Test Geometry

Test Geometry creates sample bodies and paths for calibration prints. The shape is chosen from the dropdown on the component. Using the same shape for every run of a test series makes the measurements comparable.

Three families:

  • Free shapes - cylinder, vase, twisted vase, frustum, wall and box, sized from the component’s own inputs.
  • Standard specimens - flexural and compressive test bodies at the nominal dimensions of DIN EN and ASTM standards, so a printed batch can be tested against a published method instead of an ad-hoc block.
  • Extrusion test path - a zig-zag line for flow and cornering checks.

Panel: 6 Calibrate. Nickname: TestGeo. Compute button: no (runs on every change).

Inputs

Name Type Default Description
height Number 100 Overall sample height in mm
radius Number 40 Base radius, mm, for cylinder, vase and frustum

Optional group: Base-plane input

Right-click the component to switch this group on. The inputs appear only while the group is enabled.

Name Type Description
plane Plane Base plane (default World XY)

Optional group: Profile detail inputs (waves, twist, sides, frustum ratio)

Right-click the component to switch this group on. The inputs appear only while the group is enabled.

Name Type Default Description
waveAmp Number 0.15 Vase: radial wave amplitude as fraction of radius (0 = straight)
waveCount Number 3 Vase: number of radial waves over the height
twistDeg Number 90 Twisted vase: total twist over the height, deg
sides Integer 0 Vase or frustum section sides (0 to 2 = circle, 3 or more = polygon, twisted vase defaults to 6)
topRatio Number 0.6 Frustum: top radius divided by base radius

Optional group: Wall / box dimension inputs

Right-click the component to switch this group on. The inputs appear only while the group is enabled.

Name Type Default Description
length Number 150 Wall length or square box side length in mm
width Number 8 Wall thickness in mm (the box uses length for both sides)

Optional group: Standard specimen scale (DIN EN / ASTM shapes)

Right-click the component to switch this group on. The inputs appear only while the group is enabled.

Name Type Default Description
specimenScale Number 1 Uniform multiplier for standard specimen dimensions (1 = nominal size)

Optional group: Extrusion test path inputs (zig-zag line)

Right-click the component to switch this group on. The inputs appear only while the group is enabled.

Name Type Default Description
zzLength Number 150 Zigzag: length of one straight pass, mm
zzPitch Number 10 Zigzag: distance between passes, mm. Set it to the layer spacing you are testing
zzPasses Integer 8 Number of straight zigzag passes, at least 2
zzLayers Integer 1 Number of stacked zigzag layers, at least 1
zzLayerHeight Number 3 Vertical spacing between zigzag layers in mm, used when zzLayers exceeds 1
zzArcTurns Boolean true Use semicircular zigzag turns when true, or sharp reversals when false

Outputs

Name Type Description
geometry Brep Test geometry as a Brep. Wire into the slicer
sections Curve (list) Cross section curves used for the loft. Empty for box and wall
info Text Shape summary
path Curve (list) Zigzag toolpath in Rhino document units for G-code Generator (empty for solid shapes)

Standard specimens

Shape Standard Nominal size (mm) Test
BendingEN196 DIN EN 196-1 160 × 40 × 40, span 100 three-point bending of cement mortar; the broken halves are then crushed between 40 × 40 mm platens
BendingISO178 DIN EN ISO 178 80 × 10 × 4, span 64 three-point bending of plastics, 16:1 span-to-depth
BendingASTMD790 ASTM D790 127 × 12.7 × 3.2, span 51.2 three-point bending of plastics, 16:1 span-to-depth
CompressionEN12390Cube DIN EN 12390-1/-3 150 cube compressive strength of hardened concrete
CompressionEN12390Cylinder DIN EN 12390-1/-3 Ø150 × 300 compressive strength of hardened concrete
CompressionASTMD695 ASTM D695 12.7 × 12.7 × 25.4 compression of rigid plastics, loaded along the long axis

The shapes and tolerances of the concrete specimens are specified in EN 12390-1; EN 12390-3 is the compression test method. Both parts are named because you need the first to cast the body and the second to test it.

For a cement-based print, EN 196-1 is the closest fit: it is the reference method for cementitious binders, and the same prism gives you both the flexural and (from its halves) the compressive strength.

What the component does not claim

These are nominal geometries only. Nothing here asserts that a printed body is a valid specimen under the standard. Layer orientation, surface finish, curing and the anisotropy of an extruded part all sit outside the geometry, and every one of these standards was written for cast or moulded material. Use them to make a test series internally comparable and to talk to a testing lab in its own dimensions - not to claim conformity.

specimenScale exists because the plastics bars are unprintable at nominal size: an ISO 178 bar is 4 mm thick and an ASTM D790 bar 3.2 mm, both thinner than a single LDM layer. The component says so with a remark, and says again that a scaled body is no longer at the standard’s dimensions, so its results are comparable within your own series but not to the standard.

The zig-zag extrusion test

A boustrophedon line: straight passes joined alternately at each end, optionally stacked. It is a toolpath, not a solid, so geometry is empty on purpose and the line comes out of path. Wire that straight into G-code Generator; sending it through the slicer would try to section a curve.

The reversals are the point of the test. A straight line only shows steady-state flow; the turns show whether the layer tears on the inside of the corner and over-deposits on the outside. Rounded turns (zzArcTurns, a half circle of radius zzPitch/2) keep the tangent continuous and are the gentler case; sharp turns are the harsher one. Set zzPitch to the layer spacing you actually intend to print at, and the gaps or overlaps between passes tell you whether the flow matches the spacing.

Stacked layers alternate their start side, so a stack does not put its seam at the same end on every layer.

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