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HDD grinder with speed control

Surely, most people in the bins are idle old hard drives. From it you can make the necessary and useful thing for sharpening knives, scalpels and other items - a miniature grinding machine with a wheel speed control.

Will need


  • An old hard drive, even if it doesn’t spin, or without a board at all.


  • Sandpaper.
  • A pair of terminals for connecting the power supply.

You will also need wires, cambric for insulation and a few more little things.
Three main components are:
Hard drive in any condition. The engine in it is difficult to burn, so it is 100% suitable. And the board with the control driver will be purchased from us.
HDD grinder with speed control

The motor in the HDD is three-phase, brushless and very powerful. It will not work just like that from direct current, and to start it you will need a controller or driver for controlling a three-phase motor.
HDD grinder with speed control

To control the controller you need a speed controller, it looks like this:
HDD grinder with speed control

Assembling a grinding machine from a hard drive


So, open the hard drive. Here you have a problem - you will need specialized screwdrivers, since the bolts and screws are non-standard there. I advise you not to suffer and buy, or rent, a set with such screwdrivers.
HDD grinder with speed control

In general, we untwist everything: from above and from below, since nothing but an installed motor is needed.
HDD grinder with speed control

We remove the board, leaving only the connection contacts to the motor. Now look: motors in hard drives can have either three outputs or four.
HDD grinder with speed control

All envy on the method of turning on the windings. Somewhere they are turned on according to the "star" scheme, and somewhere according to the "triangle" scheme. Both options are suitable for us.
HDD grinder with speed control

Except that for a three-pin HDD, everything is clear with the phases - “ABC”, and for a four-pin HDD, you will have to look for the phases using a tester. We do not need the middle or common wire - it will not be involved.
HDD grinder with speed control

We connect the wires to the engine from the controller, isolate and fix with a metal jumper (you can cut it from a can).
HDD grinder with speed control

With the same jumper, we fix the controller itself from the side of the rotating disk.
HDD grinder with speed control

To cut a circle from sandpaper, remove the disk itself from the HDD motor. Attach it to sandpaper, draw a pencil around the back and cut with ordinary scissors.
It's time to stick the cut circle on a metal disk. It is all glued to double-sided tape. Your circle will not go anywhere, and it will be easy to change it when worn.
HDD grinder with speed control

Screw the disk.
HDD grinder with speed control

From the cover we make a protective casing for the controller. We cut out a semicircle with a dremel.
HDD grinder with speed control

And from a piece of tin we make a protective casing so that wear products do not fly to the controller.
The tin strip is soldered with a soldering iron to the hard drive cover.
HDD grinder with speed control

We collect everything. We connect the speed controller. Connection is made using a pin connector. These two modules are specially created for each other and are actively used in modeling.
HDD grinder with speed control

We connect 12 V power. Using the knob, we adjust the speed of the disk. Everything should work without configuration.
HDD grinder with speed control

Using a PWM controller, the speed is regulated very smoothly and within wide limits.
Now you can sharpen at least metal, at least plastic. Such a useful design is sure to find application in your home.
Thanks for your attention!

Watch the video of the grinding machine



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Comments (7)
  1. Vasya
    #1 Vasya Guests May 10, 2018 17:07
    1
    And all this despite the fact that the computer's power supply delivers a constant voltage of 5 and 10 volts to the disk ... It's good to hang noodles!
  2. Sasha
    #2 Sasha Guests May 26, 2018 07:49
    3
    Vasya you ... there is a 12V power supply, and the controller in the drive converts it into a three-phase voltage ... Read the materiel, you will be smarter!
  3. Dronsf
    #3 Dronsf Visitors January 8, 2019 3:59 p.m.
    0
    How much power do you need? I have 1A and the disk does not rotate, but it twitches barely
    1. Dronsf
      #4 Dronsf Visitors January 8, 2019 4:05 p.m.
      0
      If you help with your hand, it accelerates.
    2. Dronsf
      #5 Dronsf Visitors January 8, 2019 16:27
      0
      There is a 5v 450mA and 12V 215mA sticker on the hard drive case.
    3. Dronsf
      #6 Dronsf Visitors January 8, 2019 10:42 p.m.
      0
      I took another disk with the parameters 5 / 12V 700 / 800mA. It worked as it should.
  4. Guest Andrey
    #7 Guest Andrey Guests May 1, 2019 09:22
    0
    Why a garden? no need to throw out the insides, it starts fine. He pulled out the magnets, bent his head into the "pocket" that would not interfere, and everything starts fine from a regular PSU from a computer. Speed ​​control, well, if anyone needs it, you can put it. Although why is he on the emery, but in fact it is emery. It is possible to burn metal on a factory emery, it would be a wish).

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