How to Control Injection Mould Costs While Your CAD Design Is Evolving

When a CAD design is still under development, committing to tooling too early can create avoidable costs. Keep the project on budget by agreeing on a defined mold scope, reviewing open design questions before manufacturing begins, and using sample approval as the gate for production. For double shot and overmolding projects, confirm the material pairing and alignment requirements early, then validate the tool with trial runs and dimensional checks.

Start with a Clearly Defined Tooling Scope

Before requesting a final quotation or releasing a mold for manufacture, document the current design status and the requirements that affect tooling. These typically include the two-color injection structure, material combination, alignment tolerances, cavity configuration, expected mold life, and planned production needs. Mark unresolved CAD features as pending engineering review rather than treating them as approved specifications.

This distinction helps separate design development from mold production. A quotation tied to an agreed scope is easier to evaluate and reduces the risk of paying for tooling changes caused by requirements that were not settled at the start.

Confirm Materials and Construction Before Tooling

Double shot overmolding requires careful coordination between the part geometry, the two injection stages, and the selected materials. Longterm lists combinations including ABS plus TPU and PP plus TPE. The design review should also cover precision alignment, optional multi-cavity construction, mold steel, and the intended service life. Product specifications include 718H or 1.2738 steel and a stated lifespan of up to 800,000 shots; confirm that these parameters suit the particular application before finalizing the tooling scope.

For projects with complex geometry or close alignment requirements, allow additional time for engineering review. A simpler mold may follow a shorter development route, while high-precision double shot and overmold tooling generally requires a longer schedule.

Use Sample Checks as a Change-Control Gate

A mold trial provides an opportunity to assess the part before production approval. Longterm's service options include mold trials, dimensional measurement, sample verification, and pre-shipment inspection. For more demanding tools, the listed checks can include CMM testing, surface inspection, and trials across multiple cycles.

Review the samples against the latest approved CAD revision. If measurements, fit, appearance, or alignment indicate that a change is needed, resolve it before authorizing production. This makes sample acceptance a practical checkpoint between tool development and larger manufacturing commitments.

Choose a Service Route That Fits the Project Stage

Different service models offer different levels of support, depending on how mature the design is and whether injection molding or mass production is also required.

Plan the Schedule Alongside the Budget

Lead time is another factor in cost planning, particularly if design updates could affect the mold structure. Longterm lists a 25–40 day delivery window for its custom double shot overmolding mold. Its high-precision custom mold, double shot mold, and overmold service gives a 35–45 working day estimate for complex molds. A separate mold development and plastic injection mass production model lists 25–35 days for mold development, followed by 7–15 days for mass production after sample approval.

These timeframes depend on the selected service route and project requirements. Clarify the schedule assumptions in the quotation, including when the design will be frozen and what approvals are needed before production.

Manufacturing Experience and Quality Support

Longterm reports ISO 9001:2015 certification covering the design, manufacture, and sale of precision molds, as well as the sale of plastic products. Its project examples include an Italian electronic housing mold, a French double shot overmolding project, a US home appliance mold, and an Australian industrial plastic part mold. Customer feedback has referenced dimensional accuracy, surface finish, alignment, stable trial samples, technical support, and delivery performance.

The company also describes an R&D team working on injection mold structure, precision CNC components, sample verification, and process optimization. Its services span OEM mold production, mold making with injection molding, high-precision double shot and overmolding, and mold development linked to mass production.

Frequently Asked Questions

Is it better to wait until the CAD design is final before ordering a mold?

Use engineering reviews to establish which features are approved and which remain open. Before releasing tooling, confirm the two-color structure, material pairing, alignment needs, cavity option, mold steel, and other requirements that affect the mold.

Which inspections can help limit the impact of design changes?

Mold trials, dimensional testing, sample confirmation, and pre-shipment inspection can help identify issues before production release. CMM measurement, surface checks, and multi-cycle trials are also listed for projects with more demanding requirements.

What details should a mold quotation request include?

Share the CAD files or a reference sample, intended materials, mold structure, cavity preference, expected tool life, order quantity, and production needs. Also state whether the quote should cover the mold only, injection molding, or production after sample approval.

Practical Recommendations

To manage injection mould costs while CAD is changing, define the tooling scope, separate unresolved design work from mold release, and approve production only after sample verification. For its custom double shot overmolding mold, Longterm lists a one-set minimum order, a 25–40 day delivery window, compatibility with ABS+TPU or PP+TPE, precision alignment, and mold-trial and dimensional inspection. For project-specific engineering support, contact rogerluo@longterm-mold.com.

About Longterm

Longterm Manufacturing Solutions Limited was founded in 2010 and serves customers in the US, Europe, Australia, and other international markets. Its services include mold design, tooling, precision machining, mold manufacturing, and parts production. The company says its five-engineer R&D team uses UG, SolidWorks, and AutoCAD for mold design, CNC component development, sample verification, and process optimization. Reported capacity is 15–20 injection molds per month and tens of thousands of precision CNC-machined parts, with annual delivery of approximately 180 molds and over 120,000 precision-machined components. Longterm holds ISO 9001:2015 certification and serves customers across several industries.