy more interesting than the guts.

As for your comment re "3rd Grade Handle on Physics"....  I think you seriously undervalue that "handle" when you describe it so casually:
Sadly, I suspect that "handle" can't really be "taught".

As proof, I'll bet you were taking apart devices at a young age... playing at "Physics" long before you actually "learned" it in Physics 101. 

Either you've "got" it, or you don't, like a musician with Perfect Pitch.

That's just my 2 cents...
doctoral says: Feb 14, 2010. 6:32 PM
Just so you guys know. I live in los angeles and the 99 cents store has velcro straps, dots, squares etc.
thread_soul (author) in reply to doctoralFeb 15, 2010. 1:40 AM
 I didn't think about checking there, great suggestion!
debie says: Feb 14, 2010. 2:55 PM
 I did the same thing.I got tired of having my external hard drive fall on the floor every time I moved my laptop.  I have a plastic case for my mac, so I attached the velcro to that. It makes it so much easier to get around!
thread_soul (author) in reply to debieFeb 15, 2010. 1:34 AM
 Ouch, I hope your drive survived those falls!  Not had it happen to me, but the fear was enough to make it an irritation and spurred me to sort out something to do about it.
PatientZero says: Feb 14, 2010. 6:21 AM
A variation of the desk tidy solution:

I once used two lengths (1.20m ea) of the soft velcro siding underneath the rear of my desk and then used the hook siding in short parts for strapping cables to the underside of the desk.

An easily adjustable cable tidy. Also, because the "fuzzy" strip was about 5cm wide, I could stick my router under the desk too.


thread_soul (author) in reply to PatientZeroFeb 15, 2010. 1:32 AM
A clever idea for cable management, will have to try it!
JamesRPatrick says: Feb 14, 2010. 10:05 AM
Have you ever tried using the 3M strips that attach Speedpasses(or Fastoll or whatever) to windshields? I used four of them to mount a CB radio and that stayed on pretty well, not sure of the specs. I do know that it doesn't work well in hot climates, but at failing temperatures a laptop would probably be dead anyway.
thread_soul (author) in reply to JamesRPatrickFeb 15, 2010. 1:29 AM
 I've not, personally.  3M is the manufacturer of the brand name Velcro fasteners, so it would probably be safe to assume that those strips should have strength specs that are plenty sufficient, and the cycle life would probably be a few hundred cycles, but that's just a guess on my part.  An yeah, the temp should be ok, I'd bet attached to the windshield it would get much hotter than what would occur on the back of a laptop.
gundamyai says: Feb 14, 2010. 10:21 AM
good good ...
easy ... 
thank
zzzomb says: Feb 12, 2010. 1:15 AM
My mobile broadband 3g dongle was proving to be a hastle poking out the side of the laptop. Easily bumped. I tried a short usb extension cable to the dongle velcro'ed onto the rear of the screen like this. For a while it worked great, but then our Australian hot summer set in. It turns out that the ambient temperature combined with the heat generated from the device itself is enough to melt the self adhesive. This leaves the velcro in place, and the device sliding straight off like melted hot glue.

Solution? If you live in a hot climate, superglue should be fine to glue a velcro patch in place permanently. But instead, decided to superglue the actual usb extension cable itself, leaving the dongle poking out the top where reception works a little better and keeping it a bit cooler.
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