damiavicens/wilson-us-open-pro-100

Wilson US Open Pro 100 (WR198110U) — parametric 3D reconstruction

A watertight, part-segmented 3D model of a tennis racket, rebuilt from calibrated photographs and published specifications by a parametric Blender script rather than sculpted by hand. Ships with the full build source, the validation record, and per-part render sheets.

Not affiliated with, endorsed by, or produced by Wilson Sporting Goods. "Wilson" and "US Open" are trademarks of their respective owners; the name identifies the object that was measured.

What is in here

Path	What it is
wilson_us_open_pro_100.blend	Blender scene, 119 leaf objects in a named hierarchy
wilson_us_open_pro_100.obj / .mtl	Exported mesh, metres, resting at z = 0
wr_build.py, wr_lib.py, wr_all.py	The parametric builder — regenerates the whole model
wr_render.py, wr_explode.py, wr_pbr.py	Render, exploded-view and material passes
wr_validate.py, wr_gaps.py, wr_joints.py	The gate checks reported below
manifest.json	Parameters, per-leaf bounding boxes, gates, sanity checks
containment_tree.json	Part hierarchy with containment budgets
renders/	Contact sheets per part (_parts, _material, _real), ~2 GB
references/	Calibrated reference views, measurement JSONs, 4 US patents
wr_explode_1600.gif / .webp	Turntable + exploded-view animation, 90 frames

Geometry

• 119 leaf parts, 297,024 triangles
• Envelope 267.36 × 685.52 × 43.0 mm
• String bed: 16 mains × 19 crosses, 1.3 mm gauge
• Build frame: long axis +Y, string-bed normal +Z, string plane at z = 0, butt at y = 0. Every measurement and bounding box in manifest.json is a distance from the butt in this frame. The exported OBJ uses a separate delivery frame (centred on the footprint, resting at z = 0).

How well it matches the real racket

Silhouette overlay against a reference elevation calibrated at 0.375575 mm/px, measured at 17 stations along the frame:

	value	target
mean absolute error	0.356 mm	≤ 2 mm
max absolute error	1.34 mm	≤ 4 mm

Mass and inertia:

quantity	model	published	note
unstrung mass	270.11 g	270 g	derived, not a check — no wall thickness is published, so the wall was solved from this figure. The agreement is circular by construction.
strung mass	283.34 g	286 g	−0.93%; the string runs around the frame and the knots are not modelled, which is most of the shortfall
unstrung balance	325.4 mm	330 mm	independent — nothing was tuned to balance. Model is slightly head-light, implying the real frame carries relatively more laminate in the head than the uniform 1.00:1.29 hoop:throat wall ratio assumed here.
swingweight	381.6 kg·cm²	not published	reported for completeness

Three geometry gates pass: containment (0 manifold failures, 0 watertight failures), non-penetration between declared parts, and joint connectivity. Details in manifest.json under gates.

Known limitations

Stated in manifest.json rather than hidden:

• omitted_parts — string runs on the outer face between Double-Holes pairs terminate inside their barrel; about 2.5 g of string plus all knots are missing.
• material_gaps — the frame is a single isotropic CFRP, which cannot describe a laminate whose conductivity differs by orders of magnitude through thickness. Relevant if you use this for electromagnetic simulation.
• appearance — colours are median sRGB over masked regions of the calibrated front elevation. Presentation only; they carry no EM meaning.
• The 686 mm racket does not fold and does not fit a 444 × 324 × 104 mm envelope. Nothing has been scaled to make it fit.

Reproducing

The model is generated, not stored by hand — wr_build.py rebuilds it from the parameters in manifest.json. renders/ can be regenerated with wr_render.py.

Licensing note on references/

references/ contains third-party product photographs used as measurement input, and four US patent PDFs (US5037098A, US5158288A, US5368295A, US5993337A). The patents are US government publications. The photographs are included for reproducibility of the measurement and remain the property of their respective owners; they are not licensed under this repository's licence.