Disc 400
A flat round stepping target cut from 18 mm plywood. One part with no handles or hardware; lay the discs out on the floor in any pattern.
Interactive 3D model
Fabrication
Cut the disc with a router on a trammel, on a CNC from the DXF (one circle on layer CUT, centred on the origin) or with a jigsaw along a marked circle, then sand the edge. No chamfer is modelled; file a 2 × 2 mm chamfer by hand if wanted and sand the top face.
A thin disc slides on a smooth gym floor: protect the underside with a rubber pad or anti-slip coating. Use birch plywood and seal the edges.
Layout on a 1525 × 1525 mm sheet with a 4 mm kerf, one diameter per sheet in a square grid: Ø100 14 × 14 (196 pcs), Ø200 7 × 7 (49 pcs), Ø300 5 × 5 (25 pcs, only 4.5 mm edge margin), Ø400 3 × 3 (9 pcs), Ø500 3 × 3 (9 pcs, 8.5 mm margin). Where the margin is tight, cut one disc fewer per row with a jigsaw.
The 400 + 4 × 300 step uses the same discs: a Ø400 base and four Ø300 discs. Other stacks and columns are not modelled yet.
Geometry draft, not a tested sports apparatus. An 18 mm disc is a low jumping target; it is not designed as a landing platform for large drops and has not been tested for slip. Check the plywood, the edges and the floor surface before training.
