AM System Construction

AM System Specifications

• When evaluating extrusion-based additive manufacturing (AM) systems, there are several key system specifications that are important to consider. Here is a list of critical specifications:

  • Build Volume/Work Envelope: This refers to the maximum size of the part that can be printed. It is one of the primary considerations, as it must be adequate for the intended objects to be manufactured.

  • Layer Resolution: Indicates the height of each layer, which affects the surface finish and detail of the printed parts. Lower layer heights can produce smoother surfaces and more detailed features.

  • Extruder Characteristics: This includes the number of extruders, the maximum extrusion temperature, and the nozzle diameter, which together affect the types of materials that can be used and the minimum feature size of the print.

  • Print Speed/Cubic Deposition Rate: The speed at which the printer can extrude material is critical for determining how quickly parts can be produced. This is often measured in millimeters per second (mm/s) or cubic millimeters per hour (mm³/h).

  • Material Compatibility: Different printers support different materials, so it’s important to ensure that the system can handle the specific plastics, composites, or other materials needed for your applications.

  • Positioning Precision: The accuracy with which the printer can position the extruder affects the dimensional accuracy and surface finish of the printed parts.

  • Heated Bed: The ability to heat the bed is important for printing with certain types of materials as it can prevent warping and improve bed adhesion.

  • Bed Leveling: Whether the bed leveling is manual or automatic can affect the ease of use and the time needed to prepare the printer for a job.

  • Connectivity, Control, & Compatibility: How the printer is controlled, whether through a USB connection, SD card, Wi-Fi, or other interfaces, can impact its convenience and integration into existing workflows, including whether or not the the type of slicer and printer control software the system is compatible with can affect the print preparation process and the features available to the user.

  • Reliability and Maintenance: The robustness of the system and the frequency of required maintenance are practical considerations for overall uptime and operational costs.

  • Safety Features: This includes aspects like enclosed build chambers, fume extraction, and automatic shutdown in the event of a problem.

• These specifications are critical to match the printer with the intended use-case scenarios. For industrial applications, reliability, speed, and material compatibility might be prioritized, while for prototyping studios, resolution and build volume could be more important. Understanding the trade-offs and how they align with your requirements is essential when selecting an extrusion-based AM system.

Calibration & Tuning of AM Extrusion Systems

• The precision of extrusion-based AM systems hinges on their proper calibration and tuning. These processes ensure that every aspect of the printing system operates within the specified parameters to achieve the desired accuracy, surface finish, and mechanical properties.

  • Print Tests and Diagnostics:

    • Benchmarks and Prototypes: Utilizes specific test patterns to evaluate and fine-tune print accuracy, speed, and material flow.

    • Results Analysis: Guides the interpretation of test prints to diagnose and correct issues with extrusion, accuracy, or surface finish.

  • Mechanical Calibration:

    • Frame Alignment: Checks for perpendicularity and parallelism in the printer’s structure.

    • Axis Calibration: Involves setting the correct movement distances for the X, Y, and Z axes, ensuring that the motions are true to the intended dimensions.

  • Extruder Calibration:

    • E-Steps Tuning: Refines the stepper motor settings to accurately extrude the correct volume of filament.

    • Nozzle Calibration: Adjusts the height and balance of the nozzle to achieve an even first layer, essential for adhesion and print quality.

  • Temperature Control:

    • PID Tuning: Establishes stable temperature control for the extruder and heated bed, crucial for consistent material flow and layer adhesion.

  • Software and Firmware Calibration:

    • Slicer Configuration: Tailors the software settings to the machine's capabilities for optimal print quality and speed.

    • Firmware Updates: Ensures the printer’s onboard software is finely tuned and up-to-date, affecting features like thermal runaway protection and auto bed leveling.

  • Routine, Preventative Maintenance:

    • Regular Check-ups: Outlines the schedule for checking and re-calibrating essential components to maintain optimal performance.

    • Problem Resolution: Provides a troubleshooting guide for addressing common calibration-related problems.