Creating Your First Slicable Device

Prev: Part 10: Designing Custom Subcomponents

In this step, you will create a device (not just a component), attach slicing settings, and prepare it for the slicer. By the end, you will have a device that is ready to slice and export in Part 12.

Why this step matters

PyMFCAD distinguishes between components (reusable building blocks) and devices (printable assemblies tied to a specific printer/light engine). Slicing requires device-level information such as pixel size, pixel count, layer height, and exposure settings. This step bridges design and fabrication.

What you will build

You will:

  1. Create a device sized for your printer.
  2. Add labels and a minimal bulk/void pair.
  3. Define slicer settings (printer, resin, default position/exposure).
  4. Save settings to JSON and re-load them (optional, but recommended).
  5. Preview the device to visually verify it before slicing.

If you already have a component from earlier steps, you can skip the geometry portion and focus on the device + settings sections.

Step 1 — Create a device (printer-aware)

Devices encode the printer geometry (pixel count, pixel size, layer size). For a Visitech LRS10-based printer you can use the built-in device classmethod:

from pymfcad import Device

device = Device.with_visitech_1x(
    name="MyFirstDevice",
    position=(0, 0, 0),
    layers=200,          # total layer count
    layer_size=0.01,     # mm per layer
)

Checkpoint: You should now have a device object that represents your printable build volume.

Step 2 — Add labels, voids, and bulk

Slicable devices still follow the void-in-bulk model. You need at least one bulk shape and one void shape to see meaningful output.

from pymfcad import Color, Cube

device.add_label("bulk", Color.from_name("gray", 127))
device.add_label("fluidic", Color.from_name("aqua", 127))

# A simple fluidic void (channel)
channel = Cube((50, 10, 6))
channel.translate((20, 45, 20))
device.add_void("main_channel", channel, label="fluidic")

# Bulk block (must be added last)
bulk_cube = Cube(device._size, center=False)
bulk_cube.translate(device._position)
device.add_bulk("bulk", bulk_cube, label="bulk")

Checkpoint: If you call device.preview(), you should see a single rectangular channel cut through a solid block.

Step 3 — Define slicer settings

Settings define the printer, resin, and default exposure/position behavior. Start with a minimal, explicit configuration. You can store settings to JSON so they can be reused by different devices.

from pymfcad import (
    Settings,
    ResinType,
    Printer,
    LightEngine,
    PositionSettings,
    ExposureSettings,
)

settings = Settings(
    printer=Printer(
        name="HR3v3",
        light_engines=[
            LightEngine(px_size=0.0076, px_count=(2560, 1600), wavelengths=[365])
        ],
    ),
    resin=ResinType(bulk_exposure=300.0, exposure_offset=0.0),
    default_position_settings=PositionSettings(),
    default_exposure_settings=ExposureSettings(),
)

settings.save("settings.json")
settings = Settings.from_file("settings.json")

Checkpoint: You should now have a settings.json file in your working directory.

Settings objects (what they are and when to change them)

Think of Settings as the print recipe for the entire device. It contains printer hardware details, resin chemistry metadata, and default motion/exposure values applied to every layer unless overridden later.

Settings

Container that bundles everything needed by the slicer.

  • You set it once per print (or per device family).
  • It stores printer, resin, and default layer behavior.
  • It can be saved/loaded from JSON for repeatability.

Printer

Describes the hardware platform (name + available light engines).

  • The slicer uses this to validate geometry and pick the right light engine.
  • If your printer has multiple light engines, list them all here.
  • It can be saved/loaded from JSON for repeatability.

LightEngine

Describes the optics that define pixel resolution.

  • name links the link engine to the actual printer. It must be the same as the light engine name in the printer hardware config.
  • px_size and px_count set the physical resolution.
  • wavelengths is used to match the resin exposure wavelength.
  • If your device size doesn’t match your light engine resolution, slicing will fail.

ResinType

Metadata used for traceability and consistent settings across experiments.

  • Tracks monomers, absorbers, initiators, and additives as percentages.
  • bulk_exposure sets the base exposure time (ms) required for bulk polymerization.
  • exposure_offset is an optional offset (ms) before polymerization begins. Used to adjust for polymerization delay from oxygen inhibition or other added inhibitors.
  • These values are saved into the settings JSON and exported with the print file.

PositionSettings

Controls motion behavior between layers (lift, speeds, waits, squeeze).

  • Think of this as the mechanical side of the print.
  • Use defaults unless you have a known motion profile to apply.

ExposureSettings

Controls light exposure behavior per layer (multiplier, power, wavelength).

  • This is where you tune curing behavior.
  • Use defaults first; adjust only after test prints.
  • Actual exposure time is computed as \((bulk\_exposure - exposure\_offset) * multiplier + exposure\_offset\).

Step 3b — Device-level defaults (global print behavior)

In addition to Settings, you can attach device/component-level defaults that the slicer will apply to every layer unless you later specify regional overrides (covered in Part 14).

from pymfcad import ExposureSettings, PositionSettings

# Apply defaults to the whole device
device.add_default_exposure_settings(
    ExposureSettings(bulk_exposure_multiplier=1.0, power_setting=100)
)
device.add_default_position_settings(
    PositionSettings(distance_up=1.0, up_speed=25.0, down_speed=20.0)
)

# Optional: burn-in layers in ms (longer exposures at the start)
device.set_burn_in_exposure([10000.0, 5000.0, 2500.0])

Checkpoint: If you later inspect the slicer output, the first three layers should use the burn-in exposure values above.

Step 4 — Preview your device before slicing

Always preview the device to confirm:

  • The channel is inside the bulk
  • Labels are correct
  • Nothing is missing or inverted
device.preview()

Checkpoint: In the visualizer, the Device view should show a solid block with the channel removed.

What’s next

In Part 12, you will run the slicer using the device and settings you created here, and generate a print file you can inspect.

Next: Part 12: Slicing Process