spur gear 3d model

Create a 3D printable spur gear with the following exact specifications: Gear geometry: Type: Spur gear (straight teeth, parallel axis) Number of teeth: 9 Module: 0.8 Pressure angle: 20° Pitch diameter: 7.2mm (module × number of teeth = 0.8 × 9) Addendum: 0.8mm Dedendum: 1.0mm Outer (tip) diameter: 8.8mm Root diameter: 5.2mm Face width (gear thickness): 5mm Center bore — D-shaped shaft hole: Total bore diameter: 6mm Flat chord width (D-flat): 5mm The flat must be parallel to one tooth valley for proper alignment reference Bore must run through the full thickness of the gear (5mm) General design rules: No hub protrusion needed — keep the gear as a flat disc with teeth and central bore No lightening holes — the gear is small and needs full structural integrity Minimum wall thickness between bore and root circle: maintain at least 0.8mm All edges: add a 0.2mm chamfer on both flat faces to improve print quality and reduce sharp edges 3D printing orientation and considerations: Orient the gear with its flat