VacDrain Reducer V1 – Shop-Vac Hose to 3/4" A/C Drain Adapter

                                   Summary / Description

This is a custom shop-vac to A/C drain adapter designed to help clear clogged condensate drain lines using a vacuum.

One end is sized so a shop-vac hose slips over it snugly

The other end is a male spigot that inserts into a standard US 3/4" PVC A/C drain coupler

The body uses a smooth external taper to handle PVC tolerances and improve grip

Internal air path is continuous and tapered for good airflow with no suction lock

This model was fit-tested and tuned for real-world PVC drain fittings and prints cleanly as a single solid part.

                                   Features

One-piece, manifold design

Hose-over → pipe-insert (female-to-male functionally)

Long taper to accommodate pipe variation

Optional hose stop ridge

Embossed size and direction label

No supports required

                    Print Settings (Recommended)

Material: PLA+ (PETG also works)

Layer height: 0.2–0.28 mm

Walls: 7–8 (walls matter more than infill)

Infill: 0–5%

Seam: Aligned

Supports: None

Raft: No

Orientation: Print upright as modeled

⚠️ Make sure Horizontal Expansion / XY compensation = 0.00 in your slicer for an accurate fit.

                                 Fit Notes

The A/C drain side was tuned to ~26.7 mm OD, which provided a slightly snug, hands-free fit in a standard US 3/4" PVC coupler

PVC fittings vary by manufacturer — if needed, adjust the AC spigot OD slightly (±0.1 mm) in OpenSCAD

Let the print cool fully before test fitting

                               Use Case

Ideal for:

Clearing A/C condensate drain clogs

Preventive drain maintenance

Temporary or reusable vacuum hookups (no tape required)

                                  Customization

The OpenSCAD file is fully parametric:

Adjust hose size

Adjust pipe OD

Change taper length

Modify wall thickness

Enable/disable embossed label

                                      Disclaimer

Use at your own risk. This is a non-pressurized vacuum accessory. Do not use with high heat or solvents.