⊞ THRESHOLD RAMP GEN

OpenSCAD · 3D-Printable · Wheelchair Access v1.3.0 · Salvage Garden · CC-BY-SA

Slope / Ratio

4.8°

Angle

1 : 12

Rise : Run

Grade

Slope ratio (1 : N)

12 × rise

Meets the 1:12 minimum wheelchair slope limit at about 4.76°. Use 1:20 where space allows.

Dimensions

Step Height

110 mm

Track Width (one wheel path)

200 mm

Ramp Length (slope depth, auto-syncs)

1320 mm

Options

End-cap Ellipse Factor

1.0

Clearance (fit gap)

0.25 mm

Connector Type

Part to Render

Mouse Ears (anti-warp)

Include mouse ears when printing single part

Live Preview

Isometric view

Top view · print section cuts

Cross-section · print section cuts

About This Tool

This generator creates printable OpenSCAD threshold ramp sections for wheelchair access. It is intended for a paired-track ramp: print one track for the left wheelchair wheel and one matching track for the right wheel, then position the two tracks at the wheelchair's wheel spacing. The track width controls the printable path for one wheel, while the ramp length controls the slope depth over the threshold.

It starts from a 1:12 minimum ramp length, keeps each ramp-length print section within a 250 mm build area, and exports parts that use interlocking geometry for assembly. The connector can be the original integrated knob-and-notch, or a separate double-sided dovetail key that keeps the printable ramp sections smaller because the connector is printed as its own part.

The parametric ramp geometry is based on Customizable Threshold Ramps by the original Thingiverse author, published 22 Sep 2025: thing:7155319. This page adapts those OpenSCAD parameters into an interactive paired wheelchair track-ramp planning tool.

Wheelchair vs. Robot Vacuum

The original design targeted robot vacuum cleaners crossing low door thresholds (~7–8 mm). This tool adapts the same geometry into paired wheelchair wheel tracks for higher threshold access (~50–120 mm).

Parameter	Robot Vacuum	Wheelchair
Height	7–10 mm	50–120 mm
Load	~4 kg	150–250 kg
Slope ratio	Any	≤ 1:12 (ADA)
Segments needed	1–2	3–15+
Interlocking design	✓ shared
Parametric OpenSCAD	✓ shared
Multi-segment assembly	✓ shared
Print material	PLA fine	PETG / ASA rec.

Printing Guidance

For wheelchair loads use PETG or ASA with ≥ 40% infill and 3+ perimeters. Each ramp-length print section is kept to 250 mm or less. Print two matching tracks for a wheelchair, one per side, and align them to the chair's wheel spacing before use.

Segment assembly: Use the integrated knob-and-notch joins, or select the separate double-sided dovetail key when you want smaller ramp-section footprints on the print bed. For outdoor / wet areas apply a bead of silicone under each segment to prevent movement.

Safety note: Printed ramps are assistive aids. Always have a second person assist during initial use. For permanent installs, consult a certified accessibility contractor.