AS 91622 Annotated exemplars

This annotated exemplar is intended for teacher use only. Annotated exemplars are extracts of student evidence, with commentary, that explain key parts of a standard. These help teachers make assessment judgements at the grade boundaries.

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For Excellence, the student needs to efficiently implement complex procedures to make a specified product using a Computer Numerical Controlled (CNC) machine.

This involves undertaking procedures in a manner that economises time, effort, tooling, and materials.

Across the sample, the workflow demonstrates that procedures were undertaken in a way that economised time, effort, tooling, and materials alongside independence, consistent accuracy, and informed decision‑making.

Multiple test cuts and engravings were carried out to determine optimal cutting speeds, engraving speeds, and power settings. The evidence explicitly states that this testing process avoided re‑cuts and prevented material waste, directly showing economy of time, effort, tooling, and material. These actions align closely with the Excellence expectation for efficient implementation.

Further evidence (1) demonstrates that machine parameters were adjusted to optimise quality, indicating purposeful problem‑solving rather than basic completion of tasks. Test outcomes were evaluated, and refinements were made to reduce material waste, improve cut quality, and preserve usable stock. This reflects deliberate efficiency in the management of CNC processes.

Additional evidence (2) shows that the chessboard was designed first, an approach that reduced the likelihood of re‑cutting pieces. By establishing accurate dimensions early, the subsequent piece production process was streamlined, and the risk of wasting time due to limited CAD experience was minimised.

Understanding of CNC laser limits is also integrated throughout the workflow. Evidence (3) shows that starting points were selected to minimise waste, and template‑based approaches were used to ensure consistency and prevent rework.

Designing a custom cutting template (4) further reduced the risk of alignment errors and accelerated production by maintaining consistent positioning across repeated cuts. These decisions demonstrate a sustained focus on reducing both material consumption and processing time.

The evidence also shows iterative cycles of testing, evaluating, refining, and implementing, which collectively demonstrate efficient management of complex CNC procedures. For example, pieces were grouped and rotated to maximise use of the available board area, reducing off‑cuts and avoiding wasted material (5). This nesting behaviour is a clear indicator of efficiency within the workflow.

Overall, the sample crosses the Excellence threshold because it shows multiple instances where procedures were implemented efficiently. To secure the grade, the evidence would need to make these efficiencies clearer and more comprehensive across the full process. For example, briefly logging defect‑prevention actions and the defects avoided, justifying the cut order (engrave before cut to avoid movement, thin features last), including nesting screenshots with yield calculations, and/or documenting machine bookings met without overrun. Some aspects of efficient practice are implied rather than explicitly demonstrated.

For Merit, the student needs to skillfully implement complex procedures to make a specified product using a Computer Numerical Controlled (CNC) machine.

This involves showing independence and accuracy in undertaking the procedures.

Evidence (1) indicates that the CNC machine was set up and operated independently, with the teacher’s comment confirming this level of autonomy. Further evidence of independence appears in screenshots showing zeroing offsets and the import of G‑code into CNC.js (2), demonstrating control of the workflow without prompted support.

Accurate CNC setup and toolpath configuration are shown through documented measurements for the T6 and T10 bits (3), indicating attention to correct tooling requirements.

Troubleshooting skills are demonstrated within the machining process. When the thumb holes did not cut through during an earlier machining pass, the evidence (4) shows identification of the cause and an adjustment from the original contour toolpath. Evidence from a final test route (5) further demonstrates refinement and problem‑solving prior to committing to the full machining of the steering wheel, indicating controlled and iterative accuracy improvements in the CNC process.

Evaluation evidence (6) offers a concise but accurate comparison between the final product and the CAD model, noting bore‑hole spacing, smooth edges, correct toolpath execution, and ergonomic considerations. Additional comparison images (7) show that board movement caused errors in an earlier attempt, which were addressed in route 2 by increasing clamping and correcting the retract height. This visual documentation demonstrates the ability to assess machining accuracy, identify causes of error, and implement corrective measures—key aspects of skilful implementation at the Merit/Excellence boundary.

To reach Excellence, the outcome must show not only independence and accuracy but also efficiency and a high level of finish without inconsistencies. Excellence requires evidence that CNC procedures were carried out in an economical and strategic manner, such as optimised toolpaths, minimised material waste, reduced re‑cuts, and deliberate material layout choices. The process needs to be purposeful and streamlined rather than reliant on trial‑and‑error, with explicit commentary on how these decisions improved efficiency and contributed to a refined, accurate final product that aligns with the specifications and the graphic representation.

The teacher comment explains why the evidence does not reach Excellence, noting that the evaluation required strengthening, that accuracy in the machining route could be improved, and that the explanation of efficiency, tooling decisions, and material‑use justification was not yet at the depth required for an Excellence judgement.

For Merit, the student needs to skillfully implement complex procedures to make a specified product using a Computer Numerical Controlled (CNC) machine.

This involves showing independence and accuracy in undertaking the procedures.

The evidence demonstrates that complex procedures were implemented with independence and accuracy, as required for Merit.

The digital workflow shows understanding of machine envelope limits and appropriate file handling (1). This is seen in the duplication of the workspace, scaling of the model to fit and exporting of individual components as STL files. These actions indicate accurate management of file types and preparation suitable for a CNC process such as 3D printing.

Further independence is shown through the upload of files into UP Studio (2), where parts were rotated and positioned to reduce support and printing time, providing evidence of thoughtful optimisation decisions.

Technical accuracy is demonstrated through explanations of key slicer settings and their functional impacts. The evidence shows understanding of parameters such as quality and layer thickness, infill percentage and type, and nozzle offset (3), indicating a sufficient grasp of how digital settings influence printed output. Accuracy checking is also evident through the use of calipers to measure output dimensions and compare these to CAD data. The identification of a 1 mm discrepancy and a plausible explanation strengthen this evidence of accuracy monitoring (4).

Risk management is evident through notes that identify key process risks such as filament issues, heating requirements, and warping or detachment from the build plate. Associated mitigations, bed cleaning, fit checking, ventilation, and periodic monitoring, provide further evidence of independent management of factors that influence print reliability (5).

However, while the evidence includes visual checks and verification of scale (6), it does not reference or evaluate the product against a complete CNC output specification. Missing elements such as dimensional tolerances across multiple features, surface quality expectations, support removal criteria, or performance of bridging limit the evaluative depth to a low Merit level.

Taken together, the evidence supports a boundary Merit judgement, as the overall technical depth is uneven, and optimisation decisions lack detailed justification. Stronger evidence could be achieved by including explicit machine parameters such as nozzle and bed temperatures, filament specifications, and clearly defined acceptance criteria for printed quality.

These omissions, also noted in the teacher commentary, cap the level of evaluation at low Merit (7).

For Achieved, the student needs to implement complex procedures to make a specified product using a Computer Numerical Controlled (CNC) machine.

This involves:

• integrating the limits of a CNC machine into a graphic representation of the desired product in a computer design setting that demonstrates an understanding of CNC programming language
• setting up and calibrating a CNC machine to software and manufacturer requirements
• operating a CNC machine to make a product in compliance with relevant health and safety regulations
• evaluating a CNC machine-made product against its graphic representation.

Evidence (1) shows clear awareness of the 3D printer’s bed size, height limits, and compatible file types such as STL. This confirms that the part was checked against the machine’s physical capabilities and that appropriate file formats were used. These observations meet the Achievement requirement to integrate CNC machine limits into the graphic representation.

Further evidence (2) demonstrates correct setup and calibration of the CNC/3D printer. This includes the selection of a 200°C nozzle temperature and a 60°C bed temperature, testing of motors and feed rates, adjustment of the nozzle, and checking that the digital file was suitable for printing. These documented actions reflect an accurate preparation process.

Health and safety expectations are also met.

Evidence (3) shows analysis of relevant risks, including fire hazards, burn risks, exposure to toxic gases, and the need for maintaining cleanliness around the printer. These considerations indicate compliance with standard CNC operating and safety procedures.

Additional evidence (4) evaluates the fabricated product against the original CAD model and shows that the printed output matched 1:1 dimensions, exhibited no warping or cracking, and allowed the metal pipe component to fit securely. This demonstrates that the printed product met the intended functional requirements.

Teacher comments (5) confirm the Achieved judgement and provide reasons why the evidence does not reach Merit. These comments note missing details related to printer initialisation, nozzle offset, skilled procedural tips, and deeper explanations of layer choices and settings.

The absence of such detail limits the demonstration of independence and accuracy that is required for a Merit judgement.

To strengthen the evidence toward Merit, more detailed explanations of procedures, clearer justification for selected settings, and documentation of troubleshooting or parameter refinement would be needed. Inclusion of photographs or annotated screenshots showing depth in machine setup and calibration would also support a stronger claim of skilful implementation.

In evaluating the printed outcome, evidence could extend beyond general statements such as “1:1 replica” or “rigid” by addressing dimensional tolerances, surface quality measures, areas for improvement, and the effects of specific parameters on print quality. Expanding these areas could provide the independence and technical accuracy needed to meet the Merit criteria.

For Achieved, the student needs to implement complex procedures to make a specified product using a Computer Numerical Controlled (CNC) machine.

This involves:

• integrating the limits of a CNC machine into a graphic representation of the desired product in a computer design setting that demonstrates an understanding of CNC programming language
• setting up and calibrating a CNC machine to software and manufacturer requirements
• operating a CNC machine to make a product in compliance with relevant health and safety regulations
• evaluating a CNC machine-made product against its graphic representation.

The evidence shows that all four Achievement criteria are met, but that the sample sits at Low Achieved due to limited depth in CNC/CAM control, surface‑level accuracy descriptions, a hazard that was not proactively prevented, and an evaluation that lacks quantified measures.

Evidence (1) shows that machine limits have been integrated into the graphic representation. CNC constraints such as limited tool bits, time, bed size, and material availability were identified, and their impact on project scope and the selection of imagery for an inlay was explained. This shows awareness of the machine limits that influence design decisions.

Further evidence (2) demonstrates that the CNC machine was set up and calibrated in accordance with software and manufacturer requirements. Documentation shows basic steps and indicates that calibration occurred, though the depth of explanation remains limited.

Evidence (3) confirms operation of the CNC in alignment with health and safety expectations. Hazards and precautions such as dust extraction, hearing protection, safety glasses, and aprons were listed and supported with photographic documentation of PPE and control measures.

The evaluation evidence (4) shows comparison between the fabricated outcome and the graphic representation. The inlay is noted as fitting with no visible gaps, and curved detailing is identified as challenging for the router to cut cleanly. A setup issue with clamp placement is noted, showing some reflection on process accuracy.

To lift the grade to a more secure Achieved, the evidence could provide clearer detail about machine setup and calibration procedures, for example, describing how the zeroing process was carried out, how feed and spindle settings were determined, or how material alignment was confirmed. Strengthening the evidence through measurements or checks that show depth, position, and inlay fit corresponding to the VCarve design would also improve the robustness of the sample.

Finally, the evaluation could be improved by explaining why issues occurred and outlining how they would be addressed in future iterations, rather than simply stating what happened. This additional depth would solidify the evidence at Achieved and better demonstrate understanding of CNC process control.

For Achieved, the student needs to implement complex procedures to make a specified product using a Computer Numerical Controlled (CNC) machine.

This involves:

• integrating the limits of a CNC machine into a graphic representation of the desired product in a computer design setting that demonstrates an understanding of CNC programming language
• setting up and calibrating a CNC machine to software and manufacturer requirements
• operating a CNC machine to make a product in compliance with relevant health and safety regulations
• evaluating a CNC machine-made product against its graphic representation.

There are partial indications of understanding in each area, placing the work at high Not Achieved, but the depth, technical proficiency, and completeness required for Achievement are not present.

The workflow evidence demonstrates that an image was imported, vectors were traced, the board was sized, and a toolpath was selected in Aspire. However, the evidence does not demonstrate understanding of CNC limitations such as toolpath strategy, cut‑depth decisions, the constraints created by tool diameter and line width, expected material behaviour, or machine bed limitations. These omissions mean that the requirement to integrate machine and material limits into the graphic representation is not met.

CNC setup is present, and the description of zeroing X, Y, and Z using the paper method and positioning the bit shows the procedure occurred, but it remains descriptive only. There is no explanation of why the chosen zeroing method was appropriate, how accuracy was ensured, or how feed or spindle settings were confirmed, elements that are required to demonstrate correct and justified setup.

Safety is referenced only implicitly, with no explicit health and safety evidence provided. Achievement requires clear demonstration that the CNC machine was operated in compliance with health and safety regulations. The absence of identifiable hazard controls constitutes a significant gap in the evidence.

The evaluation states that the final product “looks exactly like the graphic design,” but no visual or measured evidence is provided to support this claim. There are no comparisons between the cut outcome and the Aspire (graphic representation) model, no measurements of depth or positional accuracy, and no commentary on quality indicators such as edge finish or tool marks. The evaluation is reflective but does not evaluate accuracy against the graphic representation, which is necessary for Achievement.

To lift the work to Achieved, the evidence needs to explicitly show compliance with health and safety expectations during CNC operation. A clearer explanation of how the final cut aligns with the Aspire model (photos, measurements, or specific commentary) would also be required.

Additionally, a brief justification of CNC choices such as toolpath selection, tool bit choice, zeroing method, and feed/spindle settings would help demonstrate the level of understanding needed to meet the standard.