Replacement plastic parts without a drawing

Reverse engineering for replacement plastic parts.

A worn, damaged or obsolete plastic part can begin a replacement project. CDS captures existing-part dimensions and geometric features and prepares documentation using the sample and available records. Required tolerances come from the customer or controlling specification.

Contact us with the part you have, even if its drawing is missing or incomplete.

Photography plannedExisting plastic part and reference features
A sample can preserve useful geometry even when the original drawing is unavailable.

Start with the information available

The sample and the records can fill different gaps.

Old documentation may preserve a dimension that wear has removed. The part itself may show connections or mounting features that are missing from the paperwork.

A drawing or partial specification

A current drawing and revision can control the replacement. Sketches, CAD information, old specifications, part numbers and reliable measurements may supply additional detail when the definition is incomplete.

The controlling requirements need to remain clear when records disagree with the existing part.

A physical sample

The part provides geometry and clues to its installed position. Known-good faces, mounting points and mating components can help establish which features remain useful references.

Dimensional capture documents existing features. Required dimensions and tolerances that the sample cannot establish need supporting records or customer clarification.

Wear, damage and mating interfaces

A worn feature may no longer show its required dimensions.

Wear, distortion, repairs and modifications can change the part. Identify those areas and provide reliable dimensions or original records where available.

Known-good, worn and uncertain sample featuresA symbolic sample has an intact left reference face, an irregular worn right edge and an uncertain area beyond it. A separate mating component below represents assembly information. No original dimensions or restored profile are shown.?Known-good faceObserved wearUncertain areaMating componentSample condition and missing information1 is an intact reference face, 2 an observed worn edge, 3 an uncertain area, and 4 a separate mating component. The original profile is not assumed.?1234
  1. Known-good face
  2. Observed wear
  3. Uncertain area
  4. Mating component
Intact surfaces, observed damage and missing information are different references. The original profile and required clearance still need to be established for the actual part.

Intact reference features

Undamaged faces and known mating dimensions can help document an existing component. They do not establish every original dimension.

Changed or damaged features

Worn edges, broken sections, repaired areas and modifications need to be distinguished from the intended geometry.

Missing requirements

Required fit and acceptance criteria come from the buyer, equipment owner or controlling specification. Measuring a sample alone cannot recover design intent or guarantee fit and performance.

Photography plannedWorn edge and intact reference surface
The worn area and intact surface show different conditions on the same part.

Material cannot be identified by appearance alone.

Color and appearance do not establish resin, grade, reinforcement, compliance status or service history. Provide the existing material specification, including any controlled grade, brand or filler. Missing material requirements need customer clarification.

Reverse engineering documents an existing part for manufacture. A material change or revised component needs a customer-approved specification; CDS does not provide component design or application validation.

Replacement documentation

Keep the part requirements connected to future orders.

CDS supports single replacement parts through recurring production runs, subject to project requirements.

Part specifications and CAD files maintained for future orders.

For a repeat order, confirm the current revision, quantities and acceptance requirements. Discuss any files or documentation you need with CDS.

From part definition to machining

The component's material and geometry determine whether CNC milling, CNC turning or a combination is appropriate. Review CDS's plastic machining services for details on milling and turning.

CDS evaluates manufacturing feasibility against the part geometry, material and required fit before the replacement work can proceed.

Request a replacement part

Tell us what needs replacing.

Describe the part, its condition and the information you have. Identify whether you need an unchanged replacement or have a customer-specified revision.

Part and condition
Available drawing, specification, sketch, CAD information, part number or sample description, with revision status. Identify known-good, worn, broken, repaired, modified and uncertain features.
Required dimensions
Known dimensions, reference faces, mating dimensions and tolerances from the customer or controlling specification. Identify which records govern where a drawing and sample disagree.
Material and order
Specified material and grade, required records, quantity now, possible recurring demand and requested timing. Identify unresolved material details for clarification.