About

Embed a continuous strand of fiber into plastics
2 nozzles - one for plastic and another for fiber?
https://www.compositesworld.com/blog/post/3d-printing-composites-with-continuous-fiber
pAtENteD !
If glass fiber is 500ksi - then embedding glass fiber would yield the strength of steel if used at 10% of thickness

How it Works

Chat - [1]

Separate fiber and plastic nozzles. Fiber nozzle has cutoff mechanism. https://chatgpt.com/share/6974dd60-eff4-8010-9fe9-14e472e6d6ed. This one uses carbon fiber or glass fiber.
Do others have plastic-embedded fiber? Would be easier on controls if cutting can happen.
Lowest brow version would be continuous print without cut or with human assisted cut, and no filament breaks during print.
Tensile stronger than mild steel.
30% fiber in continuous fiber prints - [2]
Nylon is best plastic, as it's polar like glass
Steel isn't great - doesn't bond well to plastic like fiberglass.
Spring steel - 0.4 mm at $40/lb at McMaster [3]. Or 0.5 mm at $20/lb.
Stranded stainless - $10/lb from china - [4]