Lemon / Citrus Hand Squeezer — Reamer + Strainer Cap + Pour Spout

A two-piece manual citrus squeezer — print both parts, drop the
cap on the bowl, and you have a hand juicer with a strainer and a
pour spout.

How it works

• Cap = strainer disc + swirly helical reamer cone. The cone is a linear_extrude(twist, scale) of a cosine-wave star polygon, giving sharp helical ridges with a smooth wavy outer profile. Half a turn of twist from base to tip means as you twist a lemon-half onto the cone, the spirals shear the flesh and direct juice down the ridge channels.
• Strainer: a ring of 24 × Ø3 mm holes drilled straight through the cap's solid puck floor. No bridges, no supports — just a perforated disc.
• Bowl: 95 mm outer Ø × 50 mm tall cylindrical juice cup with a tapered U-trough pour spout punched through the rim. The trough's cavity floor is at the bowl's juice level so juice flows out the moment you tilt.
• Cap → bowl seat: the cap's outer lip is a full-height conical flare (Ø89 → Ø93 over 6 mm) that nests into a matching chamfer at the bowl rim. Slope-matched 1:1 so the cap seats face-to-face along the entire lip, not on a knife-edge inner corner. Slight interference at the bead lets the cap stow upside-down INSIDE the bowl when not in use — a press-fit storage trick.
• Lemon-peel dimple texture on the bowl's outer wall (skipped in the spout sector so the trough stays smooth).

Parts & files

No supports needed for either part. The cone tip at top is the
print-finish point; no overhangs > 45° anywhere.

Printing

• 0.2 mm layers, 3 walls, 15 % infill is plenty (the bowl is mostly hollow, the cap is mostly cone).
• Yellow PLA is the obvious aesthetic choice — looks like a lemon. Any food-contact PLA grade works for short use; rinse + hand-dry between uses (FDM layer lines are not dishwasher-safe and trap residue if soaked).
• Print both parts at once on a 220 × 220 bed; total weight ≈ 50 g.

Use

1. Cut a lemon (or lime / small orange) in half.
2. Drop the cap onto the bowl rim.
3. Cut-side down on the cone, twist + press hard.
4. Juice flows through the ridges, through the strainer holes, into the bowl. Pulp + seeds stay on top of the cap.
5. Lift the cap off, pour from the bowl spout.
6. Rinse both parts, snap the cap upside-down into the bowl for storage.

Tweaking the SCAD

The OpenSCAD source is included. Useful knobs at the top:

• bowl_outer_d (95 mm) — bowl diameter; scale up for grapefruit halves, down for limes.
• bowl_h (50 mm) — juice volume.
• cap_cone_h / cap_cone_d_base — reamer aggression; taller cone
  • bigger base = more juice extraction per twist.
• n_strainer (24) / strainer_hole_d (3 mm) — strainer hole count
  • size.
• spout_proj (24 mm) — how far the pour spout projects past the bowl wall.

The part switch at the top of the SCAD selects what to render —
"bowl", "cap", "all" (assembled), "exploded", or "section"
(half-cut for inspecting the cap-bowl seat).