A register sensor can only control what the printed job makes detectable. Mark contrast, background, orientation, repeat distance and quiet area must be coordinated with sensor capability and the die-cutting control logic. Treat artwork and machine setup as one registration system.
This guide separates mark detection from web transport and cut geometry. A clean sensor signal does not prove correct encoder scaling or die position, while a wandering signal may begin with web movement rather than the artwork.
Decision matrix
| Layer | Evidence | Typical decision |
|---|---|---|
| Artwork | Mark dimensions, color, background and repeat | Can every production lot produce a clear optical difference? |
| Sensor | Light source, spot, teach values and output logic | Does the sensor switch once at the intended edge? |
| Web path | Lateral position, tension and flutter | Will the mark stay under the spot at operating speed? |
| Control | Input filter, correction limit and encoder scale | Is the correction applied to the right event and distance? |
| Cut result | Signed X/Y offset samples across the roll | Is error fixed, cyclic, drifting or random? |
Design a detectable registration mark
Use the sensor manufacturer’s mark guidance and test the actual printed substrate, not a screen preview. SICK describes register sensors as devices for optical non-contact mark detection and provides teach procedures based on the mark and background. Preserve a quiet area so graphics, seams or glare do not create extra edges.
Record mark orientation relative to web travel and the chosen detection edge. Keep this information in the artwork release file so later print changes do not silently alter registration behavior.
Mount and teach the sensor reproducibly
Set the prescribed working distance and spot orientation. Stabilize the bracket and cable so vibration does not move the sensing point. Clean the optics with the approved method before teaching.
Teach mark and background using production material. Record quality indicators or threshold values if available, plus light-on/dark-on logic. Verify a single, repeatable output transition through several repeats.
Separate lateral and machine-direction error
If the mark moves sideways under the spot, check edge guiding, roll loading and web tracking before increasing sensitivity. If it remains centered but the cut shifts along travel, inspect repeat length, encoder contact, scale and correction timing.
Plot signed cut offset against repeat number. A constant offset suggests a datum adjustment; gradual drift suggests scale or tension; a repeating wave may point to mechanical or roll-related periodicity.
Validate from setup speed to production speed
Use a controlled roll segment and measure actual blanks. Speed can change flutter, tension and response timing, so release cannot rely on slow jog alone. Confirm that correction limits do not chase a false mark or create abrupt web movement.
Retain the approved mark sample, teach record and cut map. If a new ink, varnish or substrate changes reflectance, repeat the detection study rather than copying the old threshold.
Write a job-level registration standard
The job sheet should specify mark artwork, sensor location, teach method, expected signal, encoder scale reference, correction range and cut acceptance method. Separate these job parameters from protected machine calibration.
Continue with the linked web-tension guide when registration moves with roll diameter or speed. HANNAI can review machine and job requirements when configuring a roll-fed die-cutting project.
Technical references
- SICK register sensor operating instructions — used for the general component principle; the installed machine documentation remains controlling.
Related machine and guide
Review the 850 roll die cutting machine for machine context, then use the web tension and register control guide for the adjacent maintenance or process check. Browse all Buyer Guides when building a wider project checklist.
Frequently asked questions
Can any dark rectangle be used as a register mark?
Not reliably. Confirm contrast, size, orientation, background and quiet area with the actual sensor and printed substrate.
Should sensitivity be increased when the mark wanders?
First determine whether lateral web movement, flutter or contamination is moving the mark away from the spot.
What does a constant cut offset indicate?
It often points to a datum or timing offset, but confirm die geometry and measurement method before adjustment.
Must a new varnish or substrate be retested?
Yes. Reflectance and contrast can change even when the artwork file is unchanged.
Review your machine configuration with HANNAI
Send the machine model, cup or material drawings, component labels, photos and a description of the required result. We will clarify which details must be confirmed before a quotation or technical recommendation.