3D render of the Tesla Turbine: an orange housing ring with its inlet arm between two graphite side covers on a black stand, with a red spoked pulley on the shaft
Free 3D model

Tesla Turbine

Nikola Tesla patented this turbine in 1913, and it has no blades at all. The rotor is a stack of nine flat discs, 0.8 mm apart. Air from a compressor enters at the rim through a flat nozzle, tangent to the discs, and has to spiral inwards to the exhaust holes round the shaft. On its way it drags the faces of the discs along: the thin layer of air on each face sticks to it, and that friction is what turns the rotor. The exhaust leaves through the six ports round each bearing. The shaft is an M8 bolt in two 608 skateboard bearings, and the pulley on its end takes a rubber band or an O-ring as a belt.

  • 17printed parts
  • 11 × 6 × 11 cmassembled (L × W × H)
  • ≈ 0.2 kgfilament in total
  • 108 mmbed length for the housing ring with its inlet arm; the covers need 107 mm, the discs 70 mm
Download all files ZIP · 0.3 MB

Free for personal use under CC BY-NC 4.0: print it, remix it and share it with credit to Shapekit. Please don't sell the files or the prints.

Take it apart in 3D · Parts · How to build it

In 3D

Turn it, take it apart

Every part as you print it. Pick colours to see what your filament will look like.

The 3D model (1.5 MB) loads when you get here.

Preview colours

Housing ring
Covers and stand
Discs, sleeves and collar
Pulley

Drag to rotate · scroll or pinch to zoom

In the download

9 parts, ready to print

Every STL is already placed the right way up. Download them all at once, or one by one.

Housing ring

The ring round the rotor, 0.6 mm clear of the discs, with the inlet arm on top. Inside the arm the air runs from the 6 mm hose socket through a Ø4 bore into a funnel that flattens into a 1 × 16 mm slot; the slot opens into the ring tangent to the rim of the discs.

Size
108 × 92 × 18 mm
Print
Flat, no supports: the bores are teardrops and the funnel bridges itself. 4 walls, so the air channel stays airtight.
Filament
≈ 34 g
STL 0.2 MB

Left cover

The cover on the bolt-head side. A 608 bearing presses into it from outside until it stops on a 45° step. On the inside a 2 mm pocket collects the air from the disc holes, and six ports round the bearing let it out. Counterbores for the six M3 screw heads; the lower part is a leg for the stand.

Size
107 × 92 × 12 mm
Print
Outer face down. No supports.
Filament
≈ 42 g
STL 0.4 MB

Right cover

The same on the pulley side, with hex pockets for the six M3 nuts instead of counterbores.

Size
107 × 92 × 12 mm
Print
Outer face down. No supports.
Filament
≈ 42 g
STL 0.3 MB

Stand

The base plate. The legs of the two covers drop into its slots.

Size
100 × 64 × 6 mm
Print
Flat.
Filament
≈ 26 g
STL 9 KB

Disc × 8

Ø70 × 1.2 mm with a 0.8 mm spacer ring round the bore, so the stack has 0.8 mm gaps for the air. Six kidney-shaped exhaust holes round the middle. The rim has a small chamfer underneath, so the first layer can't squash out wider than the disc.

Size
70 × 70 × 2 mm
Print
Flat, spacer ring up. 0.2 mm layers; they come out solid. They must be flat: print them on a clean, level bed.
Filament
≈ 43 g
STL 0.1 MB

End disc

The last disc of the stack, on the pulley side: the same disc without the spacer ring.

Size
70 × 70 × 1 mm
Print
Flat.
Filament
≈ 5 g
STL 0.1 MB

Sleeve × 2

5.1 mm long, between the disc stack and the inner ring of each bearing. It only touches the inner ring.

Size
11 × 11 × 5 mm
Print
Standing up.
Filament
≈ 1 g
STL 26 KB

Collar

A 1.5 mm washer between the bolt head and the left bearing's inner ring, so the hex head can't rub on the bearing's shield.

Size
12 × 12 × 2 mm
Print
Flat.
Filament
≈ 0 g
STL 26 KB

Pulley

Ø50 mm with five spokes and a V-groove for a rubber band or an O-ring belt. Its hub presses on the right bearing's inner ring, and the nyloc nut on the other side clamps the whole rotor together. The spokes also show you that it turns.

Size
50 × 50 × 11 mm
Print
Spokes down, hub up.
Filament
≈ 8 g
STL 0.2 MB
Also needed

Parts you buy

  • An M8 × 65 hex bolt with a plain shank and 22 mm of thread (ISO 4014 / DIN 931), and an M8 nyloc nut. The bolt is the shaft: both bearings sit on its smooth part.
  • Two 608ZZ ball bearings (8 × 22 × 7 mm), the kind used in skateboards.
  • 6 × M3 × 35 cap screws and 6 M3 nuts.
  • Compressed air: a compressor with a pressure regulator, and either a 6 mm air hose (6 × 4 mm PU tube) or a blow gun with a rubber tip.
  • A little petroleum jelly or silicone grease for the joints of the housing.
  • Safety glasses.
Print settings

Slicer settings

0.20 mmlayer height
4walls
20%gyroid infill
PLA or PETGthe air cools as it expands, so heat is no issue

For a 0.4 mm nozzle. Filament amounts are estimates for these settings.

Assembly

How to build it

Print the parts

Print the nine discs one plate at a time, flat, with nothing else on the bed. Take off any brim and check that each disc lies flat on the table.

Clean the holes

Turn an 8 mm drill bit by hand through every disc, both sleeves, the collar and the pulley, so they slide onto the bolt without play. Push a bearing into each cover from the outside until it stops on the step inside.

Stack the rotor

Put the collar on the bolt, then push the bolt through the bearing of the left cover from the outside. Slide on a sleeve, then the eight discs with their spacer rings away from the bolt head, and the end disc last. Turn the discs so their exhaust holes line up. Then the second sleeve.

Close the housing

Smear a thin film of grease on both faces of the housing ring and set it over the discs onto the left cover, inlet arm up. Put the right cover on, with the bolt through its bearing, and the screws through all three parts from the left. Press the nuts into the pockets of the right cover and tighten the screws evenly.

Pulley and nut

Slide the pulley onto the bolt, hub first, and screw on the nyloc nut. Tighten it until the rotor is clamped: the discs and the bolt then turn as one. Spin it by hand: it must turn freely and keep coasting. If a disc rubs, loosen the nut, turn the discs a little and tighten it again.

Set it on the stand

Push the legs of the two covers into the slots of the stand.

Run it

Put on your safety glasses. Set the regulator to 1 bar, push the hose into the socket on the inlet arm (or press the rubber tip of the blow gun into it) and open the air slowly. The rotor turns anticlockwise, seen from the pulley side. Stay at 3 bar or below.

The rotor spins very fast. Wear safety glasses, keep fingers and loose hair away from the pulley, never run it above 3 bar and stop it if it starts to shake. Compressed air: never point the hose at anyone.

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Open the makers