Jet Engine Desk Fan - a free 3D model from Shapekit

A turbofan for your desk, with 20 swept fan blades, a spinner with the classic spiral, stator vanes and a tail cone. It stands on the base of the Turbo Desk Fan and uses the same motor, coupling and speed controller, so you can swap one for the other. Every engine part prints without supports.

Parts (each STL is already placed the right way up for printing)
- jet-engine-fan-nacelle.stl: Inlet, fan case and bypass duct in one piece, with the stator vanes and a Ø42.7 mm motor sleeve in the core. Vents in the core let the motor breathe; the wires leave through the lower fairing. Print: Back end on the bed, inlet up. No supports.
- jet-engine-fan-plate.stl: Screws to the motor's front face (2 × M4 × 8 countersunk) and to the front of the core (3 × M3 × 12 countersunk), so the motor sits at exactly the right depth. Print: Countersinks up. No supports.
- jet-engine-fan-fan.stl: 20 swept blades on a hub that takes a 5 mm flange coupling (4 × M3 × 6). It goes in through the inlet; the set screw is reached through the open front of the hub. Print: Back of the hub on the bed. No supports; good part cooling makes the blades cleaner.
- jet-engine-fan-spinner.stl: The nose cone with the classic spiral. It presses onto the ring at the front of the fan hub. Print: Flat back on the bed, tip up. No supports.
- jet-engine-fan-tail.stl: Core cowl, exhaust nozzle and tail cone, with an air chamber behind the motor and six vent holes that come out in the nozzle. Three filament pins hold it on the core. Print: Front face on the bed. No supports.
- jet-engine-fan-pylon.stl: Holds the engine on the base. The motor wires run down through it. Print: Flange on the bed. No supports.
- turbo-fan-base.stl: The base of the Turbo Desk Fan, with the speed controller and the DC jack. Included in the ZIP. Print: Upside down (top face on the bed), with supports.

Also needed (not printed)
- A 775 DC motor, 12 V: body Ø42 × 66.7 mm, Ø5 mm shaft at least 15 mm long (17 mm is usual), two M4 holes 29 mm apart in the front face.
- A rigid flange coupling for a 5 mm shaft: flange Ø22 mm with 4 × Ø3 mm holes on a Ø16 mm circle, Ø10 mm boss, 12 mm long, M3 set screw. Plus 4 × M3 × 6 pan-head screws.
- 2 × M4 × 8 countersunk screws for the motor, 3 × M3 × 12 countersunk screws for the motor plate.
- 2 × M4 × 25 pan-head screws to fix the nacelle on the pylon (they cut their own thread in Ø3.3 mm holes).
- 4 × M6 × 20 bolts with 8 washers and 4 nuts for the Ø8 mm holes in the pylon flange.
- The same electronics as the Turbo Desk Fan: a 12–24 V PWM speed controller with a knob (5 A or more, M7 pot bushing), a 12 V / 5 A adapter with a 5.5 × 2.1 mm plug and a DC-022B panel jack.
- 3 pieces of 1.75 mm filament, 12 mm long, as pins for the tail; about 60 cm of two-core 0.5 mm² wire; a 1.5 mm hex key.

Print settings: 0.4 mm nozzle, 0.20 mm layer height, 3 walls, 15% gyroid infill, PLA or PETG material.

Assembly
1. Print the parts: The engine parts need no supports. Print the fan with good part cooling for clean blades.
2. Prepare the motor: Solder about 60 cm of wire to the motor. Screw the motor plate onto its front face with 2 × M4 × 8 countersunk screws, the bearing boss in the centre hole.
3. Mount the motor: Feed the wires into the sleeve through the inlet and out of the channel in the lower fairing, then slide the motor in until the plate sits on the core. Fix the plate with 3 × M3 × 12 countersunk screws.
4. Close the tail: Push the three filament pins into the holes at the back of the core and press the tail on.
5. Fit the fan: Screw the flange coupling into the recess at the front of the fan hub with 4 × M3 × 6, boss pointing forward. Slide the fan through the inlet onto the shaft until the hub is about 2.5 mm from the motor plate and tighten the set screw with a 1.5 mm hex key through the open front of the hub. Turn it by hand: it should clear the fan case by about 1.5 mm all round.
6. Fit the spinner: Press the spinner onto the ring at the front of the hub. It pulls off again if you need to reach the set screw.
7. Mount the engine: Set the nacelle on the pylon, pass the wires down through it and screw the two M4 × 25 screws up through the pylon into the nacelle. Fit the controller and jack in the base (see the Turbo Desk Fan), then bolt the pylon onto the base with 4 × M6 × 20, washers and nuts from below.
8. Switch it on: Connect the motor to the speed controller and start slowly. If the air blows forwards, swap the two motor wires.

Safety: The fan spins fast. Only run it fully assembled, keep fingers out of the inlet and start at the lowest speed. Use a plug-in power adapter unless you know how to work safely with mains power.

License: Creative Commons Attribution-NonCommercial 4.0 (CC BY-NC 4.0)
https://creativecommons.org/licenses/by-nc/4.0/
Print it, remix it and share it, as long as you credit Shapekit and don't sell the files or the prints.
