Project G

New Machine - High-Precision Fibre Optic Cable Armour Extrusion & Winding 

Project Overview  

This project focused on developing a specialised fibre optic cable protected by two critical sheathing layers: a nylon protective sheath and a structural Teflon outer sheath. Due to the sensitive nature of the cable and its intended application, both sheathings had to be extruded with exceptionally high precision and consistency. 

Nylon Sheathing: Precision at the Micron Level 

The first stage required the nylon sheathing to be extruded directly onto the fibre optic cable with a tolerance of ±4 microns—a micron being just 1/1000th of a millimetre.

A lubricating layer was applied between the cable and the nylon sheath to allow movement without damaging the delicate fibre optic core. Achieving the required tolerance was essential for maintaining the cable’s performance and preventing micro-damage during use. 

Teflon Sheathing: Structural Strength & Spherical Accuracy

A structural Teflon layer was then extruded over the nylon sheathing. This outer layer allowed the cable to withstand pulling forces and mechanical stress, including being wound over a spherical component, commonly referred to as a barrel.

To meet performance requirements, the Teflon sheathing needed to be applied perfectly uniformly and spherically around the nylon layer. Any deviation in shape or width could compromise the precision winding process and risk damaging the cable. 

Why Spherical Accuracy Matters 

Both sheathings required flawless uniformity to ensure controlled winding. If the cable’s diameter varied, even slightly: 

• The winding process would lose precision 
• Cable storage would become inconsistent 
• The risk of mechanical stress and fibre damage would increase 

Maintaining consistent cable geometry was therefore essential for both manufacturing and operational reliability. 

360° Rotation Winding Process 

As the cable was wound around the barrel, it needed to rotate a full 360 degrees for every wrap. This ensured the cable remained untwisted during storage and could be released smoothly, dramatically reducing the likelihood of damage during deployment. 

Ongoing Research & Development 

To achieve the extreme accuracy required at every stage—extrusion, lubrication, sheathing, and winding—Custom Controls undertook significant research and development throughout the project. This included refining processes, testing tolerances, and validating the performance of the final cable design.