What Makes Medical Automation So Demanding on Linear Modules?
2025-11-26What Is a Linear Module? A Practical Guide for Machine Builders
2025-11-28Step 1 — Set priorities (goal → direction)
Precision & cleanroom first (assembly, bonding, imaging): lean toward W-Robot VGTH fully enclosed ball-screw modules with high-resolution feedback and thermal compensation.
Long stroke & throughput first (transport, buffering, loading): lean toward W-Robot EB/OB timing-belt modules, paying attention to belt tension, rail pairing, and end-of-stroke buffering.
Ultra-smooth low-speed or high dynamics (sensitive dispense/inspection paths): evaluate W-Robot VL/VGL linear-motor platforms as an alternative where needed.
Internal links
• Product Center: https://www.w-robot.com/Products/Products.html
• Solutions Hub: https://www.w-robot.com/Solution/Solution.html
• Cross-link later: Day 1 “Complete Selection Guide” (add after publishing)
Step 2 — Convert goals into parameters (make it calculable)
Load & COG → required thrust/torque
Define load mass, COG, stroke, and mounting; derive target speed/accel from cycle time, then map to thrust/torque.
Cycle formula → motion profile & settling
Cycle = motion time (incl. accel/decel and settling) + process time + margin. Treat settling time as a separate KPI for assembly/vision stations.
Precision metrics → R/A & speed ripple
Use repeatability (R) as the primary acceptance metric; handle accuracy (A) via fixtures/calibration. At low speed, watch speed ripple (RMS).
Environment constraints → sealing/lubrication/materials
For clean zones, prefer fully enclosed or sealed covers; specify low-volatility lubricants and list approved cleaners in the BOM.
Step 3 — Decide with scenarios (examples)
Dispense / bond / imaging: stable low-speed segments and reliable settling → W-Robot VGTH ball-screw; consider VL/VGL if ultra-low ripple is required.
Long-stroke transport / buffering: cycle uniformity and easy upkeep → W-Robot EB/OB timing-belt, with proper tensioning, rail pairing, and end buffers.
Retrofit in clean areas: minimize downtime → W-Robot VGTH with universal mounting patterns and interface adapters.
Quick comparison table
| Dimension | W-Robot Ball-Screw (e.g., VGTH) | W-Robot Timing-Belt (e.g., EB/OB) |
|---|---|---|
| Repeatability (R) | Micron-class potential; suited to assembly/bonding/imaging | Moderate; suited to transport/buffer |
| Low-speed smoothness | Easier to control; predictable settling | Requires extra tuning for tension/control |
| Speed / Stroke | Moderate speed; controlled settling | Higher top speed and long stroke friendly |
| Cleanroom / sealing | Fully enclosed options available | Shrouds possible; best for moderate clean needs |
| Maintenance focus | Lubrication & rolling elements | Belt tension, sliders, end-buffer health |
| Typical stations | Assembly, bonding, imaging | Transport, buffer, load/unload |
Final choice depends on load, stroke, cycle, and cleanliness class.
Common pitfalls (and fixes)
Chasing max speed only → include settling time in the cycle KPI.
Focusing on absolute accuracy only → make R the core spec at critical stations; handle A via calibration.
Treating cleanliness as an add-on → put sealing, lubricant type, and cleaner compatibility into the BOM and acceptance plan.
Ignoring resonance → sweep tests for multi-axis/gantries; apply master–slave sync and avoid structural resonances.
RFQ checklist (copy into your brief)
Load (kg) & COG, stroke (mm), mounting orientation & envelope
Target cycle and settling time, speed/accel profile
R/A targets and test method (fixture, sampling)
Environment: cleanliness class, approved cleaners, noise limits
Controls: fieldbus/I/O, sync strategy, limits/E-Stop/force monitoring
Maintenance: counters for distance/hours, relube interval, consumables
W-Robot resources
W-Robot Product Center (ball-screw / timing-belt / linear-motor): https://www.w-robot.com/Products/Products.html
W-Robot Solutions (gantry, cleanroom, etc.): https://www.w-robot.com/Solution/Solution.html
Cross-link after publishing: Day 1 “Linear Module Selection—From Load & Speed to Precision”
Optional FAQ (JSON-LD ready)
When should I prefer a ball-screw module?
When micron-class repeatability, cleanroom sealing, and controlled settling windows are key (assembly, bonding, imaging).
When should I prefer a timing-belt module?
When long stroke, cycle uniformity, and easy maintenance matter most (transport/buffer), with correct tensioning and end buffering.
