Gears and transmission
Engine Crankcase Casing Half
- Bounding box
- 304.3 × 254.3 × 87.2 mm
- Engine
- Precision B-rep
- Parameters
- 19
- Published
- October 8, 2026
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The prompt
Generate a 3D CAD model of a custom mechanical engine crankcase casing (one half side) designed for CNC milling from a raw aluminum block. Overall Raw Block Dimensions: - Length: 280mm - Width: 230mm - Thickness: 75mm Key Features & Internal Pockets: 1. Top Deck: Features a large central cylinder boring hole (crankcase bore) with a diameter of 132mm, opening directly into the main crankshaft chamber. 2. Internal Pocket 1 (Crankshaft Room): A circular chamber with a diameter of 114mm centered directly underneath the top deck cylinder bore. 3. Internal Pocket 2 (Transmission Room): An asymmetrical, multi-level gearbox pocket adjacent to the crankshaft room to house transmission gears. 4. Bearing Journal: A high-precision circular through-hole at the center of the crankshaft room with a nominal diameter of 72mm for the main crankshaft bearing. 5. Outer Profile: The top deck remains at full width (230mm), but the lower outer walls must taper down and transition into a narrower, organic curved flange outline that matches a standard motorcycle engine side cover layout. 6. Mounting Bosses: Include thick mounting bosses (minimum 12mm thickness) with flat faces along the perimeter of the outer flange for case-matching bolts. 7. Fillets & Radii: Apply a minimum fillet radius of 4mm to all internal pocket corners and wall transitions to eliminate sharp 90-degree edges for CNC tool accessibility. Output requirements: Valid manifold solid geometry, clean B-Rep structure, exportable to STEP or IGES format.
Parameters
| Name | Value | Range |
|---|---|---|
| Overall Length | 280 mm | 200 – 400 |
| Overall Width | 230 mm | 150 – 350 |
| Overall Thickness | 75 mm | 40 – 120 |
| Top Deck Thickness | 20 mm | 10 – 40 |
| Crankcase Bore Diameter | 132 mm | 80 – 180 |
| Crankcase Bore Depth | 20 mm | 5 – 40 |
| Crankshaft Chamber Diameter | 114 mm | 70 – 150 |
| Crankshaft Chamber Depth | 35 mm | 10 – 60 |
| Bearing Journal Diameter | 72 mm | 30 – 100 |
| Transmission Offset X | 110 mm | 70 – 120 |
| Transmission Offset Y | 0 mm | -40 – 40 |
| Transmission Pocket Length | 50 mm | 20 – 80 |
| Transmission Pocket Width | 45 mm | 20 – 80 |
| Transmission Pocket Depth | 25 mm | 5 – 45 |
| Bottom Flange Length | 240 mm | 180 – 270 |
| Bottom Flange Width | 120 mm | 80 – 200 |
| Boss Protrusion | 12 mm | 5 – 25 |
| Boss Width | 40 mm | 10 – 60 |
| Fillet Radius | 4 mm | 1 – 8 |
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.
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