S500/S550 Replacement Arm, 233mm, Nylon with Carbon Fiber Rod

This replacement arm fits the S500 and S550 multirotor frame family, letting a crashed arm be swapped out individually rather than needing to replace the whole frame after a hard landing. At 233mm long and 40mm wide, it's sized specifically for these two closely related frame models, which share the same arm geometry despite their different overall wheelbase sizes.

Construction combines glass fiber and polyamide nylon in the arm body, with a carbon fiber rod running through its center for added rigidity, a composite approach that balances cost, weight and stiffness better than a single-material arm would. The arm carries a slight upward sweep along its length, giving the frame a dihedral effect that genuinely aids flight stability, similar to how dihedral wings improve stability on a fixed-wing aircraft, rather than being purely a cosmetic design choice.

Pre-threaded brass sleeves are molded into the arm at the frame bolt points, so the mounting hardware threads directly into metal rather than into the nylon body itself, which would wear out and strip after repeated assembly and disassembly. The motor mounting hole is a 3mm diameter, matching standard motor mounting bolt sizes used across most multirotor motors in this size class. The arm weighs 48g.

Builders and repair shops working with S500 or S550-based multirotors who need a correctly sized, reinforced replacement arm rather than attempting a repair with mismatched or generic parts will find this arm a direct, properly engineered fit.