Many machines need to measure linear travel — hydraulic cylinder stroke, lift height, gate opening, conveyor positioning. A glass scale can be costly and environment-sensitive; a wire draw position sensor (draw-wire box) is often the more economical, rugged choice: it converts linear travel into rotation via a cable, read by an internal encoder.
1. How It Works
Inside the box, a spring-driven spool pays out/retracts a cable attached to the moving part; the cable rotation drives an internal encoder. Linear travel = cable length per turn × turns. In short, a wire draw encoder is linear measurement performed by a rotary encoder.
2. KOSEND's Two Series
- HA155S (digital pulse): 0-10m range, incremental pulse output (voltage / NPN / PNP / push-pull / line-driver, DC5V or 8-24V), 0.01%FS linearity, 0.05% repeatability, IP54, 5M-cycle life — for general linear measurement.
- HP130 (industrial): 0-10m, IP64, 316 stainless cable, linearity ≤±6mm, hysteresis ≤4mm, repeatability ≤1mm. Digital output supports incremental and absolute (RS485/RS232/RS422/SSI/CAN); analog 0-5V/0-10V/4-20mA — easy PLC integration.
3. Selection Essentials
- Range & mounting: confirm max travel within range (0-10m); cable must be perpendicular to the outlet; never let it snap back freely.
- Output signal: incremental pulses for CNC/PLC; SSI/CAN/RS485 for distance or absolute position; analog 0-10V/4-20mA for legacy systems.
- Environment: oily/dusty workshops choose IP64 (HP130); consider housing and cable material outdoors/corrosive.
- Accuracy: 0.01%FS (HA155S) and ≤±6mm (HP130) satisfy most industrial linear needs.
4. Applications
Hydraulic cylinder stroke, lift/scissor platform height, gate and flap opening, material conveying positioning, test-rig displacement — KOSEND wire draw sensors support custom range and interfaces, supplied together with encoders and couplings.
Need a linear measurement solution? Call KOSEND at 400-100-6802 with your travel, accuracy and output requirements — we'll help you select.