From Drawing to Reality: What Product Designers Need to Communicate to Precision Engineers

Posted on by Tadhg Hurley

In precision manufacturing, one common misstep can derail an otherwise brilliant product design: assuming that a drawing alone conveys all necessary information.

At MAAS Precision, we frequently work with design teams across medtech, photonics, robotics, and advanced manufacturing sectors. And while we welcome detailed CAD files and 2D drawings, we’ve learned over decades that the real success of a component depends not just on geometry, but on context.

To truly move from concept to manufacturable reality—especially one that can scale profitably—engineers and designers need to communicate a broader set of data, assumptions, and constraints from the outset.

Here’s a breakdown of what we look for—and what you should always include when engaging with a precision engineering partner.

1. Design Intent: Communicate the "Why"

A drawing shows what the part looks like. But unless we know what the part does, we’re operating with blind spots.

Let us know:

  • The function of the part in its assembly

  • What areas are critical to performance

  • What features are purely cosmetic or non-critical

  • If the design is still fluid or locked

This information helps us make smarter suggestions on geometry, tolerances, material selection, and manufacturing methods—especially when there’s room to reduce cost or improve repeatability.

2. Critical Dimensions and Functional Tolerances

Over-tolerancing is one of the most common (and expensive) issues we see.

For example:

  • A ±0.01 mm tolerance may be achievable, but it requires extra machining time, more frequent inspections, and tighter process control—all of which increase cost.

  • Often, the application doesn’t require such tight control. If ±0.1 mm is acceptable, say so. We’ll manufacture accordingly.

Be clear about:

  • Which dimensions are critical to fit, function, or alignment

  • Which are aesthetic or can be controlled less tightly

  • Whether geometric tolerances (GD&T) are required and why

3. Overall Envelope and Assembly Constraints

If a part is designed to fit inside a larger system, define:

  • The maximum allowable envelope

  • Assembly stack-ups and fit conditions (interference, clearance, transition)

  • Whether the part is manually or robotically assembled

  • Orientation and installation method

We can often machine features that aid assembly (chamfers, lead-ins, alignment pins) if we understand the full picture.

4. Materials: Beyond Just the Grade

Stating "316 stainless" or "Aluminium 7075" is a good start—but material selection should consider:

  • Machinability

  • Availability

  • Surface finish requirements

  • Mechanical or thermal properties

  • Post-processing (anodising, passivation, heat treatment)

Let us know why a material was chosen. In some cases, we can suggest a more suitable or cost-effective alternative.

5. Colour, Finish and Cosmetic Requirements

Finish matters—especially for medtech or customer-facing products.

Communicate:

  • Surface finish requirements (Ra values, polished vs. machined vs. bead-blasted)

  • Anodising or plating colour specifications

  • Visual inspection standards (if applicable)

  • If parts are critical for cleanroom, biocompatibility, or corrosion resistance

Cosmetic specs often impact fixturing, tooling, and secondary operations.

6. Scaling Assumptions: Prototype vs. Production

Designing a part to be machined once is very different from designing it for scale.

Tell us:

  • Whether this is a proof-of-concept or heading for volume production

  • Expected annual quantities

  • Any planned changes before tooling or automation is introduced

We can help de-risk scale-up by flagging features that are expensive now but unnecessary later—or suggesting changes that reduce setup times, tool wear, or waste at scale.

7. Assembly and Fit Requirements

Parts don’t exist in isolation. Understanding how your component interacts with others in the system helps us make better decisions.

Be specific about:

  • Press fits, slip fits, or locational fits (and relevant ISO fits where applicable)

  • Thread engagement requirements

  • Coaxiality, flatness, or perpendicularity requirements across mating surfaces

  • Any sealing, bonding, or welding planned

Why This Matters

Precision engineering is not just about cutting metal—it’s about transferring the essence of a design from screen to spindle without compromise.

At MAAS, our machines and machinists are top-tier—but the real value comes from decades of experience helping companies refine and optimise their designs before chips start flying. We’ve helped products evolve from rough prototypes into clean, repeatable, margin-friendly components ready for market.

And we’ve seen where designs fail—not due to flaws in intent, but due to gaps in communication.

If you're designing a new product, or iterating an existing one, don’t stop at the drawing. Start a conversation with your manufacturing partner early—and carry it all the way through.

Need help turning your prototype into something scalable and manufacturable?
Talk to us early. You’ll save time, budget, and plenty of back-and-forth.

#DesignForManufacture #PrecisionEngineering #ProductDesign #PrototypeToProduction #MedTech #Photonics #Robotics #ManufacturingInsights #DFM #MAASPrecision