# HP-01 Hydroponic Plant Pot — Printing

Seven printed parts, all fit a Bambu Lab P1S (256 × 256 × 256 mm) and any
similar-or-larger FDM bed.

| STL | Material | Notes |
|---|---|---|
| `reservoir_body` | **PETG** | Holds nutrient solution — see the leak-tight settings below. |
| `lid` | PETG or PLA | Net-cup hole, probe wells, skirt. |
| `electronics_tower` | PETG or PLA | Dry electronics box. |
| `tower_cover` | PETG or PLA | Has the BH1750 sky window (Ø6 light bore + a Ø10 × 1.5 rebate on top for the clear sealing disc). |
| `grow_ring` | PLA / PETG (white/natural) | Reflective inner channel helps the grow light. |
| `window_bezel` | PETG or PLA | Clamps the sight window. |
| `net_cup` | (optional) PETG | Representative — a purchased 3-inch net cup is recommended. |

## The reservoir MUST be water-tight (print it like SP-01's reservoir)

The `reservoir_body` holds nutrient solution for weeks. Print it in **PETG** with
watertight settings:

- **Walls / perimeters: 4+** (≥ 1.6 mm shell). PETG bonds layer-to-layer well.
- **Bottom/top layers: 5+**, **infill ≥ 25 %** (the floor is a water floor).
- **Layer height ≤ 0.20 mm**, **flow calibrated** (over/under-extrusion is the
  usual leak cause).
- Nozzle 240–250 °C, bed 80 °C, **slow first layer**; enclosure/no draft.
- Print the reservoir **as oriented** (open top up) so the floor and side seams
  are continuous — no seams across the water floor.

**LEAK TEST — do this before planting, every unit:**
1. Fit the sight window (clear PETG sheet; optional Ø1 mm O-ring cord in the
   groove) and bolt the bezel down (4 × M3), then seal the sheet-to-rebate joint
   with a thin bead of aquarium silicone — the bead is the real seal. Let it cure
   fully (24 h).
2. Fit the Ø17 grommets in the pH + EC wells (or plug them).
3. Fill with plain water to the fill line (~135 mm) and stand it on a dry paper
   towel **overnight**. Any damp patch = a leak — reprint the reservoir with more
   perimeters / higher flow, or seal the offending seam with food-safe epoxy.
4. Empty, dry, then use.

If a wall weeps through the layers (not a seam), the shell is under-extruded —
raise perimeters/flow. A brush-coat of food-safe epoxy on the INSIDE is the
belt-and-braces fix.

## Wet / dry separation (built into the geometry — do not defeat it)

- The reservoir is a **sealed vessel**: 3 mm PETG on all four walls + floor. The
  only penetrations of the water-holding envelope are the **sight window**
  (bezel-clamped + siliconed) and the **open top** (covered by the
  lid, well above the water). The pH/EC wells are in the **lid**, above the
  water surface — never in a submerged wall seam.
- The **electronics tower is a physically separate box** bolted to the OUTSIDE
  of the reservoir's back wall. It shares no cavity with the reservoir; the
  reservoir's solid back wall + the tower's own front wall (6 mm of plastic)
  sit between the water and the Feather. A reservoir leak drains **down the
  outside**, never into the sealed tower.
- The sensor/LED cables enter the tower through a small **notch at the very top
  of the tower's own front wall** (well above the water line). It is a notch in
  the tower, not a hole in the reservoir — the reservoir's back wall stays fully
  solid, so wet/dry separation is preserved.
- Keep it that way: don't drill the reservoir walls, and don't route wet tubing
  through the tower.

## Supports & orientation

- `reservoir_body`, `electronics_tower`: print upright (open side up); the wells,
  bosses and the window rebate are self-supporting or need only minor supports at
  the window slot.
- `grow_ring`: print upright (channel up) — the pegs point down; no supports.
- `lid`: print top-up; the well spigots and skirt bridge fine.
- `tower_cover`, `window_bezel`, `net_cup`: flat, no supports.

Heat-set inserts are optional; all screws are self-tapping into the printed
pilot bores (M2 for the boards, M3 for the covers/bezel/tower).
