Engineers are trained to solve problems, and that often means guaranteeing optimal performance by designing components with extremely tight tolerances and complex features. But when designs move into production, those decisions can introduce added cost, lead time, complexity, and risk.
At A1J Technologies, we frequently help customers across a wide range of industries to review designs before production begins. We help identify design choices that could make manufacturing less efficient, and suggest practical changes to reduce costs.
Below are ten common Design for Manufacturability (DFM) pitfalls we encounter, along with strategies for resolving them through engineering collaboration.
1. Overengineering Tolerances
One of the most common DFM challenges is specifying tolerances tighter than the application requires.
Ultra-tight tolerances may be appropriate for prototypes or highly critical components, but they can significantly increase machining time and production costs.
A1J’s advice:
Start by defining the tolerance required for form, fit, and function, not theoretical perfection. When tolerances are optimized, precision machining becomes faster and more cost-effective.
2. Designing Without Keeping Scalability in Mind
Complex components in low quantities can be difficult, but the real challenge appears when that same part must be produced thousands of times with consistent quality.
A1J’s advice:
Plan for repeatability from the start. Designs should support scalable manufacturing processes that maintain precision across production volumes.
3. Including EDM-Dependent Features
Certain features, such as extremely sharp internal corners, require EDM processes that can add significant time.
Adding radii to those corners, however, can allow the feature to be milled quickly, sometimes in just minutes.
A1J’s advice:
Only require EDM-critical features when they’re functionally necessary. Slight adjustments to certain features can dramatically reduce cost and lead time.
4. Requiring Non-Standard Tooling
Designs sometimes call for unusual radii, thread profiles, or other dimensions that require custom tooling. However, custom tooling increases setup complexity and slows production.
A1J’s advice:
Whenever possible, design around standard tool sizes and thread specifications. Standardization allows our team to move faster.
5. Using Non-Standard Materials
Material specifications are critical, especially in aerospace manufacturing and defense applications. But occasionally, designs reference materials that are unavailable or impractical for the intended geometry.
Lead times for certain specialty alloys can stretch to months.
A1J’s advice:
Discuss material availability with your manufacturer early. Often, equivalent materials with similar performance characteristics are more readily available.
6. Poor Feature Accessibility
Deep pockets and long-reach features can make machining significantly more difficult.
Even when technically possible, they may require specialized tooling that increases cost and machining time.
A1J’s advice:
Design features so that cutting tools can reach them efficiently. Improved accessibility supports faster machining and better surface finishes.
7. Not Properly Accounting for Tolerance Stack-Ups
Some designs attempt to hold extremely tight tolerances on individual components when the final accuracy requirement exists at the assembly level.
Once parts are assembled and fasteners are torqued, small dimensional shifts can occur.
A1J’s advice:
Consider how tolerances accumulate in assemblies. In some cases, machining critical features after assembly can produce better results.
8. Assuming a Specific Manufacturing Process
Designs can be sub-optimal when engineers assume a part must be manufactured using a particular method, such as a single CNC milling process.
However, a vertically integrated manufacturer like A1J Technologies may have multiple options available, including our laser micromachining capability.
A1J’s advice:
Focus on the final functional requirement rather than prescribing the manufacturing method. Experienced manufacturers can often identify the faster, lowest-risk approaches for your projects.
9. Inspection Methodology Isn’t Defined
When tolerances approach micron-level precision, the measurement method becomes critically important.
How the part is fixtured, how probes contact surfaces, how many measurement points are collected, and other factors can all influence inspection results.
A1J’s advice:
Ensure your quality expectations are aligned with your manufacturing partner’s inspection methodologies.
Here at A1J Technologies, our credentials support rigorous quality verification across regulated industries. These include:
- AS9100 certification
- ISO 13485 certification
- ITAR registration
- CMMC-aligned processes
10. Unclear Finishing Requirements
Complex finishing instructions are sometimes missing from drawings and documentation. Masking and coating areas may require clarification during production.
A1J’s advice:
Provide clear visual instructions for finishing requirements whenever possible. Many customers include annotated CAD models or color-coded diagrams to simplify communication.
Early Collaboration Matters in Manufacturing
DFM directly influences:
- Cost efficiency
- Lead times
- Quality
- Supply chain reliability
A1J Technologies works closely with engineering teams to refine designs before they reach the production floor. Early collaboration often reveals opportunities to simplify manufacturing processes, reducing costs for our customers while protecting the part’s performance.
Whether you’re developing a new component or reviewing an existing design, our team is always happy to provide guidance. Reach out to discuss your next project!