stl-torture-test

Compact all-in-one 3D-printer / slicer calibration plate. One small STL packed with the widest possible spread of geometry so you can dial in speed, layer height, smoothing, retraction, cooling and support in a single print.

Pure-Python generator, zero dependencies. Binary STL, millimeters.

Files

File	What
torture_test.stl	Ready-to-slice plate — 9 970 triangles, ~487 KB
generate_torture_test.py	Generator. Edit sizes, rerun, get a new STL. Zero deps
render_previews.py	Renders the PNGs in previews/. Needs numpy
previews/	hero, front, right, top, and 2×2 preview.png

The plate

• Footprint 58 × 58 mm, 18.5 mm max height, 0.8 mm base.
• ~9.3 cm³ solid — roughly 5–6 g PLA at 15 % infill, ~1 h print. Uses as little plastic as the feature set allows.
• Every feature is a separate closed shell sunk 0.3 mm into the base plate; the slicer unions them automatically.

Features and what each one tests

Feature	Slicer parameter it exercises
Cube 10 mm	XYZ dimensional accuracy, top ironing
Staircase 2 / 4 / 6 / 8 mm	Layer registration, flat-top finish
Thin walls 0.4 / 0.8 / 1.2 mm	Perimeter width, minimum wall
Cone r4 h16 + pyramid	Sharp points, cooling, minimum layer time
Dome r6	Layer-height stepping on curvature (smoothing)
Torus R4.5 r2	Curved overhang all around, tangent bed contact
Vertical tubes, holes d3 / d6	Hole shrinkage
Block, horizontal hole d5	Circular overhang without support
Sphere d11 on r2.5 pedestal	Support settings — floating overhang all around
Bridge, 14 mm span	Bridging speed / fan
Two towers r1.5, 8 mm apart	Stringing, retraction, speed
Fins 30 / 45 / 60 / 70°	Support-free overhang limit
Cup, 1 mm wall, h12	Seam position, wall smoothness
45°-rotated pillar	Ringing / ghosting on diagonals

Print notes

• Slice once with supports off — sphere-on-pedestal, 60/70° fins and the horizontal hole show raw unsupported limits. Second run with supports on to compare.
• 60/70° fins lean out over bare bed on purpose; supports build from the bed, not the plate.
• Layer-height comparison: dome and staircase show the difference best.
• Speed / ringing: towers and the rotated pillar.
• Seam quality: the cup.

Regenerate

python3 generate_torture_test.py

Prints a per-part manifold + signed-volume check and an ASCII top view, then writes torture_test.stl. No external libraries needed.

Re-render previews

python3 render_previews.py

Software renderer (z-buffer, flat shading, 3× supersampled), PNG written with the stdlib. Only the preview step needs numpy; the STL generator stays dependency-free.