Snap-Fit Sensor Enclosure CAD Design
Budget: ₹1,500 – ₹12,500 INR
Design Brief — 3-Part Snap-Fit Sensor Enclosure
Overview
We need a CAD-ready design for a small, square, dome-topped electronics enclosure (think AirTag-meets-sensor styling). The enclosure is a three-part stack that snap-fits together with no visible screws on the outside, houses a small PCB, and runs on a single CR2 battery accessible from the rear via a snap-fit cover.
Known dimensions
Outer footprint: 55 × 55 mm, square with generously rounded corners (corner radius ~6–8 mm to match the reference photos).
Dome aperture / dome base diameter: ~49–50 mm circular.
Overall height (Z): 25mm
The three components
Top — acrylic dome cover (circular). Spherical-cap dome that drops into the circular aperture of the mid layer and retains via snap. Preferred method is a continuous annular snap bead on the dome's cylindrical skirt engaging a matching internal groove in the mid-layer aperture wall, you can propose best possible way to do this.
Mid layer — main housing. The square "box" body: top face with the circular cutout, four side walls, rounded corners. Carries the dome retention feature on top and mates to the bottom plate below (perimeter snap join).
Bottom layer — base / battery plate. Two jobs: (a) retain the PCB via snap clips or screw bosses, and (b) integrate a CR2 battery holder (battery is ⌀15.6 × 27 mm, 3 V) with sprung and flat contacts, closed by a snap-fit access cover with a finger recess for tool-free swaps.
Material recommendations
Housing (mid + bottom): ABS or PC/ABS, matte white, ~2.0–2.5 mm nominal wall, uniform thickness, proper draft (≥1° on all walls).
Dome: IR-transmissive HDPE
Mechanical requirements
All three parts snap together; no external fasteners visible.
Design snap features (cantilever or annular) with correct undercut, lead-in/retention angles, and deflection within material strain limits for repeated use on the battery cover.
Include living tolerances / clearances between dome and aperture for assembly without forcing.
Add ribs/bosses as needed for stiffness and PCB standoff.
Open questions / inputs we'll provide
Target manufacturing process: The drawing is for final volume production and assembly so those considerations should be present, also the same would be used for the proto building with 3d printing.
Deliverables expected
Parametric 3D CAD (STEP + native format + format for the 3D printing ) of all three parts plus an assembly file.
Snap-fit feature detail and a recommended fit/tolerance scheme.
A short DFM note (draft, wall thickness, gate/ejection suggestions)
Exploded view and basic assembly instructions.
Overview
We need a CAD-ready design for a small, square, dome-topped electronics enclosure (think AirTag-meets-sensor styling). The enclosure is a three-part stack that snap-fits together with no visible screws on the outside, houses a small PCB, and runs on a single CR2 battery accessible from the rear via a snap-fit cover.
Known dimensions
Outer footprint: 55 × 55 mm, square with generously rounded corners (corner radius ~6–8 mm to match the reference photos).
Dome aperture / dome base diameter: ~49–50 mm circular.
Overall height (Z): 25mm
The three components
Top — acrylic dome cover (circular). Spherical-cap dome that drops into the circular aperture of the mid layer and retains via snap. Preferred method is a continuous annular snap bead on the dome's cylindrical skirt engaging a matching internal groove in the mid-layer aperture wall, you can propose best possible way to do this.
Mid layer — main housing. The square "box" body: top face with the circular cutout, four side walls, rounded corners. Carries the dome retention feature on top and mates to the bottom plate below (perimeter snap join).
Bottom layer — base / battery plate. Two jobs: (a) retain the PCB via snap clips or screw bosses, and (b) integrate a CR2 battery holder (battery is ⌀15.6 × 27 mm, 3 V) with sprung and flat contacts, closed by a snap-fit access cover with a finger recess for tool-free swaps.
Material recommendations
Housing (mid + bottom): ABS or PC/ABS, matte white, ~2.0–2.5 mm nominal wall, uniform thickness, proper draft (≥1° on all walls).
Dome: IR-transmissive HDPE
Mechanical requirements
All three parts snap together; no external fasteners visible.
Design snap features (cantilever or annular) with correct undercut, lead-in/retention angles, and deflection within material strain limits for repeated use on the battery cover.
Include living tolerances / clearances between dome and aperture for assembly without forcing.
Add ribs/bosses as needed for stiffness and PCB standoff.
Open questions / inputs we'll provide
Target manufacturing process: The drawing is for final volume production and assembly so those considerations should be present, also the same would be used for the proto building with 3d printing.
Deliverables expected
Parametric 3D CAD (STEP + native format + format for the 3D printing ) of all three parts plus an assembly file.
Snap-fit feature detail and a recommended fit/tolerance scheme.
A short DFM note (draft, wall thickness, gate/ejection suggestions)
Exploded view and basic assembly instructions.