North Sails – 3Di Windsurf Adjustable Molding System
At a Glance
Designed and built a discretely adjustable 3D mold for composite sail manufacturing with 58 individually controllable actuators.
Developed a precision surface-shaping system with accuracy to ±0.5 cm, enabling molding of any sail profile from a single tool.
Engineered an integrated heating and vacuum curing system to cure sails at 100 °C in under 7 minutes.
Created a Linux-based graphical user interface (GUI) for simple operator control of actuators and curing process.
Increased production capacity to 40+ sails per day, enabling scalable manufacturing of 3Di windsurf and dinghy sails.
Delivered a cost-efficient, reconfigurable mold that eliminated the need for costly, single-purpose composite molds and enables brand new sail shapes to be created by simply uploading a new configuration.________________________________________________________
My Role
Project Context North Sails is a global leader in high-performance sail manufacturing and the inventor of 3Di composite sail technology—a process that molds sails in three dimensions using precision-laid composite fibers and advanced resin. This technology produces sails that are lighter, stronger, and more durable than traditional Dacron or Mylar sails, and it dominates the professional racing scene from superyachts to TP-52s.
However, 3Di had been largely out of reach for smaller classes like windsurfers, dinghies, and kites. The main barrier was manufacturing economics: existing 3Di molds were enormous, single-purpose, and optimized for large yacht sails. Producing small sails on this equipment was slow, costly, and impractical.
The Challenge I was brought in to help adapt 3Di technology to small-format sails by developing an adjustable molding system that could replicate the precise curvature of any sail profile. The system needed:
Universal compatibility with any windsurf or dinghy sail shape.
Precision surface control within ±0.5 cm over a 25 ft span.
Fast reconfiguration for rapid design iteration.
Integrated curing capability for high-throughput production.
Engineering the Solution
Adjustable Mold Design: We built a 10 ft × 25 ft molding table with 58 independently controlled actuators, each able to position the mold surface to match any CAD-defined sail shape.
Integrated Heating & Vacuum Curing: Designed a dual-silicone blanket and heat-blanket system to cure sails in position at 100 °C under vacuum. This reduced cure times to 7 minutes and allowed two people to complete a sail in under 30 minutes.
User-Friendly Control System: Created a Linux-based controller with an easy to use GUI so operators could load sail designs, adjust actuator positions, and control heating/vacuum processes without deep technical training.
Rapid Iteration & Scalability: Enabled testing of dozens of sail profiles within the first month, paving the way for a production capacity of 40+ sails/day.
Impact This system unlocked affordable 3Di technology for windsurfers and other small sails, eliminating the need for multiple fixed molds or taking up space on the massive superyacht mold.
It also allows for new sail models to be tested and brought to production quickly. To generate a brand new sail shape, you need only upload the new configuration file and watch the mold take shape.
The project combined mechanical design, precision mechatronics, control systems, and manufacturing process engineering—and transformed an elite technology into a scalable, mass-market product.
This system has worked reliably for 5 years now pumping out windsurf sails around the clock. And fortunately, I've 'barely' recieved 2am calls from Sri Lanka asking for debugging help when the machine malfunctions.
