Tiếng Việt
Quick answer: First Article Inspection (FAI) means measuring every characteristic on the drawing for the first product from a new production process, to prove the process makes parts to design before mass production. CT3D helps with measurement, drawing ballooning and FAI packages using 3D inspection.
A new mold, a CNC line with new fixtures or a new supplier all carry risk: the product may “look right” but be off in places nobody checks. FAI is the checkpoint at exactly the cheapest moment to fix mistakes, before thousands of bad parts are made. This article takes a practical view: when to do FAI, the specific steps and the documents you need.
What is FAI and when is first article inspection required?
FAI is a complete, documented inspection of one or a few first products, and it should be done whenever there is a significant change in design, process or supply.
Unlike daily sampling inspection, which measures only a few critical dimensions, FAI requires measuring 100% of the characteristics on the drawing: dimensions, geometric tolerances, material notes, surface roughness, heat treatment, painting and plating. In aerospace, the AS9102 standard sets out the FAI forms in detail; the automotive industry has the PPAP process with a similar dimensional results section. Many electronics and equipment customers also require FAI in their own templates.
Typical times when FAI is required:
- First production of a new part number.
- A drawing revision that affects characteristics.
- A new mold, a major mold repair, or moving a mold to another machine.
- A change of supplier, production site or material.
- Restarting production after a long pause.
The FAI process step by step
A rigorous FAI process has six steps, and drawing ballooning and choosing measurement methods decide the quality of the package.
| Step | Work | Output |
|---|---|---|
| 1. Intake | Receive the correct drawing revision, CAD file, customer requirements and marked first samples | Input document list |
| 2. Ballooning | Number every characteristic on the drawing with balloons | Ballooned drawing |
| 3. Measurement plan | Choose a method for each characteristic: 3D scanning, CMM, hand tools, visual check | Measurement plan |
| 4. Measurement | 3D scan, take extra measurements, record results | Measurement data, mesh file |
| 5. Evaluation | Compare measured values with tolerances and rule on each characteristic | Pass/fail results table |
| 6. Documentation | Compile the report, photos, color maps and customer-supplied material certificates | FAI package |
Ballooning: numbering so no characteristic is missed
Ballooning means circling each dimension, GD&T symbol and note on the drawing with a sequence number. Each number matches a row in the results table. This lets the customer cross-check quickly and proves that no characteristic was skipped. General notes such as “burrs no more than 0.2 mm” or “unspecified radii R0.5” also need numbers.
Choosing a measurement method for each characteristic
3D inspection with a scanner suits FAI very well because one scan captures the full geometry, and hundreds of dimensions can then be extracted. Characteristics with very tight tolerances can be measured additionally on a CMM; roughness, paint color and engraved markings are checked with tools and by eye.
How does FAI differ for machined, cast and 3D printed parts?
The FAI principles are the same, but each technology has its own deviation risks, so the measurement focus differs.
| Part type | Common risks | FAI focus |
|---|---|---|
| CNC machining | Wrong stock origin, tool wear, clamping distortion | Hole position, datum faces, fit tolerances |
| Casting (aluminum, cast iron, zinc) | Shrinkage, mold shift, short fill, porosity | Machining allowance, profile, wall thickness |
| Injection-molded plastic | Warpage, uneven shrinkage, sink marks | Flatness, profile, boss and hole position |
| 3D printing (FDM, SLA, MJF, SLM) | Shrinkage, thermal warping, support-related errors, distortion during post-processing | Full geometry, functional surfaces, thin features |
For 3D printed parts, especially SLM metal or MJF plastic used as end-use parts, FAI helps set dimensional compensation factors and build orientation for later batches. This is often overlooked when companies treat 3D printing as just prototyping. You can learn about each technology in our comparison of SLA, FDM, SLS and SLM 3D printing technologies.
What goes into an FAI package?
A complete FAI package usually has three parts: part information, dimensional results, and material and process information.
- Information page: part number, name, drawing revision, lot number, inspection date, inspector, method and measuring equipment used.
- Ballooned drawing: the drawing with every characteristic numbered.
- Dimensional results table: balloon number, characteristic, nominal value, tolerance, measured value, result.
- 3D inspection report: color map compared with CAD, key cross-sections and annotated deviation callouts.
- Material and special process information: material certificates, heat treatment, painting and plating provided by the manufacturer.
- Nonconformance list: failed characteristics, proposed disposition or deviation request.
Note: CT3D prepares the measurement results and 3D inspection report; material and special process certificates are supplied by the manufacturer or customer to attach.
Why use 3D scanning for first article inspection?
3D scanning makes FAI both faster and more complete, because data from one scan can answer questions nobody asked at the time of measuring.
- Complete coverage: extract hundreds of dimensions from the same data set, reducing the risk of missing something.
- Understand the cause: the color map shows whether deviation is systematic (uniform shrinkage, mold shift) or local.
- Keep evidence: the mesh file is stored with the package and can be measured again if the customer asks more.
- Compare FAI rounds: compare T1 and T2 mold samples to judge whether the mold fix worked.
For large parts or molds that are hard to move, CT3D can do on-site 3D scanning at your plant to capture FAI data right on the production floor.
Key points
- FAI measures 100% of drawing characteristics on the first product of a new or changed process.
- Drawing ballooning and measurement planning are the foundation of a reliable FAI package.
- Machining, casting, injection molding and 3D printing each have a different measurement focus.
- 3D scanning makes FAI complete and visual, and keeps evidence for the long term.
FAQ about FAI
How is FAI different from routine sampling inspection?
FAI measures every characteristic once to confirm the process matches the design. Routine inspection measures only a few key characteristics at a set frequency to monitor a process that has already been validated.
How many samples are needed for one FAI?
Usually one representative sample per mold cavity or per process, but the number is set by the customer. Multi-cavity molds usually need one sample from each cavity.
Do 3D printed samples need FAI?
3D printed samples used only to check shape don’t. But if 3D printed parts are used as end-use products, fixtures or master patterns for silicone molds, FAI is worth doing to control shrinkage and deviation.
What if some FAI characteristics fail?
Record the nonconforming characteristics, analyze the cause, fix the process or mold, then run a partial FAI on the affected characteristics. In some cases the customer may accept a written deviation.
Can CT3D prepare FAI reports in the customer’s template?
Yes. The customer sends the template, and CT3D fills in the measurement results and attaches the 3D inspection report. Time and cost are quoted within the working day after we review the drawing.
First article inspection is a small investment that avoids big costs once mass production is running. Send your drawing, CAD file and first samples to CT3D for advice on an FAI approach that fits your process and your customer’s requirements.
Related articles on 3D inspection
- What is 3D inspection? 3D measurement methods, benefits and when to use them
- Industrial CT scanning (3D X-ray inspection): seeing through parts to find internal defects
- 3D inspection in Hanoi and Hai Phong: on-site scanning for factories in northern industrial parks
- Reverse engineering services: a 6-step process, when you need it and a sample prep checklist
The CT3D service ecosystem
- 3D inspection, FAI measurement and 3D scanning
- 3D printing and rapid prototyping services
- SLM metal 3D printing for functional parts
- Silicone molds, vacuum casting and tooling
- Mass production and installation
- CT3D Group
- Contact us for FAI packages
About CT3D – a large-scale, multi-industry prototyping and manufacturing technology company
An FAI package is only worth something when the inspector understands how the product is made. CT3D is a large-scale, multi-industry prototyping and manufacturing technology company that runs 3D printing, mold making, mass production and inspection directly at its workshops in Ho Chi Minh City (Tam Binh and Linh Trung in Thu Duc, and District 6) as well as in Hai Phong. Our in-house chain from 3D scanning, design, 3D printing and molds to production and inspection lets CT3D both measure first articles and propose specific fixes. Companies in any province can contact CT3D at 0975 008 728 or 0985 936 728 (Zalo) and contact@ct3dgroup.com.
Related services at CT3D Group
- 3D inspection service with 3D scanners
- On-demand 3D printing service
- 3D scanning service – high-precision 3D scanning
- CT3D Group network: ct3dgroup.com · in3d.edu.vn – Hotline/Zalo 0975 008 728
