Centrifugal Blower Assembly (No Fillets)

Create a parametric centrifugal blower for the condenser side of a portable AC unit. Target approximately 300–350 CFM. The assembly should include a backward-curved impeller, spiral volute housing, removable inlet cover, and motor mount as separate components. Impeller: 200 mm OD, 40 mm wide, 100 mm inlet eye, 40 mm hub, 8 mm shaft bore, 12 equally spaced backward-curved blades, 3 mm blade thickness, and about 35° backward outlet blade angle. Use a 3 mm rear shroud and optional front inlet ring. Add small fillets where blades meet the shrouds. Volute housing: use a true expanding spiral, not a constant-radius circle or ellipse. Impeller radius is 100 mm. Start the inner housing radius around 110 mm near the tongue and increase smoothly to about 160 mm near the discharge over one revolution. Approximate the profile with: r(θ)=110+8θ with r in mm and θ in radians. Housing internal width should be about 45 mm with 3–4 mm wall thickness. Maintain 2–3 mm axial clearance around the impeller and approximately 8–12 mm minimum radial clearance near the tongue. Create a rounded cutoff/tongue with approximately 4 mm nose radius. The volute should transition smoothly into a tangential rectangular outlet approximately 100 mm × 45 mm. Extend the outlet duct 75–100 mm and add a mounting flange. Create a centered circular inlet approximately 105 mm diameter with a smooth bell-mouth entrance. Split the housing into a main scroll body and removable front cover using M4 bolt holes around the perimeter. Add a removable rear motor mounting plate with centered shaft opening and editable 4-hole motor bolt pattern. Make the design suitable for FDM 3D printing and easy experimental modification. Keep the impeller removable so different blade counts, blade angles, and impeller geometries can be tested in the same housing. Make these dimensions parametric: impeller diameter, width, blade count, blade angle, blade thickness, inlet diameter, shaft diameter, tongue clearance, volute start/end radius, housing width, and outlet dimensions.

Parameters

Every value above is a live dimension. Open a model like this in the editor and each one becomes a slider you can drag before exporting.