Spur Gear with Integral Hub

Create a detailed 3D CAD model of a small plastic spur gear with an integral cylindrical hub. Units: mm. Gear dimensions Number of teeth: 12, equally spaced every 30°. Tooth-tip outside diameter: 10.50 mm. Tooth-root diameter: 7.85 mm. Pitch diameter: 9.00 mm. Module: 0.75 mm. Tooth thickness: approximately 1.20 mm. Toothed face width: 7.53 mm. Teeth must be straight, not helical. Hub and bore Hub projects 4.47 mm beyond the toothed section. Total axial length: 12.00 mm. Central through-bore: Ø5.00 mm. Hub outside diameter: provisionally Ø9.00 mm, assuming 2 mm radial wall thickness. Hub, gear body, and teeth must be one solid, concentric part. Hub cross-hole: Ø2.25 mm diametrical through-hole through the cylindrical hub. Hole axis is perpendicular to and intersects the Ø5 mm central bore axis, creating two opposite openings 180° apart. Position the cross-hole axially near the gear-to-hub shoulder. The [nearest edge / centerline] of the hole is 0.40 mm from that shoulder. Do not create axial holes. Use an involute tooth profile if possible. Pressure angle is unverified; use 20° only as a provisional assumption. Preserve all specified dimensions and report conflicts instead of silently changing them. Generate an editable 3D solid and, if supported, export STEP and STL files. Also provide front, side, and end views.

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.