40mm Extruder fan grille (Wanhao Di3/Maker Select)

thingiverse

I was browsing extruder fan grilles for my Maker Select and found a few options, but each had one major flaw or another. I decided to take inspiration from various designs and create my own improved version. The hexagon pattern is specifically designed with 0.8mm wide ribs, which allows for two nozzle passes using the stock 0.4mm nozzle and minimizes airflow restrictions. Initially, the hex pattern was supposed to span the entire width, but I soon realized its primary purpose: protecting the fan while providing a space for the carriage. However, this design introduced a new challenge - mounting it securely. Other designs feature built-in wells for the screw head, which can affect how much thread engages with the motor body. To avoid using M3x55 or M3x60 screws, which can be hard to find, I opted for a different approach. Some designs use slotted pins, but I found that these tend to break off during printing. Another option was integrating small clips into the design, but this wasn't feasible due to the heat sink and PLA's limitations on the bottom side of the grille. In the end, the only viable solution was press fit - using solid pins that are slightly oversized for an M3 hole, relying on friction to hold the grille in place. The pin diameters match the screw size at the ends but bulge out by 0.25mm in the middle, facilitating insertion and providing a secure hold. The slots around the back edge serve as a removal aid if the fit is too tight. Simply insert a flat screwdriver and twist it so that the slot near the pin gets pulled away. Variations in fan design led me to create two versions of the grille - one for M3 holes and another for M4. Each file is named according to the corresponding screw size, ensuring compatibility with different fans. If you have a standard fan, use the M3 version. The M3 grille I printed fits securely without requiring excessive force, and it hasn't fallen off or rattled during printing. EDIT: The 'b' files include an additional 0.05mm diameter on the thick part of the pins, making for a tighter fit. Print Settings: * Printer: Maker Select * Rafts: Doesn't Matter * Supports: No * Resolution: 0.2mm * Infill: 10% * Notes: Print with 3 shells (1.2mm thickness) and 1.2mm top/bottom to match. The top/bottom thickness provides strength, preventing the grille from bending inward towards the fan hub. Post-Printing: Pin cleanup is necessary after printing. Carefully scrape off any excess material from the pins, ensuring they are smooth and free of blobs before mounting them securely.