ELEGOO Belt Tensioner for Neptune 4 Plus & 4 Max

The belt tensioner block for the big Neptune 4 Plus and 4 Max: a housing with an idler and a thumbscrew, so you set tension by hand with no tools involved. Tension drifts off on its own over time — the belt goes slack, echo starts trailing off corners, and long fast travels begin nudging layers out of line. You replace the whole unit when the thumbscrew thread strips, the housing cracks, or the screw spins free and simply won't hold tension anymore.

Specifications

• Thumbscrew tension adjustment, no tools required
• Drop-in replacement for the stock block on the frame extrusion
• ELEGOO factory part that isn't sold through official retail
• Fixes corner echo and layer shifts caused by a slack belt

Compatibility: ELEGOO Neptune 4 Plus and Neptune 4 Max. The listing title also mentions the Neptune 3, but that's machine translation noise — the photos show the big Neptune 4 block, so we don't list the Neptune 3 here. Match the housing shape and extrusion fit against the photos before ordering.