Wind Cannon: PWM Fan Housing for Wind Simulator

The Wind Cannon is an engineered 3D printable housing configured to hold 2 pulse width modulation (PWM) fans (120mm & 200mm fans). PWM fan output can be linked to PC simulation/game telemetry via an Arduino to create what is commonly referred to as a “wind sim,” which forms the basis of this project. This publication is intended to provide a PWM fan housing and blueprints to create a high-powered kit suitable for intense wind simulation (e.g., in connection with sim racing, flight sims, etc.). However, it's a very cool, over-the-top fan/blower to have as well that keeps users cool with a high velocity breeze.

NOTE: This base design is free, which has limited (but still awesome) airflow performance due to nozzle and diverter geometries. Please support these efforts by purchasing the computer-optimized nozzle and diverter pieces (linked below), which increase airflow performance by about 40% to achieve outlet velocity near 30 MPH while substantially reducing fan noise.

Link to optimized components:
https://cults3d.com/en/3d-model/gadget/wind-cannon-upgrade-optimized-nozzle-and-diverter

DISCLAIMER: THIS IS AN EXPERIMENTAL, HIGH-PRESSURE AND HIGH-VELOCITY DEVICE. USE AT YOUR OWN RISK. HEED ALL SAFETY PRECAUTIONS BELOW OR INJURY MAY OCCUR.

PROTOTYPE TEST VIDEO:
https://www.youtube.com/watch?v=hBZtEzegXDE 

PRINTER REQUIREMENT: FDM printer able to accommodate pieces roughly 250mmx250mmx250mm in size is required. Ender 3 S1 Plus was primarily used for the prototype. Nozzle was printed using Bambu Labs P1S. Housing was printed using Creality K2 Plus.

FEATURES:

• Housing sized to hold (a) one 120mm PWM fan and (b) one 200mm PWM fan. Compatible with a wide range of PWM fans that can fit in housing (see sheets 2 & 3 of drawing)
• 14 printed pieces total, using about 2kg of filament (I used PLA)
• All pieces are no-support designed. Prototype was successfully printed without supports.
• Walls were designed with 0.4mm nozzles in mind (wall thicknesses are multiples of 0.4)
• Variety of mounting options including VESA 100x100, 75x75, and 8mm diameter center hole that can accommodate camera stands.
• Optional fan safety grille (recommended), which may reduce system performance. 

SPECS (if using the fans linked below):

• Total weight (when assembled): ~ 5.5 lbs.
• Max measured nozzle outlet velocity: ~ 22 MPH @ ~300 CFM.
• Max operating noise: ~ 70dBA @ 2 FT.

ASSEMBLY: Use a heavy, tip-resistant bowl to facilitate assembling pieces and hardware (shown in pic). The inlet_cap piece can safely sit centered on a bowl with its cone facing in the bowl.

Handles- after the housing and nozzle pieces are fastened together, the entire assembly can be safely placed on your lap long-ways (or on a carpet) while installing the handles, such that the housing can roll back and fourth on your lap. The handles are tricky and require patience in positioning all 8 screws via the handle access holes (see sheet 3 of drawing).

Assembling all pieces properly will take at least 3-5 hours (at least for me), involving about 100 pieces of hardware.

HARDWARE: Hardware (i.e., nuts and bolts) should be M3 or #6 sized. The attached drawing PDF indicates all bolt depths and hole sizes, for reference. I used mostly #6 and the fit was very nice. For the connection between the diverter, the 120mm fan, and the fan chassis, I recommend M3 X 160mm long fully threaded rods. Listed below is what I ended up using:

• M3 x 160mm threaded rod (qty. 4)
• No. 6 x 2 inches machine screw (qty. 4)
• No. 6 x 1.5 inches machine screw (qty. 4)
• No. 6 x 1.25 inches machine screw (qty. 4)
• No. 6 x 1 inch machine screw (qty. 8)
• No. 6 x 0.75 inches machine screw (qty. 4)
• No. 6 x 0.5 inches machine screw (qty. 6)

[please comment if the above hardware sizes or quantities are inaccurate]

Further, each hardware connection should include at least one locking element (e.g., split lock washer, jam nut, etc.), if possible. Otherwise, the high RPM fan could loosen the hardware connections over time due to vibrations (haven't done long-term testing yet).

Link to my original thingiverse post which may contain additional photos: https://www.thingiverse.com/thing:6682974

OTHER: Note if housing outer walls warp during printing and do not sit flush (like mine). Wedging a small strip of acoustic foam between worked perfectly (see pics).

Finally, in the attached drawing PDF, all dimensions are in mm.

LINKS TO VALIDATED FANS: Bluegears Bgears b-BlasterPWM 120x38 2Ball PWM High Speed Fan: https://amzn.to/4d2lRiR

Thermaltake 200mm Pure 20 Series Black 200x30mm: https://amzn.to/47mH0TD

WIND SIM SETUP:

https://www.simhubdash.com/community-2/projects/wind-sim-with-arduino-uno-rev-3-and-arduino-motor-shield-rev-3/

OR:

Generic variable PWM controller (rated for 12VDC and at least 4 Amps).

SAFETY PRECAUTIONS (PLEASE READ ALL POINTS BELOW PRIOR TO USE):

• DO NOT AIM DEVICE DIRECTLY AT FACE WITHOUT EYE PROTECTION.
• DO NOT PLACE ANY OBJECT(S) DIRECTLY IN, NEAR, OR AROUND FAN INLET.
• POTENTIAL SHRAPNEL HAZARD IF OBJECT(S) CONTACT OR ENTER FAN INLET.
• POTENTIAL PROJECTILE HAZARD FROM DIVERTER CONE IF MISPRINTED OR DAMAGED DURING ASSEMBLY. CAREFULLY INSPECT PRINTED PART(S) AND HANDLE WITH CARE.
• DO NOT TOUCH FAN BLADE(S) WHEN IN OPERATION.
• KEEP OUT OF REACH OF CHILDREN AND ANIMALS.
• 200MM FAN REACHES ANGULAR SPEEDS UPWARDS OF 2,000 RPM AND WILL LACERATE.
• IT IS RECOMMENDED TO MOUNT THE DEVICE AT AN ELEVATED POSITION, AIMED AT USER'S CHEST OR SHOULDER (E.G., USING A TALL VESA POLE MOUNT).
• USE AT YOUR OWN RISK

Notes:

• Diverter_w_cone should have 100% infill (thin walls and hollow). Handles and VESA_mtg_bracket at least 25-30% infill for strength. All other parts I used between 15%-20% infill. If you want to save filament on the fan chassis, use a 2 line wall count in the slicer.
• Consider using lines or grid infill pattern with parts angled on the build plate to create internal structural trusses.
• All pieces are no-support designed for FDM printers.