Expert-level manufacturing processes covering machining, casting, forming, welding, additive manufacturing, tolerances, and process selection.
Turning: remove material from rotating workpiece with single point tool. Milling: rotating multi-tooth cutter removes material from fixed workpiece. Drilling: rotating tool creates cylindrical hole. Cutting speed, feed, depth: three parameters controlling metal removal rate and quality. Tool materials: HSS, carbide, ceramic, CBN for increasing hardness and temperature.
Sand casting: low cost, complex shapes, rough surface finish, high volume. Die casting: high pressure, good surface finish, close tolerances, metals only. Investment casting: excellent detail and finish, complex shapes, high cost. Shrinkage: metals contract on solidification, design patterns with allowance.
Forging: compressive force shapes hot or cold metal, improves grain structure. Rolling: reduce thickness of metal sheet or bar between rolls. Extrusion: force material through die to create constant cross section. Sheet metal: bending, deep drawing, stamping for flat stock.
FDM: fused deposition modeling, thermoplastic filament, most common desktop printer. SLA: stereolithography, UV-cured resin, high detail, smooth surface. SLS: selective laser sintering, powder bed fusion, functional parts, no support needed. DMLS: direct metal laser sintering, metal powder, aerospace and medical applications.
Tolerance: acceptable range of dimension variation. Clearance fit: shaft always smaller than hole, used for rotation and sliding. Interference fit: shaft larger than hole, press fit for permanent assembly. GDandT: geometric dimensioning and tolerancing, controls form, orientation, location.
| Pitfall | Fix |
|---|---|
| Impossible tolerances on castings | Casting tolerances are much looser than machined parts |
| Underestimating additive manufacturing anisotropy | Parts are weaker in build direction |
| Wrong fit specification | Verify clearance or interference fit intention |
| Ignoring tool access in machining | Design features accessible to cutting tool |