Hva endrer det tekniske valget
Plastic gears can be molded or machined, but the route changes how tooth geometry, hubs, shrinkage and finishing are controlled.
Molding suits repeat geometries and can integrate hubs or features. Machining is flexible for lower quantities, larger sizes and stock-form polymers, and it allows direct cutting of tooth forms without mold shrinkage.
Machined gears are especially useful when tooth geometry is still changing or when the selected polymer is available as stable stock. Molded gears become attractive when the design can be optimized around repeat production and integrated features. The two routes can also be combined: a gear body may be molded and a bore or face finished afterward. That hybrid route only helps when the secondary datum is defined relative to the tooth form.
Tegnings- og applikasjonsdata
Review module/DP, tooth count, face width, bore, hub/web thickness, material grade, quantity and the inspection class required by the mechanism.
Legg disse inndataene på den kontrollerte tegningen, spesifikasjonen eller vedlegget til tilbudsspørsmålet der det er mulig. Å holde dem unna uformelle meldingstråder gjør det enklere å håndtere leverandørsammenligninger og senere revisjoner.
En vanlig feilkilde
A molded gear copied directly from a machined design can inherit wall and hub transitions that are poor for filling or cooling.
Hvordan bevise designet
Validate the final production route with the mating gear and the intended center distance.
For Injection Molded vs Machined Plastic Gears, close the DFM loop by updating the controlled CAD/drawing and sample plan. A recommendation that never reaches the released revision cannot be inspected consistently in production.
Leverandørbrief
Before requesting a price for injection molded vs machined plastic gears, identify the current drawing revision, production quantity, material constraint and the feature that most strongly affects function. Ask the supplier to flag any deviation from those inputs in the quotation so technical alternatives stay visible.
Praktisk designgjennomgang for denne avgjørelsen
Compare annual quantity, revision maturity, feature access, surface/finish requirements and tolerance strategy before choosing the process. Molding can integrate features and repeat high volumes, while machining can be faster to change and practical for larger stock shapes or lower volumes. Secondary machining can also be used on a molded datum when the economics and tolerance stack justify it.
Registrer forutsetningene på tegningen eller i tilbudsforespørselen slik at leverandøren kan bekrefte dem før tilbudet gis. Når en verdi er ukjent, identifiser den som en åpen konstruksjonsvare i stedet for å kopiere et generisk katalognummer som kanskje ikke samsvarer med monteringen.
Verifiseringsark
- Annual demand and batch size
- Expected design changes
- Features that require tool access or slides
- Datums that may need secondary machining
- Material form / exact grade constraints
- First-article and change-control plan
Bruk den første prøven til å lukke disse punktene med både dimensjonsdokumentasjon og relevant funksjonskontroll. Eventuelle aksepterte avvik bør fanges opp i den kontrollerte revisjonen før gjentatt produksjon.
