If you’re considering a custom case for your equipment, you’re thinking about safety in transit, ease of deployment on-site, and the longer service life of sensitive and/or costly instruments. A technical packaging partner can deliver all that and more. But the first step to achieving those goals starts with you.
A precise set of measurements, encompassing every aspect of your equipment, allows a technical packaging engineering team to properly assess your project, identify the right materials and construction approach, provide you with an accurate estimate, and, finally, a custom case that answers your unique needs.
What follows is a walk-through of every measurement and piece of information a technical packaging team will need to get started. It may seem detailed and demanding, but time spent now in carefully taking and recording these measurements will save even more time and expense down the road, facilitating the entire process from initial drawings to final delivery.
1. Start with the Right Measuring Tools
Accurate measurements require the right instruments. Before you begin, make sure you have:
- Digital calipers for precise component-level measurements to 0.01 mm. This is your most important tool.
- Steel ruler or straightedge for longer flat dimensions along panels and frames.
- Tape measure for total equipment footprint, rack-mount heights, or shipping pallet dimensions if relevant.
- Angle gauge or protractor if any part of your equipment has angled or non-rectangular surfaces.
- Feeler gauges for tight clearance gaps around connectors, fan grilles, or ventilation openings.
- Graph paper or a dimensioned sketch template to record and organize measurements consistently.
Never rely solely on a manufacturer’s published specifications. Real-world units frequently differ from spec-sheet dimensions by several millimeters due to manufacturing tolerances, firmware boards, or attached peripherals. Always measure the specific, physical unit you intend to encase.
2. Measure the Overall Equipment Envelope
This “envelope” is the total 3D bounding box of your equipment: the maximum height, width, and depth it occupies at any point. This is the foundational measurement that defines the minimum interior volume your custom case must provide. To measure the envelope correctly:
- Place the equipment on a flat, level surface.
- Measure maximum width (X-axis) at the widest point, including any protruding handles, side-mounted brackets, or external connectors.
- Measure maximum depth (Y-axis) from the frontmost to the rearmost point, including any rear-panel protrusions.
- Measure maximum height (Z-axis) from the base to the tallest point, including feet, lid hardware, or antenna mounts.
Record all three measurements and note where each maximum occurs (for example, “maximum width occurs at the front panel handle”). This context helps engineers understand the shape constraints driving each dimension.
You should also flag any known tight-clearance areas. For instance, if a component runs close to its maximum operating temperature, it will need adequate airflow spacing.
3. Document All Connectors, Ports, and Controls
Precisely locate and measure every port, connector, button, indicator, or ventilation opening that must remain accessible while the equipment is in its case. A technical packaging team will use this information to design panel cutouts, access doors, or window panels. For each accessible feature, measure and record:
- Height offset: distance from the bottom of the equipment to the center of the feature
- Horizontal offset: distance from the nearest reference edge (left or right) to the center of the feature
- Opening dimensions: the width and height of the port, button, or vent itself
- Plug clearance: if a cable or connector will be inserted during use, measure the depth and width clearance needed, especially for right-angle connectors or locking plugs
Organize these measurements by face (front panel, rear panel, left side, right side, and top as applicable). A dimensioned face diagram for each side is ideal and will directly inform panel cutout drawings.
Finally, wherever possible, take measurements with the cables or connectors physically installed. For example, a locking power connector or right-angle Ethernet cable can add 25-40 mm of required clearance depth beyond the panel face.
4. Identify and Measure All Mounting Points
If your equipment will be secured inside the case rather than resting freely, you’ll need to provide precise mounting point data. This will determine the appropriate internal structure, whether that’s a machined mounting plate, custom foam inserts, shock-isolated standoffs, or rack-mount hardware. For each mounting point, provide:
- Mounting hole diameter measured with calipers
- Center-to-center spacing between holes, measured in both X and Y axes
- Thread specification if the holes are tapped (e.g., M4×0.7, 6-32 UNC)
- Hole depth for blind tapped holes
- Mounting face indicating which surface of the equipment the mounting points are on (bottom, side, rear)
If your equipment uses DIN rail, rack-mount ears, or another standardized mounting system, note the standard and provide the specification. If no mounting points exist and the equipment will be foam-supported or strapped, note that as well.
5. Note Cable Routing Paths and Internal Clearances
A case that fits the equipment perfectly but leaves no room for cable management is a failed design. When you submit your measurements, include information about how cables will enter and exit the case, where they need to route internally, and what clearances they require. Key information to provide:
- Cable entry/exit points: which face of the case will cables pass through, and where?
- Maximum cable bundle diameter at each routing path.
- Minimum bend radius for stiff cables such as armored power cables or heavy-gauge wire harnesses.
- Cable lengths from connectors to their destination port and any internal cable management features.
For standard power and data cables, allow at least 25 mm of routing clearance. For dense wire harnesses or cables with large, molded connectors, plan for 40-50 mm. If you are unsure what clearances to specify, simply share your specific cable types.
6. Address Thermal and Environmental Requirements
From climate-controlled server rooms to outdoor field deployments and mil-spec transport applications, the thermal and environmental context will directly influence materials, wall thickness, sealing requirements, and ventilation design. Provide as much of the following as applies to your situation:
- Operating temperature range: the ambient temperature ranges to which the case and equipment will be exposed.
- Heat dissipation: does the equipment generate significant heat during operation? Note wattage if known.
- Ventilation requirements: does the equipment have fans or require active airflow? Note fan locations, airflow direction, and CFM if available.
- IP or NEMA rating requirements: is a specific ingress protection rating required for dust, water, or environmental sealing?
- Shock and vibration requirements: will the case be transported, rack-mounted in a mobile vehicle, or subjected to impact loads?
- EMI/RFI shielding: does the application require electromagnetic shielding?
Even if you don’t know the precise specifications, describe the deployment environment in plain language such as, “transported in a pickup truck bed to job sites,” “installed in a marine wheelhouse,” or “rack-mounted in a data center”. This gives technical packaging engineers an essential context for material and design selection.
7. Specify Operational and Access Requirements
Beyond physical dimensions, you should explain how the case will be used day-to-day. This informs key decisions around lid design, latch hardware, panel access, handle placement, and more. Ask yourself these key questions and document your answers:
- How often is the case opened? Daily, occasionally, or only for service or maintenance?
- Who opens it? Trained technicians, field operators, or end users who may not be familiar with the equipment?
- How does the equipment operate? With the case open, closed, or both?
- Are there display panels, touchscreens, or indicator lights? And do these need to be visible through the case wall?
- How will the case be handled?
- Will it be carried by hand, mounted to a vehicle, rolled on wheels, or stacked?
- Are there special security requirements?
Does the case need lockable latches, tamper-evident closures, or specific locking hardware?
8. Compile and Submit Your Measurement Package
Once you have gathered all measurements and operational notes, organize them into a clear submission package for the engineering team. A well-organized package leads to a faster, more accurate quote and reduces back-and-forth during the design phase. Your package should include:
- Dimensioned sketches or drawings showing top, front, and side views of the equipment with all major dimensions labeled.
- Face diagrams for each panel showing port and connector locations with offsets from a consistent reference corner.
- Mounting hole diagram with center-to-center spacing and hole/thread specifications.
- Annotated photos of the equipment from multiple angles. These are especially useful for communicating complex shapes or unusual features.
- Operational and environmental notes summarizing use case, deployment environment, and any special requirements
This guide provides everything a technical packaging engineering team will need for an accurate estimate of the costs and time required to design and build the custom case that your specific equipment, environment, and mission demand.
After You’ve Measured, Ask Us for a Quote
Packaging Strategies specializes in custom case design and fabrication for the full range of applications, from ruggedized field equipment to precision instrument enclosures and MIL-SPEC transport cases. The more complete your measurement package, the more precisely our engineers can scope your project and provide a technical packaging solution that will protect your equipment and provide the performance you require.
Reach out to us with your measurement package, and we’ll guide you through the next steps, from initial design concepts to final build and delivery.
Packaging Strategies:
- Phone: 410-547-7877
- Email: sales@psicases.com
Or: Start your same-day quote online
