7 Steps to Size a Desktop XYZ Platform for Vision Inspection and Assembly

1. Define the Job in One Sentence

Before opening any catalog, force yourself to write:
“Move a _ kg tooling set over × mm in X/Y and mm in Z, in seconds per cycle, with mm repeatability, in a __ environment.”
Example for a linear module for inspection machine:
“Move a 4 kg camera + light over 300 × 200 mm, Z travel 80 mm, in 1.0 s, with ±0.01 mm repeatability, in a clean electronics line.”
This sentence already tells you:
Approximate stroke of the XYZ linear stage
Payload mass and duty cycle
Precision and environment requirements
Every sizing decision on the desktop motion platform should point back to that sentence.

2. Step 1 – Workspace and Travel
   2.1 Map the field of view, not just the panel size
   For vision inspection, you care about:
   Part size or PCB panel size
   Field of view of your lens
   Overlap needed between images
   From that, derive required X/Y travel for the XYZ linear stage:
   X stroke = panel length – FOV + overlap
   Y stroke = panel width – FOV + overlap
   Add margin for clamps, fiducials and future product variants.
   2.2 Don’t forget Z for focus and assembly
   Z stroke must cover:
   Focus range (working distance of lens + variation)
   Clearance to load/unload parts
   Extra travel if you mount a robot gripper or electric cylinder on the Z axis for light pressing or pick-and-place.
   For a desktop motion platform, 50–150 mm Z travel is common, but calculate it instead of copying a brochure.
3. Step 2 – Payload and Tooling
   3.1 Build a mass budget
   List everything that moves with the carriage:
   Camera, lens, lighting
   Brackets, cable chain sections
   End-effectors (small robot gripper, screwdriver, dispenser)
   Safety covers or small nests
   Add them up with a safety factor (1.3–1.5×). This is the mass your linear module for electronics inspection actually sees.
   3.2 Translate to forces
   Rough rule:
   Required force ≈ mass × acceleration + friction + process forces
   If you want 4 kg to reach 0.8 m/s in 0.2 s, acceleration ≈ 4 m/s² → 16 N just to accelerate (before friction and margin). That drives your choice of motor size and whether you need a ball screw drive or timing belt drive on X/Y.
4. Step 3 – Drive Type: Screw, Belt or Linear Motor?
   4.1 Ball screw drive for precision and Z-axis work
   For short-to-medium stroke, high repeatability and vertical axes:
   Choose a ball screw drive linear module.
   It offers good stiffness and predictable backlash.
   Ideal for Z, and for X/Y on small PCBs or camera stages.
   This is the safe default for a linear module for inspection machine where ±0.01–0.02 mm repeatability matters.
   4.2 Timing belt drive for longer travel
   If your desktop platform needs 500–800 mm travel in X but only ±0.05–0.1 mm accuracy:
   A timing belt drive is lighter and faster.
   Less risk of screw critical-speed issues.
   Use belt on X, screw on Y and Z – a very common hybrid on desktop motion platforms.
   4.3 Linear motor if dynamics are your bottleneck
   When you’re doing high-speed web inspection or very fast scanning:
   A linear motor + encoder turns your axis into a direct-drive XYZ linear stage.
   No screw backlash, great velocity control.
   It costs more, but if throughput is king, it’s worth comparing linear motor vs ball screw for at least one axis.
5. Step 4 – Precision, Stiffness and Image Quality
   5.1 Look beyond positioning numbers
   Catalogs quote positioning accuracy, but for vision you should also ask:
   How stiff is the axis under camera load?
   What is the torsional rigidity of the profile and linear guide rail?
   How much does the carriage deflect at full extension?
   Any flex becomes blur in your images when you accelerate.
   5.2 Use wider rails and dual blocks when needed
   If your camera and light bar sit 150–200 mm away from the carriage center:
   Consider a module with twin linear guide rails or twin carriages.
   That’s standard on many high-end linear modules for inspection machines.
   It looks “overkill” on a CAD screenshot, but it’s cheaper than chasing ghost vibrations later.
6. Step 5 – Cycle Time and Motor Choice
   6.1 Work backwards from takt time
   Say each board needs 10 images, and the cycle time target is 12 seconds:
   Imaging time (exposure + processing) = maybe 6 seconds
   That leaves 6 seconds for all motion moves and settle times
   Simulate a simple motion profile:
   Move X, settle, snap; index Y, repeat
   From that, estimate required velocities and accelerations
   If your numbers look aggressive, you probably need a servo motor linear module on X at least, with decent tuning tools. Z and Y can sometimes run on closed-loop steppers if their moves are shorter.
   6.2 Don’t forget settle time
   It’s not enough to hit position; you must stop vibrating fast enough to take sharp images.
   Higher stiffness + servo control = shorter settle.
   Long, thin profiles and undersized motors = blurry frames.
   Always ask vendors for dynamic performance data on their desktop motion platforms, not just static specs.
7. Step 6 – Environment and Protection
   Even a “clean” electronics line has flux fumes and dust. For a platform that lives above open PCBs:
   Prefer at least a semi-closed or fully enclosed linear module on X and Y.
   Keep screws and belts covered; you don’t want grease above your product.
   If inspection runs inside a chamber, check for heat and solvent exposure.
   For harsher tasks (e.g., conformal coating or SMT machining), specifying an IP-rated linear actuator or sealed linear module for inspection machine is cheap insurance.
8. Step 7 – Controls, Cabling and Future Re-Use
   Your desktop motion platform will likely be reused for other fixtures later. Design for that:
   Use a controller that speaks your plant’s standard fieldbus and offers a clean API.
   Standardize coordinate systems and homing routines.
   Leave spare I/O for a future robot gripper, dispenser or extra camera.
   A well-thought-out desktop motion platform becomes a shared asset, not a one-off jig that dies with the first project.