Introduction: DIY Grinding Machine by HDD(hard Drive)

Hello! This is my first Instructable, and English isn't my first language(I'm from Taiwan(R.O.C)!!!). So please give me some comments to tell me how to make it better. Thanks!!!

The progress is pretty simple, but the product is really amazing.

Material: HDD, sand paper(roughness depands on what kinds of grinding you want), double-side tape

Step 1: Disassemble the HDD

Picture of Disassemble the HDD

You have to take the read/write head, magnet off. What's left is the case, major motor, disk, control circuit .

Step 2: Placing the Sand Paper

Picture of Placing the Sand Paper

Cut the sand paper into the matching size of the disk(mine is 3.7"), and one on top.

Then stick it on the disk by double-side tape

***The tape must be put balanced well, or when it turns in the high speed, the motor may be damaged or the sand paper may fly out***

Step 3: Protecting Shield (Optional)

Picture of Protecting Shield (Optional)

The shield is used to protect things from flying out and hit you.

I made it by two aluminium sheet from two soda cans.

Step 4: Power It

Picture of Power It

You can simply power it by the PSU from computer.Or make a control circuit by your own.(There are many good ones in Instructables)


Thank you for your reading!


TechnicalKid (author)2015-11-15

hey thats cool, but when i tried to build it i had to let half of the litle arm inside the case, becuse if i wantetd tu unplug it the HDD stoped turning all 10 seconds can someone help me ?

Neowizard (author)TechnicalKid2015-11-23

You can try to trick the controller by shorting some of the RW head connectors, but that only works in rare cases (and can burn up the controller in other cases).

You can also try what I eventually did, and work above the RW head (so you don't need to touch it), by adding an extra platter on top of the existing assembly. In larger disks there's easily enough room for it on the spindle.

Go JunN (author)Neowizard2016-05-20

I have a dead TOSHIBA HDD 170 GB with two platters, the problems is it has two transducers (R/W) making it impossible to put another extra platter, can you tell more about the details about tricking the controller? Thank you in advance

Neowizard made it! (author)2015-11-23

When I made it, I had the same problem as most people. Once I removed the read/write head, the disk-motor would stop after a few seconds (seems like the controller notices there's no response from the head, and stops the HDD). I tried several solutions, (burnt a couple of HDDs in the process), but the only solution that worked for me was to simply not remove the head at all.

What I did was to add another HDD platter on top of the exiting ones and put the sand paper on that extra platter, and so the RW-head isn't in the way. Now it works great

kaddigart (author)2015-11-14

It's been a while since you posted this but I'll give it a shot anyway-

I'm not disputing that the 3.5 inch HDDs don't need/use the 12v rail, reading your other comments you obviously know your tech. My question though, is if it is pretty much there just to be backward compatible or to adhere to the Molex standard, why are all (at least all I know of) external 3.5" HDD enclosures powered by 12v wall warts? Couldn't they theoretically run from a 5v PSU like the their 2.5" cousins?

mskogly (author)2015-09-04

Didn't understand the 12v wall wart hack mentioned in the comments. Mine just twitches, no constant rotation.

amiir made it! (author)2015-06-08

Here is mine :D

its very good.

better use 7200rpm HDD like WesternDigital Black series

AlvinS4 (author)2015-05-04

Congratulations, I really like the idea that you came out with, I have a question doesn't the double sided tape come
Off due to heat generated by sanding or grindin?

thomasya (author)AlvinS42015-05-04

I've never thing it this problem. Although it may happen, the chance might be low since it is hard for the heat to transmit through sand paper and it's not so easy for the whole double sided tape to fail. However, to make it safer,I think it should be cooled down after using.

Thanks for your good question!

Cyberchipz (author)thomasya2015-05-16

I think because the tape is evenly distributed and forces are basically in equilibrium because of speed and balanced, the tape probably stays put except under extreme conditions where the drive would stall or nearly so.

EtienneS (author)2015-05-10

Brilliant, brilliant brilliant. I just inherited about 30 junked HD's, and this is GREAT!!!!!!! Going to put one together tonight.

matjaz.zikovsek made it! (author)2015-04-26

Great Idea. I made it! My variant of HDD also have some Overload protection (when I press to much on grinding disc, It power off..)

good and safer design than mine, but i think it limits it's potentials/use because the "shield" won't allow you to sharpen knives....

we can lessen the effort of unplugging/re-plugging our molex by adding a normally closed switch, so when it stops we just have to tap the switch and continue....

spark master (author)wazalac182015-04-26

If you sharpen a hardened properly annealed blade at over 90 rpms, you just may destroy the temper and then need to do a lot more work to fix it, like getting it cherry red hot then quenching then annealing at about 400 degrees.

For that use, get an old record player, or a (same exact concept I made mine years ago), and I can change grits real easy glue different ones to cardboard platters that fit on the spindle. Or make a plater on a spindle and power with an old hand mixer.

For sharpening knives, slow is better. 70-90 rpms, I was told, is best. (unless you have specialty steel blades that can take the rpm's and the heat, none of my carving knives will do that)

wazalac18 (author)spark master2015-05-04

you are right if this hdd grinder can deliver even half the torque of a regular grinder, but if you can stop it with just poking a finger (on the smooth side of the platter) , then how can it produce such heat with that kind of friction ?

Im replying with my phone and cannot upload pictures directly so here's the link.....

I use hdd grinder on that knife but there is no sign of heat damage on the blade.

..In first it is not mean for sharpening, but for pollishing.. So, I upgrade the housing for sharpening knives or scissors.. My butcher told Me, the best angle for sharpening knives is 22,5 degree and I made neckline in housing of HDD and glue some fine sand_paper on circumference of 3_disc in HDD..

I just improvisation.. :)

thomasya (author)matjaz.zikovsek2015-04-27

Wow! How do you cut the plate above the HDD?

JeranF (author)thomasya2015-04-27

Probably he used a metal cutting / jigsaw.bandsaw

Very good Matjaz!!! I like your version better!!!

stuart.jones.75470316 (author)2015-05-04

fantastic Idea for repurposing of old computer!

muy (author)2015-04-27

i had make with seagate hdd, but power goes down.. the disc spinning only 30 second.. please tell me why..?

ridalyn (author)muy2015-04-30

I would take a molex plug (the power plug for the hard drive) disconnect it from the power supply unit (or get one from a parts store like Radio Shack). Then snip the red wire and the black wire closest to the red as close to the plug as possible. Then take a 12 volt power supply (wall wart) and solder the yellow wire to the positive lead on the wall wart and solder the black to the negative lead. Be sure to tape or shrink wrap your splices to avoid grounding. This should give you constant power to the drive without having a clunky power box taking up valuable bench space.

lhj734017 (author)ridalyn2015-04-30

or make something like this and no more wasted work space. I was even able to solder using this power supply

jeffwizardcox (author)muy2015-04-29

if you are using a computer pwr supply as a stand alone source, they will auto shutdown unless some of the other wires are grounded

damyar (author)2015-04-30

Cool .
Bat this hdd in not powerfull well enough to work good.

CraigRJess (author)2015-04-30

Add stick-on velcro to the disk.

Then, go to automotive body shop supply store and buy the 3, 4, or 6" velcro backed sanding disks and attach to the disk. They're meant for quickly adding/removing from the sanders.

They come in all the grits - 60 up to 5000 grit.

alan joyce (author)2015-04-30

Great idea which I wish I had seen yesterday, took mine to the dump.! I did manage to salvage most of the metal and striped the heat reducers (not sure what their name is ) but they have fins on . My wife now uses them for lamp working glass, gives a nice pattern .

jeffwizardcox (author)2015-04-29

On your English

don't say, and one on don't need to say it.

you are confusing our use of by and with...........I made it with two Al sheetS also,

you can simply pwr it with the PSU....

My wife is from Tiapai where I lived for 5 years working as an engineer on the construction of the MRT systems. We met at Washington State University and I would not marry her until I lived in her country for a long time. We have had a very happy and fun marriage both in Washington and California.

morsed2 (author)2015-04-28

Brilliant idea, I am going to try it out as soon as I can.

As for your english, Sir, it is excellent.

Groaker (author)2015-04-26


This is similar to a device on the market that is used for sharpening tools.

If you have a couple of these drives, perhaps leaving the platter on one, and using a fine grit such as diamond, carbide or other agent mixed with olive oil to adhere it to the platter would produce an extremely sharp edge on a tool.

This is also not dissimilar to a faceting machine, and gems could be cut.

Note that diamond grit is relatively inexpensive in the grades and quantities used.

As soon as you powered it up the oil / grit would fly off due to centrifugal force - you MAY be able to glue epoxy resin / grit mix onto it, but the sanding action will create heat that will make the glue soften again.

You can buy lapping sheets with grits up to wait for it.... 500,000 yes 1/2 a million - but even 5,000 will give you a razor sharp edge (I know, that's how I sharpen my hand planes).

You could buy a bunch of "dead" HDD's for pennies and set up a row with differing grits and a toolrest.

People have been faceting stones with this combination for millennia. Myself included. I will agree that the speed should be cut, but that is likely not a big deal. Of course another technique would be to make Al or Cu disks and use pressure rollers to force impregnation of the grit into the lap. Then only water need be used as a lubricant, coolant, and swarf remover. I use both metal and fabric based laps for sharpening wood and metal working tools. But fabric based grits will not have the tolerances necessary for facetiing gems.

MeasureTwice (author)Groaker2015-04-27

I was in the industrial diamond industry for 28 years... sold diamond tools and polishing compounds to IBM for machining heat sinks and silica memory platens. I believe the HDD disks are a silica based composite... they can shatter like glass if allowed to run up to high. Also, by putting side pressure on it, it may start to oscillate and cause this. I personally would change the disk out for a steel center cut-off blade core or machine down an old saw blade and use it's center. It would need to be well balanced also, especially at higher speeds.

You are half right - the 2.5 LAPTOP HDD's are glass composites - but the larger HDD's for towers are 96% aluminiumn 4% magnesium core with some outer coatings only microns thick to make it work.

Good you brought that up point though.

spark master (author)Groaker2015-04-26

3,000 rpms will burn the steel, unless you can cool it way way down.

thomasya (author)spark master2015-04-27

Yeah, when I'm doing the experience of the ring of the coke can, I can feel the heat from the friction.

bowen93 (author)2015-04-27

i powered mine with a simple 12v wall adapter, i cut the molex connector off a dead power supply i have enough of them and soldered the wired to the 12v wall adapter, i rigged a simple switch into the 12v side of the lead so i can turn it off and on. another one i did before i have spare cheap fan controllers, they run 12v. again put the molex connector to that and connect another molex to fan cable. that way you also have speed control as well as an off on switch

I8mAll (author)2015-04-27

Well done that is a nice way to use up parts that are redundant. I like to keep the magnets as they are very strong and useful for other projects.

thomasya (author)I8mAll2015-04-27

Yeah, I'm also thinking where to use my magnets, but the problem is I don't know how to separate it from the metal holding it.

glamonica (author)thomasya2015-04-27

I use a dull chisel. clamp the magnet and metal in a vice. Put the sharp(dull) side against the metal holding the magnet and give a good firm thwack with a mallet.

SporeC (author)2015-04-27

So that's the spinning sound i hear in my laptop. :|

SporeC (author)2015-04-27


zappenfusen (author)2015-04-26

How would you power it using a wall wart of the correct voltage and current? Which wires do what?



robbied (author)zappenfusen2015-04-26

You need both 12V and 5V lines to run it.

zappenfusen (author)robbied2015-04-26

12v AC motor, 5v DC control?

robbied (author)zappenfusen2015-04-26

Yes, the output from the drive circuit is 12V AC, but the input from the power supply is both 12V and 5V DC, regulated. Yellow is 12V, red is 5V

zappenfusen (author)robbied2015-04-27

Thanks for the info. I've an abundance of magnets but could never get any movement except fits and jerks out of the ones I've destroyed. Never crossed my mind they're 3 phase electronic controlled.


richardsan (author)2015-04-26

is there any concern about what material the platters are made from?
if they are a silica/ very careful about using them in an application such as this one.

thomasya (author)richardsan2015-04-27

Mine is a piece of stanless steel, I think.

MoTinkerGNome (author)thomasya2015-04-27

The platters are either aluminum (common) or ceramic(not as common), with platinum alloy plating

About This Instructable




Bio: A high school students from Taiwan!!!
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