4" duct and 120mm fan adapters and fittings

thingiverse

NEW in November 2019, a major addition was made to the system with the introduction of the `duct-end-vent` model. This collection brings together adapters that allow for the combination of 4" ducts and 120 mm computer case fans in various configurations. Users can create their own small-scale ventilation systems using readily available parts, perfect for exhausting fumes from devices like 3D printers or soldering irons. ## Components The system consists of several components: Duct Components and Adapters: * `fan-to-duct-inner.scad` attaches to a fan and fits snugly into the end of 4" duct. While the taper often allows for a secure fit, additional materials like tape, glue, or screws may be necessary to ensure a tight seal. If using screws, it's essential to pre-drill the hole to avoid cracking the plastic. * `fan-to-duct-outer.scad` bolts to a fan and matches the size of 4" duct, allowing for tubes designed to fit into 4" duct to be inserted. * `duct-end-vent.scad` is a rigid end-piece that fits into the end of 4" duct, with a square shape on the outside. Its primary purpose was to protect a free end of flex duct and prevent it from rolling. Note that 4" ducts vary in fit, so users may need to adjust sizes or add tape or other fillers for a snug connection. Fan Components: * `fan-louver.scad` provides moderate protection from the elements and fingers for a 120 mm fan mounted on the opposite side of a panel. It would be oversized if used for ducting, but redesigning it is feasible. * `stator.scad` is a simple stator for 120 mm fans. When using two fans in series, placing the stator between them can provide a moderate improvement in performance. Users should print two copies and glue them together, using the 1/4" center hole for alignment while gluing. * `fan-table-edge-clamp.scad` adds a flat plate protruding from an assembly of other 120 mm components, which may be used with a clamp to secure the assembly to the edge of a flat surface perpendicular to the direction of the duct. This design requires improvement, as it lacks tolerances and room for nut/bolt insertion. Also available on GitHub: https://github.com/kpreid/3dp-duct-and-fan-fittings