Frequently Asked Questions

Simply adjust the "guide point" on the SCU6x touchscreen. The sensor stays fixed—no mechanical repositioning required. Width changeovers take seconds, not minutes.

The factor of safety (FoS) in actuator sizing serves a specific purpose: it provides margin for forces and conditions that are not fully captured by the model. The right FoS depends on how many of those forces you have actually modeled.

Simple mode — FoS 2.0 or higher:

The Simple calculator models only bearing friction and inertia. It does not account for web tension lateral forces, umbilical drag, floor grade, or bearing misalignment. An FoS of 2.0 compensates for these unmodeled terms. If you suspect unusually high secondary forces (heavy cable bundles, steep floor grade, old bearings), consider FoS 2.5 or higher.

Detailed mode — FoS 1.5 to 2.0:

The Detailed calculator models all six force terms explicitly: bearing friction, inertia, web tension lateral component, umbilical drag, floor grade, and misalignment. Because the model is more complete, a lower FoS is justified — typically 1.5 to 1.75. An FoS of 2.0 in Detailed mode is conservative and appropriate for critical applications or uncertain input values.

What the FoS covers in each case:

• Simple mode FoS — compensates for missing force terms plus measurement uncertainty
• Detailed mode FoS — compensates primarily for measurement uncertainty, bearing condition variation, and transient load spikes

A common mistake is applying an FoS to compensate for terms you should be modeling. If you know the web tension and wrap angle, model the lateral force directly in Detailed mode rather than inflating the FoS in Simple mode. The FoS should cover unknowns, not missing terms.

When in doubt, use the actuator sizing calculator in both modes and compare results. If they diverge significantly, the secondary forces are meaningful and Detailed mode gives the more accurate answer.

In chasing applications, process upsets can cause the web to wander significantly—due to splice passage, tension changes, or roll eccentricity. This exposes a critical weakness in narrow-range sensors:

• Narrow sensor problem: If the target (line, edge, or pattern) moves outside the sensor's field of view, the system loses tracking. With older controllers lacking edge-loss protection, the actuator continues driving in one direction until it reaches its limit—potentially damaging equipment or producing scrap.
• Roll-2-Roll® Sensors + SCU5/SCU6x advantage: Wide-range sensors (up to 960mm) provide a large capture window that maintains lock on the target during extreme wander events. Additionally, the SCU5 and SCU6x controllers include a "Lock on Lost Edge" feature that inhibits actuator movement if the edge is lost—preventing runaway conditions. For line/contrast guiding, loss of contrast also inhibits the actuator.

Example: An ODC 288 sensor provides 288mm of sensing range. If the web edge wanders ±100mm during a splice, the sensor never loses sight of it—and the controller keeps tracking smoothly.

Roll-2-Roll® Sensors provide true spatial awareness—not just binary on/off detection:

This accuracy is maintained across all material types without recalibration—critical for precision applications like battery electrode coating, optical film production, and high-speed converting.

Roll-2-Roll® Sensors can detect and track lines with a minimum width of 2 mm (0.08 in). The sensors also support negative space guiding—tracking the gap between printed features (such as the white space between labels) rather than a printed line. This eliminates the need to print a dedicated registration line, saving ink costs and allowing closer trim to printed edges.

The choice between edge guiding and line guiding depends on what defines "correct position" for your process:

Use Edge Guiding When:

• The physical web edge is your reference (e.g., die-cutting to edge, edge-aligned lamination)
• Material has consistent, clean edges
• Processing unprinted or solid-color materials

Use Line Guiding When:

• Processing pre-printed materials where print registration matters more than edge position
• Web edges are inconsistent (ragged, variable width) but printed marks are reliable
• Guiding to a coating edge rather than the substrate edge
• Running materials with printed registration marks or tracking lines

The Roll-2-Roll Technologies Advantage: With ODC 960 wide-aperture sensors, you can switch between edge and line guiding modes without changing hardware. This is particularly valuable for slitter rewinder applications that process both plain substrates (edge guide) and pre-printed materials (line guide) on the same machine.

The sensor automatically adapts to detect either the physical edge or a contrast line based on your selection in the SCU5 or SCU6x controller interface.

In Master/Slave guiding, timing is critical. The Slave guide must correct for a Master web movement at the exact moment that movement reaches the lamination nip.

The rule: Web path distance from Master Sensor → Lamination Nip should equal the distance from Slave Sensor → Lamination Nip.

Why it matters: If paths are unequal, the Slave might correct too early or too late (phase mismatch), causing misalignment at the actual lamination point.

The fix: If physical constraints prevent matching path lengths, Roll-2-Roll® Controllers can apply dynamic compensation—electronically delaying the feed-forward signal to match the transport time difference.

Yes. R2R offers upgrade kits that replace the sensor and controller on existing Fife, AccuWeb, or E+L web guides while keeping the mechanical actuator. Typical retrofit takes 2-4 hours.

Yes. Roll-2-Roll Technologies systems support multi-lane cascading alignment where each lane's edge position automatically sets the guide point for the next lane.

Example configuration (14 lanes):

• Each lane has two sensors: one monitors the "master" edge, one guides the web via a slave guide
• Lane 1's right edge position sets the guide point for Lane 2's slave guide
• Lane 2's right edge sets Lane 3's guide point, and so on
• Result: All lanes maintain edge-to-edge alignment automatically

For faster response: The SCU6x controller's industrial Ethernet connectivity enables a central PLC architecture where any lane change can instantly adjust guide points for all subsequent lanes simultaneously, rather than propagating lane-by-lane.

No. Traditional line sensors have narrow fields of view, requiring motorized positioning to physically move the sensor until it finds the line. Roll-2-Roll® Sensors have wide sensing ranges from 48 mm to 960 mm, allowing the sensor to see the entire potential line position area simultaneously. The sensor and controller automatically identify and track the line within this range—no mechanical movement required.

Roll-2-Roll® Sensors are essentially one-dimensional line scan cameras—but without the complexity of traditional machine vision systems:

This is a major unlock: sophisticated 1D imaging capability that production staff can set up and maintain without specialized training or ongoing support costs.

The RLA actuator converts rotary stepper motor torque into linear thrust using a belt-driven ballscrew (or roller screw) mechanism. The conversion follows a straightforward mechanical relationship.

The thrust scalar k relates motor torque to linear force:

k = R_belt × (2π / L) × η

Where:

• R_belt — belt reduction ratio (driven pulley teeth / motor pulley teeth). A 2:1 ratio doubles the effective torque at the screw.
• L — screw lead (linear travel per revolution), in meters. Smaller lead = higher force multiplication but lower speed.
• η — drivetrain efficiency, typically 0.85 to 0.90 for a ball screw with belt drive.

The belt reduction stage serves two purposes: it amplifies torque delivered to the screw, and it reduces reflected load inertia back to the motor by the square of the reduction ratio. Both effects allow a moderately sized stepper motor to produce thrust levels (800 to 2,000 lbf) that would otherwise require a much larger motor.

The compliance tradeoff — honestly: A belt introduces slight mechanical compliance compared to a direct-coupled design. Under sudden load changes, the belt stretches microscopically before the screw sees the full force. For high-bandwidth servo positioning, this would be a problem. For web guiding — where correction rates are 0.5 to 2 Hz and the web sensor outer loop corrects any residual error — this compliance is inconsequential. The belt's benefits (torque amplification, inertia reduction, compact packaging) far outweigh the compliance penalty at web guiding speeds.

The actuator sizing calculator uses this equation internally, with the correct k values for each RLA model, so you do not need to calculate it manually.

Telescoped (uneven) roll edges typically result from:

• Response lag: Hydraulic systems have inherent lag from valve response and fluid compressibility. By the time the guide reacts, the web has already wandered.
• Valve balancing issues: Unequal extension/retraction speeds cause inconsistent correction.
• Improper sensor mounting: If the sensor is fixed to the floor instead of the moving stand, or if the mounting arm is flexible, the system receives incorrect position feedback.

The Roll-2-Roll Technologies solution:

• Zero-backlash actuators: Electromechanical actuators respond immediately without the "spongy" feel of hydraulics
• Stiff control loop: Fast response prevents lag-induced wander, especially on outer roll layers
• Proper mounting guidance: Sensor on the moving stand, observing web at a fixed upstream idler, with structurally rigid mounting

The result is perfectly straight-sided rolls without the "drift" that causes telescoping during shipping and handling.

Roll-2-Roll® sensors work on nearly all web materials, including many that defeat conventional sensors:

• Clear films — PET, BOPP, cellophane, and other transparent materials work without special settings
• Mesh and porous webs — accurately measured where conventional sensors fail
• Metals and foils — aluminum, copper, steel strip
• Textiles and nonwovens
• Glass and carbon fiber

The patented light-scattering and spatial-filtering technology detects edges and features regardless of material opacity or surface finish. No recalibration is needed when switching between materials.

One capability is unique to Roll-2-Roll® sensors: detecting clear film edges under vacuum. Ultrasonic sensors cannot function without air as a transmission medium, and camera-based systems struggle with transparent materials. Roll-2-Roll® sensors are the only sensing technology that reliably detects clear films in vacuum environments.

The one challenging material is matte carbon black — the solution is to angle the light source perpendicular to the web to increase light scattering at the edge.

Chasing systems move heavy machinery (slitter bases, coating heads) rather than lightweight web rollers. This imposes strict mechanical requirements:

1. Structural rigidity: The carriage must be stiff enough that its natural frequency exceeds the control frequency (typically >25-50Hz). If the sensor bracket wobbles, it creates "false error" and causes oscillation.
2. Breakaway force: The actuator must overcome static friction in the linear bearings. Roll-2-Roll® Actuators provide up to 2,000 lbf (8,900 N) thrust.
3. Acceleration over speed: The actuator must change direction fast enough to match web error rates. Speed alone won't help if the carriage can't accelerate quickly.

Rule of thumb: If the system oscillates or hunts, check carriage rigidity first—it's the most common cause of chasing failures.

No. Roll-2-Roll® Sensors are available in apertures from 48mm to 960mm, allowing a single sensor to accommodate a wide range of web widths without repositioning.

For example, an ODC 288 sensor can detect edges anywhere within its 288mm (11.3 in) sensing range. Whether you're running a 100mm web or a 250mm web, the sensor detects the edge without adjustment.

This eliminates:

• Changeover time: No 2–5 minute delays for sensor repositioning between SKUs
• Operator error: No risk of incorrect sensor positioning
• Motorized positioners: No additional hardware cost or maintenance

Combined with material-agnostic detection (no recalibration between clear films, opaque substrates, or metallic foils), Roll-2-Roll® Sensors enable true "set and forget" operation.

No. Roll-2-Roll® sensors require zero code and zero calibration.

Traditional line scan cameras need a vision engineer, custom software, and careful calibration procedures. Roll-2-Roll® sensors take a fundamentally different approach:

• No calibration — the 1:1 magnification of the fiber-optic array means what the sensor sees is exactly what is there. No geometric correction, no lens calibration tables, no distortion compensation.
• No programming — adaptive edge detection algorithms are built into the controller firmware. Operators configure detection parameters through the SCU5 or SCU6x touchscreen interface or the 1DC built-in web interface.
• No vision expertise — setup takes minutes. Select the measurement mode, set thresholds, and the sensor is ready to run.

This simplicity is what makes Roll-2-Roll® sensors practical for inspection applications like splice detection, flag detection, and surface defect monitoring — you get vision-like capabilities without the vision system learning curve.

Bearing friction is typically the largest single force term in an actuator sizing calculation, and getting the friction coefficient right matters more than any other input.

Catalog values by bearing type:

• Profiled linear rail (recirculating ball) — μ = 0.003 to 0.005
• Cam rollers on steel plate — μ = 0.002 to 0.005
• Plain bronze bushings — μ = 0.10 to 0.20
• PTFE-lined bushings — μ = 0.04 to 0.10
• Roller bearings (cylindrical) — μ = 0.005 to 0.010

The critical reality: installed friction is 2 to 5 times catalog values.

Catalog friction coefficients represent clean, properly lubricated, perfectly aligned bearings under controlled conditions. In a production environment, actual friction is higher due to:

• Contamination (dust, web debris, adhesive residue)
• Inadequate or degraded lubrication
• Rail or bearing misalignment from installation tolerances
• Preload variation from mounting surface flatness
• Side-loading from web tension or mechanical misalignment

The Detailed calculator includes a k_install multiplier (default 2.0 to 3.0) that scales catalog friction to installed conditions. This is the single most important correction factor in the model.

Best practice: spring-scale pull test. Attach a calibrated spring scale to the carriage and pull horizontally at a slow, steady rate. The peak reading is your actual installed friction force. This 5-minute test eliminates the largest source of sizing uncertainty and is far more reliable than estimating from catalog values. If you can measure it, measure it.

Use the actuator sizing calculator with measured pull-test values in Detailed mode for the most accurate sizing result.

Both product lines provide the same edge detection accuracy and material versatility. The difference is in how they integrate:

ODC 96 Family

• Best for: End users who want easy setup with touchscreen interface
• Requires SCU5 or SCU6x controller
• Intuitive touchscreen operation
• No coding required
• Sensing ranges: 48-960mm

1DC 960 Series

• Best for: OEMs and technical users who prefer Ethernet/PLC interfaces
• All-in-one sensor (no external controller needed)
• Direct Ethernet connectivity
• EtherNet/IP, PROFINET, EtherCAT, Modbus/TCP
• Sensing ranges: 96-960mm

Both are priced similarly—choose based on your integration preference, not cost.

WPS (Web Position Sensor) series sensors have a resolution of 0.0635mm with ±0.25mm linearity across the full sensing range. The update rate is 500 Hz, providing fast response for high-speed applications.

Light source selection depends on your application:

• Infrared (880 nm): Best for most high-contrast applications including black lines on white, coating edges, and foil substrates. Works for both edge guiding and line guiding with the same sensor.
• White Light: Required for low-contrast patterns, subtle color differences, and applications where infrared cannot distinguish the feature.
• UV (385 nm): Required when the line is printed with UV-fluorescent ink that is invisible under normal lighting.

Contact Roll-2-Roll Technologies to discuss your specific material and line characteristics.

Roll-2-Roll Technologies electronic Master/Slave guiding eliminates the mechanical components that require constant maintenance in legacy systems:

Eliminated maintenance items:

• Motorized sensor positioner motors and drives
• Lead screws and anti-backlash nuts
• Sliding brackets and linear bearings
• Mechanical linkages between Master and Slave positions

What remains: Standard periodic inspection of sensors and guides—the same maintenance as any web guiding system, without the additional burden of sensor positioning hardware.

Typical customers report saving 10-20 hours annually in maintenance time previously spent on mechanical positioner systems.

Yes. Roll-2-Roll Technologies stepper-driven actuators routinely move loads exceeding 10,000 lb — and are rated for loads up to 30,000 lb on precision linear bearings. But the answer requires context, because the question conflates two different numbers.

Load weight vs. thrust force: A 15,000 lb roll on a shifting stand sits on linear bearings. The actuator does not lift this weight — it pushes the carriage sideways. The force required to move 15,000 lb on profiled linear rail with an installed friction coefficient of 0.005 is approximately 75 lbf of friction alone. Add inertia, web tension, umbilical drag, and a factor of safety, and the total thrust demand might be 200 to 400 lbf.

A stepper motor producing 7 Nm of torque through a belt-driven ballscrew with a 2:1 reduction can deliver 500 to 2,000 lbf of thrust depending on the screw lead and configuration. The motor is not straining against 15,000 lb. It is overcoming a few hundred pounds of friction and resistance force — well within its capability with margin to spare.

Field track record: Roll-2-Roll Technologies RLA actuators are deployed in hundreds of installations across converting, printing, packaging, and nonwoven lines. Many of these installations handle loads of 10,000 to 30,000 lb and have been running continuously for multiple years without motor replacement. The key to this reliability is conservative sizing at design time — ensuring the motor never operates near its pull-out torque boundary during normal corrections.

The actuator sizing calculator will show you the actual thrust demand for your specific load, bearing type, and operating conditions — and confirm whether the actuator has adequate margin.

Roll-2-Roll® sensors offer two integration paths, both providing real-time edge positions, width measurements, and inspection alerts to your PLC without middleware or custom drivers.

1DC Sensors — Direct PLC Connection

The 1DC has a built-in controller with an M8 4-pin network connector. It connects directly to your industrial Ethernet network via:

• EtherNet/IP
• PROFINET
• EtherCAT
• Modbus/TCP
• CC-Link IE Field Basic

This makes the 1DC ideal for OEMs and integrators who want a single-device solution with direct PLC communication.

ODC Sensors — Via SCU5 or SCU6x Controller

ODC sensors connect to an SCU5 or SCU6x controller via M12 12-pin Quick Disconnect Sensor Cable (up to 10 m). The controller then provides the network interface:

• SCU6x — dual industrial Ethernet ports, 4 digital inputs (NPN/PNP/dry contact), 3 digital outputs, plus web browser dashboard for remote diagnostics
• SCU5 — single Ethernet port (EtherNet/IP, PROFINET, or EtherCAT depending on variant) plus analog outputs (±10V, 0–20 mA)

Both paths deliver edge positions, width data, and inspection signals — including splice alerts, flag detection triggers, and defect notifications — directly to Rockwell, Siemens, Beckhoff, or any EtherNet/IP-compatible PLC.