Mount Installation Templates for comma.ai devices

Mounting your comma device correctly the first time for best results.

Important

Disclaimer: These are NOT official comma.ai templates. This is a community-made project. Please direct all issues, suggestions, and feedback to the Issues tab of this repository.

This tool is inspired by Apple's Apple Watch band size tool for people who are too cool for straps with holes and Toyota's OEM Dashcam installation instructions.

• Users can check for correct sizing of generated PDFs with an outline of a credit or ID card.
• Users can see the list of PDFs in the Download Templates section below.
• We programmatically generate a PDF for each mount's footprint in commaai/hardware for comma three, comma 3x, and comma four.

Download Templates

All templates are standardized in Landscape orientation for maximum clarity and compatibility.

Universal templates are available as eleven paired clearance-offset variants for each mount: 45/75mm, 50/80mm, 55/85mm, 60/90mm, 65/95mm, 70/100mm, 75/105mm, 80/110mm, 85/115mm, 90/120mm, 95/125mm.

Universal Templates

Each paired page includes two mount footprints with one shared camera-housing reference line, so you can test a closer and deeper placement on one sheet.

comma four

• 45/75mm: US Letter | A4
• 50/80mm: US Letter | A4
• 55/85mm: US Letter | A4
• 60/90mm: US Letter | A4
• 65/95mm: US Letter | A4
• 70/100mm: US Letter | A4
• 75/105mm: US Letter | A4
• 80/110mm: US Letter | A4
• 85/115mm: US Letter | A4
• 90/120mm: US Letter | A4
• 95/125mm: US Letter | A4

comma 3x

• 45/75mm: US Letter | A4
• 50/80mm: US Letter | A4
• 55/85mm: US Letter | A4
• 60/90mm: US Letter | A4
• 65/95mm: US Letter | A4
• 70/100mm: US Letter | A4
• 75/105mm: US Letter | A4
• 80/110mm: US Letter | A4
• 85/115mm: US Letter | A4
• 90/120mm: US Letter | A4
• 95/125mm: US Letter | A4

comma three

• 45/75mm: US Letter | A4
• 50/80mm: US Letter | A4
• 55/85mm: US Letter | A4
• 60/90mm: US Letter | A4
• 65/95mm: US Letter | A4
• 70/100mm: US Letter | A4
• 75/105mm: US Letter | A4
• 80/110mm: US Letter | A4
• 85/115mm: US Letter | A4
• 90/120mm: US Letter | A4
• 95/125mm: US Letter | A4

Vehicle Specific Templates

These templates feature custom clearance zones (red dashed lines) derived from actual vehicle scans, offering precise alignment guides for specific car models.

Warning

Beta Feature: These templates are experimental and derived from user scans. Always double-check measurements before permanent installation.

Note

Want to help? We're looking for contributions to expand our vehicle-specific template library! Please submit a flatbed scanner scan of your car's ADAS camera cover (after removing it from the vehicle) along with a card-sized object for scale (e.g., gift card, library card, or any standard credit card-sized item). Share your scans or suggestions at Issue #6.

Toyota Corolla (2020)

Vehicle-specific Corolla templates are now available in five clearance-offset variants: 45mm, 50mm, 55mm, 60mm, 65mm.

comma four

• 45mm: US Letter | A4
• 50mm: US Letter | A4
• 55mm: US Letter | A4
• 60mm: US Letter | A4
• 65mm: US Letter | A4

comma 3x

• 45mm: US Letter | A4
• 50mm: US Letter | A4
• 55mm: US Letter | A4
• 60mm: US Letter | A4
• 65mm: US Letter | A4

comma three

• 45mm: US Letter | A4
• 50mm: US Letter | A4
• 55mm: US Letter | A4
• 60mm: US Letter | A4
• 65mm: US Letter | A4

How to Use

This project generates PDF mount installation templates to help mount comma hardware correctly.

1. Printing

• Print at 100% Scale: Ensure that "Scale to Fit" or "Shrink to Fit" is disabled in your printer settings.
• Paper Size: Templates are available for both US Letter and A4 paper sizes.
• Choose Paired Offset: Start with 45/75 (recommended), then move up through 50/80, 55/85, 60/90, 65/95, 70/100, 75/105, 80/110, 85/115, 90/120, or 95/125 if needed.

2. Verify Scale

• Place a standard credit card or ID card in the marked box at the bottom of the page.
• If the card fits exactly within the box, the scale is correct. If it doesn't fit, do not use the template.

3. Installation & Positioning

• For official install steps and cable routing guidance, use the comma.ai setup guide.
• Recommended Method (Outside Taping): Tape the template to the outside of the windshield! This makes it much easier to align with the camera/mirror from the inside without the paper getting in the way of your level or tape measure. Since you can't see the other side, you may want to have a very bright light source inside the car to see the template or a helper.
• Alternative Method (Cutting): If taping to the outside doesn't work for you, you can cut the template however you see fit. Usually, cutting around the mount footprint and leaving the clearance arcs intact is best.
• Clearance Zone: The red dashed arcs indicate the required clearance from the top of the mount to the vehicle's original camera housing.
• The camera housing should be outside (above) the curved arcs for an unobstructed view. Arcs range from 300mm to 1000mm.
• Mark the corners on the glass (e.g., with a dry-erase marker) or use painters tape to temporarily hold the template in place.
• Follow standard comma.ai instructions to attach the mount using the provided adhesive.

Technical Details

Build Pipeline

The PDF generation process is automated using make.

1. Source: Mount models (.stl) are sourced from the commaai/hardware submodule.
2. Orientation: The tools/orient_stl.py Python script loads each STL and rotates it to align the mounting surface with the XY plane (flat).
3. Projection: openscad is invoked with tools/project_mount.scad to project the very bottom of the 3D geometry onto a 2D plane, exporting the footprint as an SVG.
4. Composition: typst compiles template.typ, which combines the generated SVG footprint with:
   • A credit card outline for scale validation.
   • Clearance zone markings.
   • Title and instructional text.

AI / Computer Vision Workflow

An experimental workflow exists to trace vehicle features (like camera covers) from scans using Gemini and OpenCV. The entire pipeline is automated via make.

1. Preparation: Place a scan of the car's ADAS camera cover (after removing it from the vehicle) with a card-sized object for scale (e.g., gift card, library card, or any standard credit card-sized item) in vehicles/<vehicle_name>/raw/scan.png.
2. Annotate: Run make annotate-<vehicle_name> (e.g. make annotate-2020_corolla) to trigger the AI annotation. tools/vehicle_specific/annotate_scan.py uses gemini-3-pro-image-preview to highlight features (Magenta) and scale cards (Cyan), saving to vehicles/<vehicle_name>/ai/annotated_scan.png.
3. Process: tools/vehicle_specific/process_annotation.py extracts the scale (pixels/mm) and the raw trace from the annotated image to vehicles/<vehicle_name>/gen/raw_trace.svg.
4. Refine: tools/vehicle_specific/refine_trace.py rotates, centers, and symmetrizes the trace for engineering use, saving to vehicles/<vehicle_name>/gen/trace.svg.
5. Offsets: tools/vehicle_specific/generate_offsets.py adds clearance lines and the centerline, creating the final vehicles/<vehicle_name>/gen/offsets.svg used in the template.
6. Verify: make verify runs tools/verify_build.py, which uses gemini-3-flash-preview to visually inspect all generated PDFs/PNGs. It checks for the presence of red clearance lines, correct labels, and legible text, failing the build if any template is suspect.

Specifications

• Fonts: Uses DejaVu Sans Mono.
• Clearance Zones: Dashed red arcs indicate required clearance radii (default universal templates use 500mm to 1000mm).
• Clearance Offsets:
  • Universal templates: 45/75mm, 50/80mm, 55/85mm, 60/90mm, 65/95mm, 70/100mm, 75/105mm, 80/110mm, 85/115mm, 90/120mm, 95/125mm variants for each mount (comma three, comma 3x, comma four).
  • Vehicle-specific templates may use different offsets derived from the scan/trace workflow.

Tools Required

To build the templates locally, you will need:

• OpenSCAD (headless support required)
• Typst
• Python 3 with numpy-stl, though uv is used to manage dependencies.
• Make

Those tools can be found in package managers such as brew on macOS, apt on Debian/Ubuntu, dnf on Fedora, etc.

Adhesive Cutting Templates

Here are 3D printable STL files that can serve as cutting guides for mount adhesives. These are particularly useful if you are replacing the 3M VHB adhesive and want a perfect fit for the mount's footprint.

Warning

Beta Feature: These templates are experimental. Always verify the fit with your mount before using them to cut adhesive.

• comma four: Standard (with islands) | Solid (no islands)
• comma 3x: Standard (with islands) | Solid (no islands)
• comma three: Standard

The standard templates for comma four and 3x include split horizontal bridges to support internal island guides (for the mount's own internal relief holes) while keeping the central area clear. The solid versions provide just the outer silhouette.

Similar Tools

• DML Tool - A 3D printed tool with additional added components such as a mini-level bubble tool to help make sure the mount is leveled on the windshield.