Week 05

Group Assignment Requirements

• Test the design rules for your 3D printer(s).
• Characterize dimensional accuracy, tolerances, and mechanical limits.
• Document the results on the group page.
• Reflect individually on the characteristics of the printer(s).

Learning Outcomes

• Understand additive manufacturing constraints.
• Evaluate overhang, bridging, and support limitations.
• Measure dimensional accuracy and tolerance behavior.
• Interpret how slicing parameters influence print quality.

1. Identification of the 3D Printers

For this group assignment, two FDM 3D printers were used to evaluate and test design rules. The primary technical difference between them was the nozzle diameter (0.8 mm vs 0.4 mm), which directly influences dimensional accuracy, detail resolution, and extrusion behavior.

Printer 1 – Elegoo Neptune 4 Max

• Nozzle: 0.8 mm
• Filament: PLA 1.75 mm
• Leveling: Automatic mesh leveling
• Build Surface: Magnetic removable plate

The 0.8 mm nozzle allows greater material flow and faster printing, but reduces fine detail resolution. This configuration favors large structural components.

Printer 2 – Creality Hi (Multicolor)

• Nozzle: 0.4 mm
• Filament: PLA 1.75 mm
• Multicolor System: 4-in-1 extrusion input
• Leveling: Automatic leveling

The 0.4 mm nozzle provides higher detail resolution, making it more suitable for tolerance testing and fine features.

OrcaSlicer Configuration – Elegoo Neptune 4 Max

OrcaSlicer was used to configure and prepare prints for the Elegoo printer. The official profile was imported to ensure accurate machine parameters.

Step 1 — GitHub Repository

Accessing the official OrcaSlicer repository.

Step 2 — Download for Windows

Downloading the correct version.

Step 3 — Main Interface

Initial software configuration.

Step 4 — Importing Configuration

Loading FabLab-specific parameters.

Step 5 — Configuration Successful

Machine ready for slicing.

Creality Print Configuration – Creality Hi

Creality Print was used to prepare slicing files for the multicolor Creality printer.

Step 1 — Download Page

Accessing Creality Print software.

Step 2 — Main Interface

Printer configuration and slicing preview.

2. Preparing the Printer – Elegoo Neptune 4 Max

Step 1 – Feeding the Filament Through the Sensor

The preparation process began by loading the PLA filament into the material detection system. The filament was passed through the filament sensor to ensure material presence detection during printing.

This step is important because the sensor prevents failed prints caused by filament depletion or breakage during long jobs.

Step 2 – Inserting PLA into the Extruder

After passing through the sensor, the filament was inserted into the direct-drive extruder system.

Proper insertion ensures consistent extrusion and avoids under-extrusion issues during the first layers.

At this stage, the extruder motor engages and feeds the filament into the hotend once the target temperature is reached.

Step 3 – Preheating Configuration

Using the printer’s control panel, the bed and nozzle were preheated according to PLA printing requirements.

Typical PLA settings:

• Nozzle temperature: ~200–220°C
• Bed temperature: ~50–60°C

Preheating stabilizes extrusion flow and improves first-layer adhesion, which is critical for dimensional accuracy in test models.

Step 4 – Printer Ready for Operation

Once temperatures stabilized and filament flow was verified, the machine was ready to begin the design rule test prints.

Ensuring proper mechanical preparation before printing reduces variability in experimental results and increases repeatability when evaluating dimensional accuracy and tolerances.

Printing Parameters & Technical Configuration

The comparison highlights how nozzle diameter directly influences extrusion width, minimum wall thickness, tolerance testing capability, and fine-detail reproduction. Even when maintaining identical layer heights, the 0.8 mm configuration imposes geometric constraints that affect design rule validation.

3. Design Rule Tests – Elegoo Neptune 4 Max (0.8 mm)

For this printer, four different tests were performed:

• Temperature calibration tower
• Geometric tolerance test (print-in-place hinges)
• Detail resolution test (“Millennium Falcon” model)
• Large-format functional print

Due to the large build volume of the Neptune 4 Max, most models were arranged in a single print job. However, before combining them, it was necessary to determine the optimal printing temperature using a temperature tower test.

1️⃣ Temperature Tower (190°C – 230°C, 5°C steps)

A temperature tower ranging from 190°C to 230°C in 5°C increments was printed to identify the optimal extrusion temperature for PLA.

Observed Results:

• Low temperatures (190–200°C): noticeable stringing and weaker layer adhesion.
• High temperatures (220–230°C): increased material flow and slight deformation in fine details.
• Optimal range: approximately 210–215°C, balancing adhesion and geometric stability.

This test demonstrated the trade-off between material fluidity and dimensional accuracy. The optimal performance was achieved at an intermediate temperature.

2️⃣ Tolerance Test – Print-in-Place Hinges

A hinge test model was printed with tolerances ranging from 0.1 mm to 0.45 mm in 0.05 mm increments.

Results:

• 0.1–0.25 mm: hinges completely fused.
• 0.3–0.35 mm: movement possible but with high friction.
• 0.4–0.45 mm: free movement and functional behavior.

With a 0.8 mm nozzle, the minimum functional tolerance was approximately 0.4 mm. This confirms that nozzle diameter directly influences mechanical clearances in print-in-place components.

3️⃣ Detail Test – “Millennium Falcon” Model

A detailed model similar to the traditional “benchy” was printed, but using a Millennium Falcon geometry to evaluate fine features.

Results:

• Supports were difficult to remove.
• Small details appeared coarse.
• Fine geometries lacked precision.

The 0.8 mm nozzle prioritizes structural strength and speed but reduces small-detail resolution.

4️⃣ Functional Print – “Rock Hand” Drumstick Holder

A large-format functional piece was printed to evaluate structural integrity and support behavior.

Results:

• Strong structural performance.
• Tree supports were easy to remove.
• Minor difficulty in narrow regions (between fingers).
• Good mechanical resistance.

The printer demonstrated superior performance for large functional components compared to small-detail models.

🐋 4. Test – Creality Hi (0.4 mm, Multicolor)

A multicolor whale model was printed using the Creality Hi printer. The objective was to evaluate detail resolution, surface finish, and color transition accuracy.

The model was printed using three filaments:

• White (lower section)
• Blue (main body)
• Black (eyes)

Printing time: approximately 3 hours.

Step 1 — Print Bed Preview

Model positioned in Creality Print before slicing.

Step 2 — Remote Monitoring

Live camera monitoring during printing.

Step 3 — Final Print (Top View)

Surface finish and detail resolution.

Step 4 — Final Print (Side View)

Clean color transitions and refined geometry.