Define geometry
Mandrel radius, cylindrical length, dome type, boss opening, and coordinate frame determine the feasible surface paths.
The filament winding loop.
A useful winding tool cannot stop at drawing curves. It has to connect structural intent, process constraints, laminate buildup, and the actual machine motion that deposits tape on the mandrel.
Select process
Fiber, resin, tape width, thickness, friction assumption, and consolidation method define the production envelope.
Plan pattern
Hoop and helical angles, skip/cycle integers, and coverage must close into a repeatable pattern without unacceptable gaps.
Validate laminate
Finite-width rovings accumulate thickness unevenly, especially near polar regions and dense dome turnarounds.
Simulate machine
Generated motion needs axis limits, correct tangent tape delivery, visible moving joints, and controller-ready output.
Published AddWind visual guides.
The first AddWind learning series is now live. These guides use AddWind simulator screenshots and conservative literature-grounded explanations for the core decisions behind filament winding.
What is Filament Winding? A Visual Guide for Engineers
Filament winding makes hydrogen tanks, COPVs and rocket motor cases by wrapping continuous fibre onto a rotating mandrel. An engineering walk-through with a browser-based 3D simulator.
The Filament Winding Machine, Explained Axis by Axis
2-axis, 4-axis, 6-axis robotic — what each axis on a filament winding machine does, how the payout eye decides where each turn lands, and how to read a winding job from a planner.
Hoop, Helical and Polar Winding Patterns Explained
The three families of filament-winding paths — hoop, helical and polar — what each one carries, when to pick which, and how to combine them into a real pressure-vessel laminate.
Why the Winding Angle Matters in Filament Winding
Winding angle drives whether your fibre will even reach the dome. A visual explanation of Clairaut's relation, the boss-radius limit, and how 3° can move a part from windable to impossible.
Pattern Closure, Skip Cycles and Coverage in Filament Winding
What N, S and cycles actually mean in filament winding software. A visual guide to pattern closure, skip cycles, and how the cylinder gets uniformly covered.
Tape Width, Thickness, Gaps and Overlaps in Filament Winding
Real fibre is a band, not a line. How band width, thickness, gaps and overlaps decide laminate quality, and how to see them in a winding simulator before they show up on the part.
Dome Turnarounds and Polar Buildup in Filament Winding
Why every wound pressure vessel has thicker domes than cylinder, what happens at the boss turnaround, and how dwell strategy controls polar buildup.
From Simulation to Machine Program in Filament Winding
How a filament winding simulation becomes a real machine program. The dry-run, the motion analysis, the export, and what to verify before you cut metal.
Start with filament winding 101.
The broad AddComposites filament winding guide is the right entry point for outreach. AddWind should extend it with visual sub-lessons that use simulator screenshots, simple charts, machine playback clips, and diagrams before asking readers to care about advanced verification.
What happens inside a filament winding machine?
A beginner-friendly walkthrough of creel, resin bath or prepreg tow, tensioning, carriage motion, rotating mandrel, payout eye, and CNC control.
- Use AddWind gantry playback screenshots.
- Show a tape-width strip touching the mandrel.
- Include one real machine photo for context.
Hoop, helical, and polar winding visually explained
Show the difference between common winding patterns with one consistent AddWind vessel view and one developed-path chart.
- Hoop winding for circumferential strength.
- Helical winding for combined axial and hoop loading.
- Polar winding around dome openings.
Why winding angle matters
Explain how 15, 30, 55, and 90 degree layers look, why they carry load differently, and why software must inspect the actual path.
- Capture the same project at several angles.
- Add a simple load-direction diagram.
- Link each visual to a simulator preset.
What pattern closure means
Turn skip, cycle, coverage, and closed-pattern selection into a visual explanation that a non-specialist can understand.
- Use the AddWind results table.
- Show closed versus poor candidate overlays.
- Explain why a pretty path can still be wrong.
Core concepts engineers need.
These chapters are based on the local key-paper library and the AddWind implementation work already done for winding paths, transitions, thickness texture, and 4-axis playback.
Ideal paths versus real rovings
A zero-width fiber path is mathematically convenient, but a real band has finite width and thickness. The effective polar opening shifts, the centerline is not exactly tangent to the opening, and the visible laminate can differ from the ideal trajectory.
- Track actual band width, not only centerline angle.
- Expect polar crowding as the same band turns around a shrinking radius.
- Use thickness-aware visualization to reveal where ideal theory stops matching production.
Mandrel geometry and surface coordinates
Cylinders are straightforward because radius is constant. Domes introduce curvature, changing parallel radius, local surface normal, and the minimum path angle near the boss.
- Use station and circumferential wrap to inspect developed paths.
- Compute surface normals before applying thickness offsets.
- Separate cylinder, front dome, and back dome behavior in diagnostics.
Geodesic and non-geodesic winding
Geodesic paths are stable without lateral friction. Non-geodesic paths can be manufacturable, but only when the required slip resistance stays inside the available friction window.
- Clairaut-type relationships define the geodesic baseline.
- Deviation from that baseline should be visible in angle plots.
- Friction-guided transitions need explicit pass/fail criteria.
Pattern closure and integer matching
A winding pattern is not complete until the skip, cycle, and circuit counts produce acceptable coverage. Structural layer requirements must be reconciled with the integer pattern that the machine can actually repeat.
- Search candidate skip/cycle pairs instead of relying on one default.
- Evaluate coverage, gap risk, fiber length, and angle deviation together.
- Keep pattern selection reproducible in saved projects.
Transitions between layers
Real winding often cannot cut fiber between layers. The connecting path has to move from one endpoint and angle state to the next without a discontinuity that the material or machine cannot follow.
- G0 continuity removes positional jumps.
- G1 continuity keeps the tangent direction physically plausible.
- Hoop starts must respect the actual end side of the previous transition.
Thickness distribution and polar buildup
Thickness is not uniform along a wound vessel. Dome regions can become dense because many circuits converge near the polar opening, while hoop layers mostly build the cylinder.
- Map thickness per surface station and circumferential zone.
- Do not show buried lower layers as if they remain visible.
- Use completed-laminate texture for inspection and live tape for production playback.
Machine kinematics and payout tangent
The visual machine model is not decoration. Operators need to see the rotary axis, carriage motion, vertical payout position, yaw orientation, and tape strip meeting the same contact point used by playback.
- Mandrel rotation and carriage position should match path samples.
- The payout eye must face the tangent direction, including direction flips.
- Axis limits and feed modes should be visible before exporting controller code.
Program generation and verification
The last mile is controller confidence. Generated output needs the right units, coordinate conventions, feed interpretation, axis naming, and syntax for the target machine.
- Restore CCDF, part-program, and Siemens/SINUMERIK-style outputs.
- Compare with real controller expectations from machine users.
- Keep verification tied to a saved AddWind project state.
Advanced software and verification series.
These articles are better for engineers who already understand the process and are evaluating software. They should sit after the 101 series, with links back to simulator projects and pilot feedback.
Article 01 / live draft
Filament winding software is becoming the production bottleneck.
Why path drawing is no longer enough, and why modern winding software has to verify laminate, transitions, machine playback, and export packages together.
Geodesic vs non-geodesic winding
How to decide when friction assumptions are acceptable and how to inspect the angle profile.
Finite tape width changes everything
Why real roving width and thickness expose gaps, overlaps, polar buildup, and false coverage.
From winding path to machine motion
What payout tangent, yaw, carriage, rotation, axis limits, and dry-run export need to prove.
How to evaluate winding software
A buyer checklist for closure, thickness, transitions, machine playback, export, and project persistence.
What modern winding software must prove.
A premium filament-winding product should make engineering risk visible. AddWind should not merely calculate a pretty path; it should explain why a path is windable, how the laminate builds, and whether the machine can execute it.
GeometrySurface coordinates, dome zones, boss openings, normal vectors, and effective polar radius are explicit and inspectable.
PathHoop, helical, geodesic, non-geodesic, and transition paths report coverage, angle deviation, and friction/slip margin.
LaminateThickness mapping shows polar buildup, avoids visual bleed-through of buried layers, and supports completed-layup inspection.
MachinePlayback synchronizes contact point, tape strip, payout eye, carriage, rotary axis, yaw, and axis-limit feedback.
OutputGenerated code is tied to a saved project and verified against real machine coordinate systems and controller dialects.
The key lesson from finite roving theory.
The extracted 2004 source emphasizes a practical problem that appears throughout AddWind: an "optimal" vessel by ideal structural theory may not be optimal once roving dimensions, pattern integers, transition friction, excessive roving length, and non-uniform thickness distribution are considered. That is exactly why the software needs pattern search, friction diagnostics, thickness preview, and machine playback in one workflow.
Reference library behind this guide.
The local paper folder groups the literature into design theory, path calculation, robotic winding, thermoplastic processing, low-cost machinery, and process comparisons. These references should drive the deeper lesson pages over time.
Design theory and pressure vessels
Netting theory, isotensoid pressure vessels, design principles, finite roving geometry, and laminate efficiency.
Core theoryThickness
Path calculation and dry winding
Geodesic and non-geodesic path planning, dry fiber winding opportunities, and manufacturability limits.
Path planningFriction
Robotic and 4-axis winding
Offline programming, robotic filament winding cells, industrial RFWT applications, and machine coordinate systems.
KinematicsProgram output
Thermoplastic and consolidation
Thermoplastic composite filament winding, in-situ consolidation, roving processing, and AFP comparisons.
MaterialsProcess window
Equipment and startup machines
Low-cost filament winding technology, laboratory equipment, cylinder manufacturing machines, and practical build constraints.
MachinesValidation
Applications and process comparison
Pressure vessel challenges, square tubes, filament winding applications, and filament winding versus fiber placement.
ApplicationsUse cases
- Application of Filament Winding Technology in Composite Pressure Vessels and Challenges - A Review, 2022
- Design and Off-line Programming of a Robotic Tape Winding Cell, 1995
- Design Principles in Filament Winding, 1994
- Modeling of Thermoplastic Composite Filament Winding, 2000
- Filament Winding - A Unified Approach, 2004
- Path Calculation Technology and Opportunities in Dry Fiber Winding: A Review, 2018
- Robotic Filament Winding Technique in Industrial Application, 2018
- Robotic Filament Winding: An Innovative Technology to Manufacture Complex Shape Structural Parts, 2019
- Filament Winding and Automated Fiber Placement with In Situ Consolidation, 2021
- Processing Continuous Rovings - Manufacturing Technologies Overview, 2021
- Low-Cost Filament Winding Technology for Universities and Startups, 2022
- Composite Filament Winding, 2011
- Analysis of Filament Winding Processes and Potential Equipment Technologies, 2017
- Filament Winding versus Fiber Placement Manufacturing Technologies
Use the guide with a real AddWind project.
Open the standard project library, then inspect the same concepts in the simulator: pattern closure, thickness texture, and production playback.