Tesla Turbine From Old Hard Drives and Minimal Tools




About: At heart an engineer, musician, polyglot, cook, computer programmer, wood worker, brewer and hacker.
Build a Tesla turbine from 2 old computer hard disk drives using basic hand tools and a pillar drill. No metal lathe or other expensive fabrication machinery is required and you only need some basic craft skills. It's crude, but this thing can scream!

Tesla Turbines promise up to 92% efficiency of converting air or fluid flow to rotational energy and its use can also be inverted for use as a pump with exceptionally high efficiency too. With compressed air becoming recognised as a feasible form of energy storage, we can see this device in everyday life soon as a source of locomotion. Factoring the simplicity, robustness and resillience to ingress of this design and you have something ideal for pumping heterogenous fluids like sewarage or fluids with suspended particulate. As a pump, this device has an important role to play in the developing world. More about it here: http://en.wikipedia.org/wiki/Tesla_turbine

Step 1: Tools That You Will Need

1. Torx set of screwdrivers to disassemble the hard drives and to build the rotor
2. Circle cutter - get this from you stationary shop for 1.99
3. Engineering Compass - optional, you can use the circle cutter to mark the workpieces
4. Sheet-metal drill bit and a 5 mm drill bit
5. Half-round file
6. Hole file
7. Craft glue or hot-melt glue
8. Epoxy glue to bond aluminium (that's aluminum to you lot in the US/Canada!)
9. Gaffa/Bodge/Duct/Electrical tape
10. Hacksaw with metal blade to cut aluminium (see proper pronounciation in item 8)
11. Pillar drill
12. Compressor to supply the air to drive the turbine. You can also use a drinking straw and blow really hard 'till your eyes pop out.
13. Some spare hard disk platters (chances are that you will have a couple of attempts to cut the right shape of slots in them)

Step 2: Materials That You Will Need

1. Two hard drives.
2. Erm... that's it.

Step 3: Disassemble the Hard Drives

You will most certainly need the Torx screwdrivers to this. Remember that there also screws under the label, sometimes just one, mostly two.

The magnets and the armature assembly needs to be removed. Often, the top magnet is not screwed on at all but held on using (you'll never guess!) its own magenetism. Strip the hard drive right down - you should have a between 2 to 4 disks per hard drive.

Step 4: Build the Casing

With the 2 hard drive cases, use the bhack saw to cut each one in two so that when the parts are joined together they form a circular casing in which the hard drive motor can be mounted.

Cut along the red lines indicated on the pictures and start by making the larger half first - that way, if you bollocks it up, you can use this bit for the smaller half and reattempt to make the larger half from the second hard drive.

Then assemble with two halves with epoxy glue, making sure that you can spin a disk platter inside the newly-formed circular enclosure without it touching the sides. Clamp it and let the epoxy glue cure.

While you about with the epoxy glue, fill any gaps on the side with it to prevent air leakage and to reduce turbulance.

Form an air nozzles into the circular enclosure where the air filter is and drill a 5mm hole where the air inlet is going to be (see last picture)

Step 5: The Back Plate

The back of the disk drive enclusure may be stepped and the drive motor will probably have a step in its shaft too. The solution is to glue a stationary back plate in the casing over the motor.

Enlarge the hole in one of your platters to fit around the step in the motor shaft.
Mount the hard drive motor back in the glued-together casing. Glue the back plate in.

Step 6: Mark the Slots on the Rotors

This is the bit where craft and patience becomes important: It is imperative that the platters are kept flush during the cutting of the slots.

Use the circle-cutter or an engineer's compass to mark 3 circular slots on 4 platters. First, mark out 3 circles or 20mm, 25mm and 30mm radius. Then devide the middle (25mm) circle into 6 equal parts using the compass (set to 25mm if you did not do this while being bored in geometry class).

You now have the 6 drilling points where you will make 10mm holes using the sheet metal drill.

Step 7: Make the Slots on the Rotors

Drill the 6 marked holes on each of the 4 disk platters with a sheet metal drill bit. Do not use a steel drill as you will twist your disk when the bit binds to the thin sheet metal.

Join the holes up so that you form 3 equal slots using a hole file. Finish each curved slot off with a half-round file. Mount the disk in a wooden-clad vice and work as close as possible to the lip of the vice. Be careful not to bend the work piece.

Step 8: Make Disk Spacers

There is a fair bit of interesting math and physics involved which determines how far the disks need to be spaced. Since we are just prototyping here, it is sufficient that the disks are spaced by 2 thicknesses of the average postcard (how scientific is this? Well, that's what the formulas indicate).

So, using the hole cutter, cut at least 12 washers with inner radius 15mm and outter radius of 20mm.

Step 9: Assemble the Rotor

Start by stacking one standard, unslotted disk on the rotor.
Continue the assembly by stacking:
2 paper disk spacers on the rotor shaft.
Then stack slotted disk #1
...2 paper disk spacers
...Slotted disk #2
...2 paper disk spacers
...Slotted disk #3
...2 paper disk spacers.
...Slotted disk #4

Finally, add 2 or more paper disk spacers so that when the disk retaining ring is screwed back on, it will compress the disks so that they won't be able to slide past each other.

Align the slots on the disk with a pencil before tightening the retaining ring.

Step 10: Put a Roof on It!

Cut the top blanking plate from one of the recycled disk drives to the size of your turbine assembly. Make a hole in the middle so that it alligns with the slots when mounted.

Tape the whole thing together using duct tape or whatever tape you have on hand

Step 11: Test It!

Remember that hole you drilled in the side near the beginning of this project? You have probably coverd it up with duct tape. Find the and cut the coverting tape away. Stick a drinking straw into it and blow! The turbine should turn. Slowly.

You will now probably want to hear this thing sing like a canary: Apply a 80PSI air stream to the turbine for 10 seconds for it get up to speed and then listen to the beautiful sound. This one goes up to 22,000 RPM.

Then hold it in your hand and feel Carioli's forces.

Since the disk drive motor is a permanent magnet DC motor, you can also generate a current from it.



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    174 Discussions

    Yes it could. The power generated would be proportional to the efficacy of the turbine (depends how well it is designed and built) and that of the stepper motor of the hard drive (which you obviously would need to rectify to get a useful DC current). And of course the energy of the air that goes into it.


    5 years ago

    I attached a metal frame from the ps2 expansion bay to be a cover for the turbine. I also screwed the sides to it with original screws. The other day I had added wires to the back. I also tested it finally at 65-62 psi


    5 years ago on Introduction

    yoou could solder 2 wires to conntact on motor and start making electricity.(but with 22k rpm you will fry this motor i think)

    13 replies

    Reply 5 years ago on Introduction

    it is a stepper motor with 4 outputs typically, so you will first need to run the 4 outputs into 4 diodes connected to a common positive rail. And as soon as you put a load on that output, the turbine will slow down. Frying will happen if the load's current requirement exceeds the current delivery capability of the motor/generator.

    Could you link me to an article or provide a schematic on how to wire up the motor to generate energy from it... I have a HDD with three disks and I am planning on mounting the platters all together to get (hopefully) more speed... and I am planning on using an acrylic case...

    I have a hose connected to my turbine but I need to know about how much psi at minimum do I need to run it? P.S. it is using three platters that are stacked one on top of another with the spacers at the top and bottom of the platters...

    What the low threshold is before you get any rotation depends on many things. What is the practical value in knowing this in any case? Maybe just go ahead and blow air / water into it and measure it?

    It will just about turn if you blow really hard into it through a straw. But then again, I am a trombone player, so I have no problem doing this.


    Reply 5 years ago

    look at my turbine I added two springs on the hose to prevent it from kinking


    Hey I had a foot pump and clamped down on the tube going to my Tesla turbine so as to build up pressure and when I released it (close to 115 psi) and it spun a little.